OfficeCalc: Paper Tape Calc

OfficeCalc is a 10-key desk calculator for people who need to see their working, not just the answer.

Every entry, result and adjustment lands on a running paper tape you can scroll back, correct, annotate and export. It is built for invoices, quotes, stock counts, cashing up and VAT, where "what did I actually add up?" matters more than the total.

WHAT MAKES IT DIFFERENT

A real tape, not a history list. Every figure gets its own line with the operator beside it, exactly like a printing calculator, and the total is worked out from the column. Multiplication and division resolve first and show their result in brackets, so you can see where a figure came from.

Subtotal and Grand Total, the two keys a printing calculator is not one without. Subtotal prints the running figure without ending the chain, so you can check yourself halfway down a column and carry on. Grand Total sums every result since the last clear, for a stack of separate calculations.

Tapes are sessions. Name one, close the app, come back tomorrow and carry on from its last figure. Hold C to start a fresh tape without losing the one you were on.

Label your lines. Tap any row to caption it (Supplies, Invoice 214, Till 2), so a tape still makes sense a week later, and labels come through as their own CSV column.

Change any figure, any time. Tap a line and correct it, or delete it, and everything below recalculates on its own. No stored answers to go stale, no retyping the column because one number was wrong. Most tape calculators cannot do this.

THE KEYPAD

Big keys: Compact, Normal, Large or XL. Pro adds Tiny and drag-to-size.
Double-zero and triple-zero shortcuts for round figures.
A scrollable helper bar for Tax+, Tax-, MU, percent, subtotal, grand total, plus-minus and the four memory keys.
Haptic feedback and a press tint on every key.
Copy the display to the clipboard, or paste a figure in.

TAX, PERCENTAGES AND MARKUP

Keep several tax rates and switch without going into settings. It ships with 20,12,5 and 0 for UK VAT; set your own, then long-press Tax+ or Tax- to change the rate. Tax+ adds it, Tax- takes it back out, and both write a tape row showing the rate, the amount and the result.

The percent key behaves the way a desk calculator should: "100 + 5%" gives 105, "200 x 20%" gives 40.

MU prices a job from its cost at your margin, and runs backwards on the same key: "150 - 130 MU" reports 13.33%, the margin on the selling price. Long-press MU to change the rate.

Arithmetic runs on decimal maths, not floating point, so money does not drift. Fix the decimal places or let it decide.

SHARING AND BACKUP

Share a tape as plain text, as a multi-page PDF, or as a CSV that opens straight in a spreadsheet, entries and results in separate columns.
Export a full backup of every tape and your settings to a file you choose, optionally password-protected.

YOUR DATA STAYS ON YOUR DEVICE

No account. No sign-in. No analytics. No ads. No tracking.

Your calculations are stored on your own phone and are never sent anywhere. Automatic Google Drive backup is off for this app on purpose, so the app's own export is the only way to move your tapes to a new phone. Make one before you change devices.

The app includes Google Play Billing for the optional one-time Pro unlock, and that is the only reason it asks for internet access. The calculator never uses the network.

FREE, AND OPTIONAL PRO

The calculator is free and always will be. The tape, sessions, labels, subtotal, grand total, tax rates, percentages, memory, keypad sizes Compact to XL, plain-text and CSV export, and backup are all free, with nothing held back.

OfficeCalc Pro is a single one-time purchase, not a subscription. It unlocks PDF export (a formatted, multi-page document), the extra colour palettes, AMOLED true black, and smaller keypad sizes (Tiny, or drag to any size). Nothing you need in order to do a calculation, or to get your own data out, sits behind it.

Questions or ideas: [email protected]