A calculator with a paper tape. Every line you enter stays on screen, the answer updates as you type, and any earlier result is one tap from being reused.
Coming SoonFree and fully unlocked. No ads, no account, no tracking.
For iPhone running iOS 17 or later.
Prism Tape Calculator brings back the one thing desk calculators got right: the tape. Each calculation you commit is printed above the keys like an adding machine, the last few lines stay in view while you work, and tapping any of them drops that result into what you're typing. Underneath is a modern engine — full-expression editing with a live result, exact decimal math, percent that behaves, and a scientific keypad a tap away. Everything stays on your device.
A real tape — every line printed, always in view, tap to reuse.
Exact math — 0.1 + 0.2 = 0.3, and 200 + 15% = 230.
Data Not Collected — no ads, no account, no analytics.
Every calculation you commit is printed to the tape, newest at the bottom. The last few lines stay visible above the display, so you always have context for the number you're working on.
Drop an earlier result straight into what you're typing now. Open the full tape to scroll back through everything, swipe to delete a line, or clear it all. It's stored on your phone and waiting when you come back.
1,250 × (1 + 8.25%) stays on screen — not one number at a time. The result previews live under it before you press equals, so typos are caught before they cost you.
Decimal arithmetic means 0.1 + 0.2 = 0.3, exactly — money math without floating-point surprises. Thousands separators, sensible rounding, and scientific notation only when a number really needs it.
200 + 15% = 230. 50 − 10% = 45. 20 × 5% = 1. One consistent rule set, no mode switching, no surprises when the tip or the tax comes out.
Tap sci, or rotate to landscape, for parentheses, powers, roots, sin, cos, tan, ln, log, factorial, π and e. Degrees or radians. 2π and 3(4 + 1) mean what you expect.
Divide by zero, an unbalanced parenthesis, an invalid input — you're told what went wrong, not shown a mystery "Error". Backspace removes a whole function like sin( in one go.
The whole app is a few megabytes and opens instantly. There's no network at all — it works on a plane, in a basement, or with Wi‑Fi off. Big rounded keys, haptics, light and dark mode.
No analytics, no advertising SDKs, no third-party code, no subscription. Your tape never leaves your device. App Store privacy label: Data Not Collected.
Most calculator apps show one number at a time, forget what you typed the moment you press equals, and interrupt you with full-screen ads. Prism Tape Calculator does the opposite: the whole expression stays on screen, every result is kept on a tape you can tap back into, and there are no ads, no account, no subscription and no third-party code.
It also does arithmetic the way money expects — in decimal — so 0.1 + 0.2 is 0.3 and a percentage means what you meant.
Anyone adding up receipts, splitting a bill, working out a margin, checking a quote, or doing homework — anyone who has ever lost their place halfway through a long sum. If you've wanted a printing calculator in your pocket without the paper, this is it. Students get a real scientific keypad; everyone else gets a calculator that shows its work.
The app makes no network requests at all. There is no account, no analytics, no advertising SDK and no third-party code. Your tape is stored on your device in a small file that belongs to the app, and it is erased when you delete the app. Prism Data Group receives nothing.
Nothing leaves your device. Read the full privacy policy.
Questions, bug reports, or feedback about Prism Tape Calculator? Send us a note and we'll get back to you.