Basic Calculator
Fast, free online calculator. Tap buttons or use your keyboard to add, subtract, multiply and divide.
How to use this calculator
Click the on-screen buttons or use your keyboard to enter numbers and operations. Press Enter or = to calculate, Escape or C to clear, and Backspace to delete the last digit. The top line shows your current expression so you can verify it before computing.
Frequently asked questions
Is this calculator free to use?
Yes, completely free with no sign-up required. Open the page and start calculating immediately. It works on any device — desktop, tablet, or phone.
Does it work with keyboard input?
Yes. All digit keys (0–9), operators (+ - * /), decimal point, Enter (equals), Escape (clear), and Backspace are fully supported. You can use the number pad or the main keyboard row.
What does the % button do?
The % button divides the current number by 100, converting it to a decimal percentage. For example, entering 75 then pressing % gives 0.75. Useful for percentage-off discount calculations: 500 − 20% can be computed as 500 × (1 − 20/100) = 400.
What does +/- do?
The +/- button flips the sign of the current number between positive and negative. For example, if the display shows 42, pressing +/- changes it to −42. This is handy for entering negative starting values without using the subtraction operator.
How is the order of operations handled?
This is a simple arithmetic calculator that evaluates operations in the order you enter them (left to right, one operation at a time), matching how a standard pocket calculator works. For complex expressions with mixed operator precedence, use the scientific calculator instead.