CalcTape for Android

Updated: 9 October 2026 · CalcTape for Android 7.2

CalcTape for Android is the mobile version of the CalcTape calculator. Instead of showing only a single intermediate result like a conventional calculator, CalcTape works like a paper tape with a notepad function: you write your calculation line by line, can add a comment to every value, and edit anything at any time. Everything is recalculated instantly.

Calculate, Comment, Correct: on your phone or tablet. Your documents stay local on your device.

What's new compared with version 7.1?

• Named values work above their definitions, and circular references are detected. See Variables.
• Automatic number detection on paste is free in every edition. See Settings.
• Six ready-made calculations make it easier to get started. See Quick insert.
• Headings and emphasis format text and comments. See Comments.
• Operators in comments: the “+” button above the system keyboard keeps operators in a comment as text. See Comments.
• Cursor when opening a document: last position, start of the document or an empty line at the end. See Settings.
• Wide values widen their calculation: the column of a calculation grows with its widest value or longest name. See Line structure.
• Two additional colour palettes extend the Modern design. See Design and themes.

1. The concept: how CalcTape works

CalcTape differs from a conventional calculator in five ways:

Line-by-line calculation

Each line contains an operator and a value, e.g. + 1,350.00. CalcTape accumulates the lines continuously, like a receipt.

Automatic subtotals

When you close a block (using the = ↵ key), CalcTape automatically draws a separator line and writes the running subtotal below it:

+ 3,230.00 Salary
- 1,350.00 Rent
-   780.00 Groceries
════════════════
+ 1,100.00 Available

Comments right next to the numbers

You can write any text after a value (in the example above "Salary", "Rent" …). CalcTape ignores the text when calculating but displays it alongside the numbers, so every calculation stays easy to follow.

Edit anything at any time

Tap any value in any line and change it. The entire calculation is recalculated instantly. That is what makes CalcTape so flexible.

Multiple calculations side by side

• Without a blank line between two blocks you get a convenient subtotal.
• With a blank line you start a completely new, independent calculation in the same document.

2. The editor: writing calculations

The editor is the heart of the app. Type with the CalcTape keypad or switch to the system keyboard with the ABC key for comments and names; both work equally well. Totals are displayed in bold, so the result of every calculation is easy to spot at a glance.

Line structure

<Operator> <Number> <optional comment text>

Example: + 1,234.50 income March

• Every calculation must start with a number or a sign (+ / −).
• Available operators are addition, subtraction, multiplication, division, and exponentiation.
• The decimal and thousands separators follow your device language. Settings also offer Indian digit grouping (lakh/crore, e.g. 10,00,000.00).
• The numbers of a calculation line up in one column. A wide value or a long name widens the column of its calculation, divider lines included, and it shrinks again when less space is needed; other calculations keep their width.

Percentage calculations

A percentage value is placed after a number, e.g. - 40.00%. It refers to the current running subtotal:

 +        910.50 Available budget
 -         40.00% → -364.20  Reserves
 ═══════════════
 +        546.30 Available

CalcTape automatically displays the amount calculated from the percentage right after it, drawn as → -364.20 in a softened shade of the total's color, or of the negative color for a negative amount, as here. In the line with the cursor it reads | -364.20, which is how the text holds it and what copying takes. Every other value CalcTape fills in behind a | appears the same way.

Comments

Everything after the number is treated as a comment and does not affect the calculation. Lines that start with neither a number nor an operator are free text: use them for headings and notes. Definitions and lines that start with a name are the exception (see Variables).

An operator typed behind a number starts a new calculation line, even in the middle of the comment. To keep it in the comment as text, as in “rent + heating”, tap "+" in the result bar first. The button is there while the system keyboard is open, in place of ABC. While it is on, every +, -, * or / you type on the system keyboard stays in the comment as text. It goes out when you tap it again, press Enter or leave the line you typed in; closing the system keyboard and opening another document switch it off as well. Until the first operator, you can still move the cursor to the spot in the comment. The first time you switch it on, a speech bubble explains the button.

A text line starting with a hash (# Q1 Forecast) is a heading and is shown in bold; several hashes (##, ###) work the same way. On top of that, **bold** and *italic* apply in text lines and in the comment behind a number, and the underscore spelling __bold__ / _italic_ does the same, except inside a word, so names like net_total are left alone.

The characters themselves disappear from view while the caret is in another line; the moment it enters the line they are back. They are in the document either way: selecting, copying and saving take every character along. A star between blanks stays an operator, so 2 * 3 is not emphasised. Exporting and printing carry the emphasis along and leave the characters out.

Variables (named values)

CalcTape lets you name values and reuse them anywhere in the document, above the definition as well as below. Variable names start with a letter and contain letters, digits, and underscores, and are not case-sensitive: CalcTape harmonizes the spelling to match the definition.

vat = 19
+ 1,000.00 Net
+ vat% → +190.00 VAT

A name resolves even before the line that defines it. A definition that ends up depending on itself is marked as an error; with the cursor in that line, the description reads Circular reference. Above its definition, a line that starts with the name stays plain text, handy as a heading; below the definition it calculates with the value.

In a sum line, the name can also go to the right of = and takes on the result of that line (+ 1,880.00 = budget). The Free edition allows up to 2 variable definitions per document; Pro has no limit.

Quick insert

The small floating button on the right edge of the tape opens a panel with two sections. Tap a section heading to collapse or expand it: Info starts collapsed, Named values expanded, and the panel remembers your choice. The button can be hidden in Settings → Tape → Show quick insert button, and it can be moved: long-press it and drag. A short vibration confirms that it has come loose, and the position is remembered as a proportion of the screen, so it survives rotation.

Info lists ready-made calculations that come with CalcTape in your language: a shopping list, a price calculation, travel expenses, a quote, VAT and discounts. Tapping one puts it at the top of the current document, with an empty line between it and what is already there, so both keep their own results. The caret then stands on its first calculation line, right behind the first number: change it and everything below recalculates. The quote works with three variables, so in the Free edition it carries the Pro diamond and a tap on it leads to the upgrade dialog.

Named values lists every variable defined in this document, name on the left and current value on the right. Tap the name to insert it at the caret, tap the value to jump to the line where the variable is defined, and use New variable at the top of the section to start a fresh definition: it asks for a name, and with the cursor in a calculation it names that calculation's total (= name on the sum line), otherwise it inserts name = 1. In the Free edition the first two variables behave normally; from the third one on, the rows lead to the upgrade dialog, and so does New variable once two variables exist.

Editing, inserting, deleting

• Tap anywhere, place the cursor, and overwrite the value; CalcTape recalculates immediately.
• Long-press a number to select it, then drag the handles to widen the selection.
• The backspace key is block-aware: on a divider or sum line it removes the divider and the total and opens the calculation again, while its lines stay; inside a number it deletes one digit at a time, and it skips the alignment spaces in one step.
• Numbers pasted from elsewhere are adapted to your number format: 1.234,50 becomes 1234.50; something ambiguous such as a lone 1,234 stays as it is. This automatic number detection is on by default; the first paste that changes a number says so once, with a button to the setting (Settings → Calculation).

3. The keyboards: all keys explained

The keypad has three segments, and you decide which layout sits in each of them. Each segment remembers the layout you last put in it. Since version 7.1 every built-in layout is available in every edition.

To move between the segments, swipe left or right across the keypad itself, which brings up the next segment, or tap the segment button (K1, K2 or Nav) in the result bar for a short list naming the layout in each segment; a tap on an entry brings that segment up. While the system keyboard is open or the keypad is hidden, the tap goes straight back to the last CalcTape keypad. To put a different layout into the active segment, long-press the same button: that opens the layout picker, in every edition from version 7.1. The same picker sits in Settings → Keyboard as three separate entries, one per segment. The swipe can be switched off under Settings → Keyboard → Switch keyboards by swipe.

Every segment can take every layout. Besides the three defaults the picker offers Standard [4x5], Standard [4x6], India [4x6] (with 00 and 000 in place of x² and √, for amounts in lakh and crore), Memory keys [6x4], left-handed variants of Standard [4x5] and of both Memory layouts, and Text navigation in [4x3] and [5x3]. Layouts are sorted by name and carry a prefix: [SYS] for the built-in ones, [USR] for a layout you saved yourself.

K1: the calculator keypad

Numbers 0–9, decimal separator, the four basic operators, %, = ↵ (close block, draw subtotal), AC (clear document, undoable), ⌫, the four memory keys and a user key, Customize this key, which explains how to put your own entry there (section 4).

K2: the function keypad

Powers (x², x³, xⁿ), root (√), reciprocal (1/x), the sign key +/-, the four tax keys (see User keys below) and a key that hides the keypad.

NAV: text and navigation

Cursor keys, line start/end, document start/end, selection, Cut / Copy / Paste, Undo / Redo, backspace and Enter, for editing without leaving the keypad.

Memory keys

The four keys come with the Memory keys layouts; in the default setup they sit in K1, spread over the top two rows next to AC and the backspace key.

Each of the three keys carries a small second line, and they show two different things: M+ and M− name the value they would apply - the one taken from the line the cursor sits in - while MR shows what is in memory. A key with nothing to offer stays dimmed, so on a fresh document M+ and M− are live as soon as the cursor sits on a value, and MR lights up once you have put something into memory. After M+ or M− a short message shows the new content (MR = …). The memory belongs to the app, not to a document: it stays when you switch documents and is cleared by MC or when Android ends the app.

By default M+ and M− take the value of the line the cursor sits in; on a line without a value of its own, such as the fresh line below a finished block, they take the block total. Settings → Calculation → M+/M- uses result makes them use the block result on every line.

User keys (+TAX)

The default K2 layout holds four user keys for taxes. Their captions and rates come from the tax table of your country, which CalcTape takes from the mobile network, the SIM card or the device language: in Germany, for example, +MwSt (19%) / -MwSt (19%) and the reduced rate +Ermäßigt (7%) / -Ermäßigt (7%); in the USA +Sales Tax (8.5%) / -Sales Tax (8.5%) and two tip keys. The plus keys add the tax, the minus keys take it out of a gross amount. Each key inserts a pre-configured calculation step and can be freely reconfigured (next section).

Tip: Accidentally pressed AC? Use Undo (the arrow in the result bar, or on the NAV keypad) to restore the previous content.

4. Customizing keys (Pro)

The Pro edition lets you customize every key on every keyboard.

Entering edit mode

Open the menu (⋮ at the top right) → Edit keyboard; the entry is there in every edition. The tape dims and a banner appears: "Tap a key to edit". Tap any key. Done ✓ in the banner ends edit mode.

The first change to a built-in layout saves a copy of it, named after the layout plus date and time. The copy becomes the layout of that segment and appears among your own layouts in the picker, where a long-press renames or deletes it.

Fields in the dialog

The editor has three tabs:

User buttons can also be created, deleted, and assigned to any key. In the Free edition the editor opens for user buttons only, and there only the User tab is free: System and Layout carry the Pro diamond ◊ and lead to the upgrade dialog. Free can edit the preset buttons (the tax keys and Customize this key), and Delete resets them to their defaults; creating user buttons and editing or deleting your own is Pro.

5. Documents

CalcTape stores each tape as a .calc document. The Free edition works with a single document, the Worksheet; other documents already on the device are greyed out in the list and open read-only. Pro manages an unlimited number of documents.

• Open the drawer: swipe to the right across the tape or tap ☰. In the landscape arrangements Keyboard right and Document-editor-keyboard the list sits next to the tape, and ☰ shows or hides it.
• Create (Pro): tap the + button, enter a name. The document opens immediately and is saved automatically.
• Context menu (Pro): long-press a document for Open, Delete, Rename, Duplicate and Export. The Worksheet cannot be renamed or deleted. Export saves the .calc file to a place you pick.
• Import (Pro): Import documents in the drawer takes one or more .calc files; a single one opens right away. A .calc file opened from another app is copied into CalcTape in Pro; in Free the Worksheet opens with a note on the upgrade.
• Auto-save: CalcTape saves by itself (section 7); there is no save button.
• Sort order: by date or name, ascending or descending (Settings → Documents). Newest first out of the box; the Worksheet always stays on top.

6. Sharing, printing, exporting

The menu (⋮) offers Share, a Pro feature; in Free it carries the diamond ◊ and leads to the upgrade dialog. Pick what to include:

• Text only: the tape content as plain text.
• CalcTape document: the .calc file itself, openable by other CalcTape users on any platform.
• HTML document: a styled page that any browser can render.
• TXT document: the plain text as a .txt file.

You can pick more than one, and CalcTape remembers your choice for next time; it then opens the system share sheet. With an email client and "Text only", the calculation appears in the message body; additional formats become attachments.

Print (Pro) opens Android's standard print dialog, so you can print or save as PDF. The printout shows the tape in print colours, dark on white whatever the theme, with the date, the time and the document name at the top.

Temporary export files live in app-private storage under …/files/export_tmp/ and are cleared before the next share. They exist only as the source for the content:// link the receiving app reads, so they never show up in a file manager, and uninstalling CalcTape removes them.

7. Saving and backup

Automatic saving

CalcTape saves your documents by itself in the app's private storage: every minute while you work, and whenever you leave the app, switch documents, share or back up. Closing the app or switching documents always preserves the latest state.

Every save writes a temporary file first and only then renames it over the old one, so an interrupted save cannot leave you with an empty or half-written document, and a save that fails says so instead of failing quietly. The message names the file that holds the newest version.

Backup and restore (Pro)

In the document drawer, expand Backup / Restore. Backup opens a dialog with four checkboxes, all ticked to begin with; Restore first asks for the ZIP archive and then shows the same checkboxes:

• Backup creates a single ZIP archive (CalcTape-YYYYMMDDHHMM.zip) in a location you choose, so the archives of one day sort in the order you made them.
• Restore ticks only the boxes the archive holds something for; the others stay greyed out. A document with the same name as one on the device replaces it, all others stay. Keyboard layouts and buttons replace your whole set of custom layouts and buttons, and settings replace what is currently set. After a restore the app restarts, following a short countdown.

A backup is meant to travel between phones, so three things are deliberately left out of a restore and keep their local values: the Pro licence, the device identifier it is derived from, and the state of the trial. Restoring a backup from another device therefore never affects your edition. Left out of the archive too is everything that only describes what has already happened on this device: the counters behind the review prompt, the feature hints and the trial offer.

Create a backup before switching phones, before a major Android upgrade, and as a regular safeguard.

8. Interface overview

The app is divided into the following areas:

The two icons between the document title and the edition marker belong to the Modern design and are missing in Classic. The sun/moon icon switches between light and dark; it always shows the state a tap would produce and starts from what you actually see, so from System default it goes to the opposite of the current brightness. The theme button shows the palette of the current theme and opens the palette tiles; in landscape it also names the palette. It can be switched off in Settings → Appearance once you have bought Pro, while the sun/moon icon stays either way.

The edition marker reads [ ◊ Free ], [ EVAL ] with a clock during the trial, or [ Pro ]. A tap on it opens the upgrade screen in Free, the state of the trial in Eval and the About screen in Pro. With Pro bought, it can be hidden in Settings → Appearance.

The result bar

The result bar sits directly above the keyboard and always shows the current result of the calculation at the cursor. Tap the number or the copy icon to put just that number on the clipboard, or long-press the copy icon for the grand total of the whole document; both work in every edition. The bar also holds the segment button (K1 / K2 / Nav, see section 3), the ABC key that switches to the system keyboard, a keyboard icon that hides and shows the keypad, and the arrows for Undo and Redo. While the system keyboard is open, the "+" button stands in place of ABC and, while it is on, types operators as text (see Comments).

Four gestures work anywhere along the bar:

The quick swipe and the slow drag differ in time, not in distance: hold for a moment before you move and you are resizing.

Adapting to screen size

• Portrait: tape on top, keyboard at the bottom; the keyboard takes 20 % to 80 % of the screen (drag the result bar slowly to adjust).
• Landscape: one of three arrangements in Settings → Keyboard → Landscape layouts: Keyboard bottom, Keyboard right (the default), or Document-editor-keyboard, which puts the document list, the editor and the keyboard side by side. In the two side-by-side arrangements, drag the divider between tape and keyboard to resize; with Keyboard bottom, use Keyboard size (landscape) in the settings.
• Tablets follow the same rule: held upright they show the portrait view, turned sideways the landscape arrangement.

9. The menu

The overflow menu (⋮ at the top right) contains the document commands:

The first three entries appear according to your edition and vanish once you own Pro. The diamond ◊ marks what needs Pro; plain copying of the calculation and of the grand total is free in every edition.

The main menu (☰ at the top left) opens the document drawer (section 5).

10. Settings

Open ☰ → Settings. The groups follow the order on screen:

Cursor when opening a document

Three choices decide where the cursor sits once a document has been read:

The choice is written into the document, so the tape opens in the same place in every CalcTape you carry it to.

Rounding

Four modes decide how the configured number of decimals (2 out of the box) is applied; the default is Round results:

11. Design, themes and languages

Since version 7.1 the look is described by three settings instead of one:

• Design decides which world you are in. Classic (like version 7.0) is the appearance of CalcTape 7.0, unchanged. Modern brings the colour palettes, the tile picker, and the theme button and sun/moon icon in the title bar.
• Themes picks the theme within that design.
• Light/dark mode picks brightness: Light, Dark or System default.

Existing installations stay on Classic when they update, so nothing changes underfoot. New installations start in Modern. If you updated and would like to see the new design, CalcTape offers it once, at a quiet moment, and a single tap takes you back to the familiar look at any time.

The themes of the Classic design

The two classic themes bring their own brightness, so the Light/dark mode setting has no effect while one of them is active.

The palettes of the Modern design

Nine palettes are bundled, each with a matching light and dark mode. All of them are free, in every edition.

Pick a palette in Settings → Appearance → Themes, where every entry shows a miniature of the app in that palette. With Theme button in the title bar switched on, the toolbar shows the palette of the current theme; tapping it opens the same tiles and applies your choice immediately - a tap on a tile takes effect at once, there is no OK to confirm.

The row ‹ Classic (like version 7.0) at the top of that panel is the way back to the previous design, kept above the palettes so it stays in view.

Languages

CalcTape is fully translated into 17 languages: English, German, French, Spanish, Italian, Portuguese (Portugal), Portuguese (Brazil), Russian, Swedish, Turkish, Ukrainian, Indonesian, Bengali, Hindi, Korean, Japanese and Chinese (simplified). The language follows the system by default and can be overridden in Settings → General → Language; on Android 13 and later the choice is stored as a per-app language.

12. Editions: Free, Eval, Pro

Eval is a one-time trial of the full Pro edition, lasting 10 days. Every surface that offers it starts the trial with a single tap and then confirms the exact end date: the entry Try Pro for 10 days in the overflow menu, the upgrade screen, the release notes, the offer that appears at a quiet moment in the Free edition, and the dialog you get when you reach for a Pro feature; in that last case, repeat the action once the trial runs. Afterwards the app reverts to Free; documents other than the Worksheet remain readable but become read-only until you upgrade.

Upgrading: tap the edition marker [ ◊ Free ] in the toolbar or Upgrade to Pro in the overflow menu. The upgrade screen lists what Pro adds and shows the price; Upgrade opens the Google Play purchase dialog.

Pro is bound to your Google account, not to the device. CalcTape asks Google Play on every start and whenever you return to the app; if it finds a purchase this device does not know about yet, Pro unlocks silently. Moving to a new phone with the same account therefore needs nothing from you. The check never takes an entitlement away: being offline looks the same as owning nothing, so an unanswered query leaves your Pro edition alone. Restore purchases in the overflow menu runs the same check on demand; if Google Play knows no purchase for the account, a message says so.

When a purchase does not complete

Two answers from Google Play do not unlock Pro, and both say so in a dialog. Payment still pending: some payment methods confirm later, Google Play completes the purchase on its own, and Pro unlocks the next time you open the app; nothing is required from you. The purchase could not be verified: CalcTape checks the signature Google Play returns and refuses a purchase that fails it; if you were charged anyway, write to Support with your payment confirmation.

Pro in Ukraine

In Ukraine, the Pro features are available without a purchase, a small gesture on our part. CalcTape recognises the situation from a Ukrainian SIM card, from the mobile network the device is registered in, or, when no network can be determined, from the time zone set on the device. No permission is needed and no location is stored. The title bar then carries the Ukrainian flag in place of the edition marker, and a short note appears once. The state is worked out afresh at every app start, so it ends by itself when the conditions no longer hold. A Ukrainian SIM card keeps it on abroad as well, so that it also reaches people who had to leave the country.

13. Troubleshooting & limits

There is no in-document search; for very long tapes, scroll or export the text. If a line contains an error, the affected result shows an error marker and the description appears when the cursor is on the line.

14. Privacy

CalcTape stores your documents and settings on your device, in app-private storage that other apps cannot read:

Uninstalling CalcTape removes all of it from the device; the backup in section 7 gives you a portable copy. If Android's own backup to your Google account is switched on, Android includes CalcTape's documents and settings in it and puts them back when you reinstall the app or set up a new phone. CalcTape itself sends nothing: nothing analytic is collected, no telemetry and nothing about your calculations. The Google Play billing client checks the Pro license against your Google account; that is a Google-side mechanism and does not transmit document content. When CalcTape asks for a rating, it uses Google Play's own review dialog, and your rating goes to Google Play only.

The About screen lists the version of the shared calculation core and, under Open source licenses, the licence texts of third-party components.

When you contact Support, CalcTape pre-fills app version and edition, Android version, device manufacturer and model, and active keyboard app. All values are visible in the email composer and can be edited or removed before sending.

15. CalcTape for other platforms

CalcTape is also available for:

• Windows
• macOS
• iOS / iPhone
• CalcTape Web (in the browser, no installation)
• CalcTape for Business (Enterprise)

.calc files are portable: documents exported from Android can be opened and edited in every other CalcTape app, and vice versa. You can find all apps at calctape.com.