Current for 2026•As of: July 2026

Calculator free online calculator.

All four basic operations, percentages and sign change – directly in your browser

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Calculator

Standard calculator with all four basic operations, percentages and sign change.

0

Keyboard: digits, decimal, + − * / · Enter = result · Backspace = delete digit · Esc = AC

Calculation tape

No calculations yet. Results with "=" land here – permanent, labelable and reusable with a click.

Need parentheses, powers or sin/cos/tan? Scientific Calculator

Online calculator: basics and operation

All the functions of a classic calculator in your browser

A calculator is the most widely used calculation tool in the world. Our online calculator offers all the functions of a classic desktop calculator: the four basic operations addition (+), subtraction (−), multiplication (×) and division (÷), plus the percent key (%) and the sign change (±). It runs entirely in the browser – no app, no sign-up, free of charge.

The operation follows the principle of classic calculators: you enter the first number, press an operation key, enter the second number and confirm with "=". The result appears immediately. Multiple operations can be chained directly one after another – the calculator works sequentially from left to right, just like a school calculator. If you need order of operations, parentheses or functions like sin, cos and log, use the scientific calculator.

For common use cases such as percentage calculations, the % key offers a handy shortcut: with an active operation, it calculates the percentage value relative to the first number. Entering "200 + 10%" gives 220, because 10% of 200 = 20 is added to the starting value. Without a preceding operation, % divides the displayed value by 100.

Tips & keyboard shortcuts

Work faster with the online calculator

The keyboard operation makes the calculator especially efficient on desktop. Digits, decimal point and all four arithmetic operators (+ − * /) are recognized directly. Enter or = gives the result, Escape resets everything (AC) and Backspace deletes the current entry (C), without losing the ongoing calculation.

The distinction between C and AC (All Clear) is particularly useful: if you made a typo in the second number of a calculation, C only clears this entry – the first number and the operator remain. Only AC resets the entire calculation. The button automatically shows "AC" when no intermediate value is stored, and switches to "C" as soon as a calculation is in progress.

When entering long numbers, the calculator limits the number of digits to avoid rounding errors. Internally it calculates with 10 significant digits and automatically strips trailing zeros, so e.g. 0.1 + 0.2 is correctly displayed as 0.3 – not as 0.30000000000000004, as can happen with naive floating-point arithmetic.

Frequently asked questions about the online calculator

Operation, percentage calculations and special features

First press the starting number, then the desired operation (+, −, ×, ÷), then the percentage value and finally the % key. For "200 + 10%" the calculator computes 10% of 200 (= 20) and adds it – the result is 220. Without a preceding operation, the % key simply divides the number by 100: 50% gives 0.5.

Yes. The number keys 0–9 and the decimal key work directly. For operators use + (plus), − (minus), * (times) and / (divided by). Enter or = calculates the result, Backspace deletes the last digit, Delete clears the current number (C) and Escape resets the calculator (AC).

C (Clear) only deletes the currently displayed number but keeps an ongoing operation in memory. This lets you correct a mistyped number without having to restart the whole calculation. AC (All Clear) resets the entire calculator and clears all stored values.

Division by zero is mathematically undefined. In this case, the calculator displays "Error". Press C or AC to clear the error and start a new calculation.

No – like a classic pocket calculator, evaluation is strictly sequential from left to right. The input 5 × 3 − 2 therefore results in 13 (first 5 × 3 = 15, then 15 − 2 = 13). If you need order-of-operations calculations, compute the sub-steps separately.

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