Tape Calculator Online

An online adding machine that records every step on a printable receipt tape. Enter numbers with +/−/×/÷, review your full calculation history, edit or delete any row, then export a PDF receipt — works entirely in your browser, nothing is sent anywhere.

Your calculation tape will appear here.

How it works

This tool works exactly like a physical paper-tape adding machine: every number and operator you enter is logged as a new line on the tape. You can see the running subtotal after each step, delete or correct any entry, and print the entire tape as a PDF when you are done.

Enter a number Type digits using the keypad or your keyboard. The display shows the current entry.

Press an operator + adds, − subtracts, × multiplies, ÷ divides the entry to the running total. % converts the entry to a percentage of the current total.

↵ confirms & continues Press Enter / ↵ to add the current display value to the tape and keep the total running. Use this for a pure addition list.

Delete any line Click × on any tape row to remove it. The totals below it recalculate automatically.

Example: Start with 100 → press + → type 45.50 → press ↵ → subtotal = 145.50. Then press × → type 1.08 → press ↵ → final = 157.14.

Frequently asked questions

What is a tape calculator, and why use one instead of a regular calculator?: A tape (or adding-machine) calculator records every step of a calculation as a scrollable, printable list — just like the paper roll that spits out of a desktop adding machine. A regular calculator shows only the current number. With a tape calculator you can spot typos instantly, share a readable audit trail with a client or colleague, and re-check totals without re-keying everything. It is especially useful for expense reports, receipts, invoices, and bookkeeping.
How does the % key work on this adding machine?: Pressing % converts the number you just typed into a percentage of the current running total and applies it with the active operator. For example: if your total is 200, and you press + → type 10 → press % → then ↵, the calculator adds 10% of 200 = 20, giving a new total of 220. This matches the behaviour of classic office adding machines like the Casio DR series.
Can I edit or delete a line after I have already entered it?: Yes. Every line on the tape has a small × button on the right. Click it to remove that entry; all subsequent subtotals automatically recalculate. You cannot currently edit the value of an existing line in place — instead, delete the incorrect line and re-enter it at the end of the tape. This mirrors how physical adding-machine tapes work (void and re-enter).
How do I print or save the receipt as a PDF?: Click Download PDF Receipt to generate a formatted receipt using pdf-lib (runs entirely in your browser — no data is uploaded). The PDF mimics a narrow thermal-printer receipt: operator, value, and running subtotal for each line, plus a bold grand total at the bottom. Alternatively, click Print to send the tape directly to your printer or to "Save as PDF" via your browser's print dialog.
Does this work on mobile, and can I use my keyboard?: Yes to both. On desktop, number keys (0–9), decimal point, operators (+, −, *, /), Enter, Backspace, and Escape all work directly from your keyboard. On mobile, use the on-screen keypad. The tape scrolls on all devices and the PDF download works on modern iOS and Android browsers.