About the calculator

One tape, eleven calculators.

Here are eleven calculators that print to one running paper tape, like an adding machine’s receipt. Type with the keyboard or press the keys on screen; press Enter and the calculation prints to the tape with its time, the calculator it came from and the result. Every number on the tape can be reused in the calculation you are working on, explained, copied, printed or exported.

It runs entirely in this page: nothing you enter is sent anywhere, and the tape, your settings and your currency rates are kept in this browser. The same calculator has its own site at calc.llc.

The eleven

A calculator for each kind of sum.

Standard — arithmetic with precedence and parentheses, percent, square root, square and reciprocal keys, and memory (MC, MR, M+, M−, MS).
Scientific — degrees or radians; sine, cosine and tangent with their inverses and hyperbolics; ln, log and log₂; powers and roots; factorial; π, e and Ans.
Programmer — hexadecimal, decimal, octal and binary side by side, 8, 16, 32 or 64-bit words in two’s complement, AND, OR, XOR, NOT, NAND, NOR and shifts, and a bit grid.
Unit Converter — length, mass, temperature, volume, area, speed, time and data, with the value in every unit of the category at once.
Currency — 31 currencies against a rate table you edit. The rates it starts with are labelled example rates, not today’s.
Loan & Mortgage — monthly payment, total interest, total paid and payoff date, what an extra monthly payment saves, and the amortization schedule year by year; the mortgage side adds down payment, property tax, insurance and PMI.
Percentage & Tip — tip and split a bill, X% of Y, percent change from A to B, A as a percentage of B, and Y plus or minus X%.
Date Calculator — the span between two dates in days, weeks and years, months and days, business days Monday to Friday (public holidays are not taken out), and adding or subtracting days, weeks, months or years.
Age Calculator — exact age in years, months and days as of any date, total months, weeks and days, the weekday you were born and the days to your next birthday.
BMI & Health — metric or imperial BMI with its WHO category, BMR by the Mifflin–St Jeor equation and daily calories by activity level. Estimates, not medical advice.
Statistics — a dataset built on the keypad or pasted in; count, sum, mean, median, mode, minimum, maximum, range, variance, standard deviation, quartiles and IQR as a sample or a population, with a histogram.

Ctrl+1 to Ctrl+9 and Ctrl+0 switch to the first ten calculators, and Ctrl+[ and Ctrl+] step to the previous and next one (Alt works the same way).

The tape

Every result, printed and explained.

New lines feed in at the top of the roll with the time, the calculator, the expression and the result. Click a number to reuse it. Right-click it, or press and hold on a touch screen, and a card explains what that number is and how it was worked out, with copy, reuse, delete, share and export beside it. History can be switched off, the tape can be printed on its own or cleared, and a cleared tape can be brought back with Undo.

Exports

Out as text, a table, a picture or a receipt.

Copy the tape as plain text or as a Markdown table, or one line’s value or expression.
CSV of the history, with timestamp, calculator, expression and result columns.
JSON backup of everything the calculator keeps, and import to restore it.
PNG: one calculation as a torn-receipt card, or the whole tape at twice the resolution, drawn in the theme you are using.
PDF: the tape as a receipt with page numbers and a running total, one line on its own, the loan amortization schedule, or a statistics report.
Share through the device’s share sheet where the browser has one.

Copies of the tape and its CSV, PNG and PDF exports can be limited to today, the last 50 lines or everything; the JSON backup always holds everything.