Basic Calculator
Free online basic calculator with a keypad UI. Add, subtract, multiply, divide, percent, negate. Keyboard support, live results. 100% browser-based, no signup, unlimited.
Keyboard: digits, +, -, *, /, Enter (=), Esc (clear), Backspace (delete)
Full Keypad
Standard 4×5 calculator layout: digits 0-9, +, −, ×, ÷, %, ±, decimal, clear, equals. Live result preview as you type.
Keyboard Support
Type numbers and operators directly. Enter = equals, Esc = clear, Backspace deletes the last char. Works on any keyboard, any device.
100% Private
Every calculation runs entirely in your browser. No network request, no signup, no server. Your math never leaves your device.
Strict & Safe
The expression is sanitized to digits and operators only — no template literals, no property access. Chained calculations continue from the previous result.
Is this basic calculator free?
Yes, completely free with no signup, no daily limit, and no ads inside the tool. Use it as often as you need, on any device.
Can I use my keyboard?
Yes. Type digits and +, -, *, / directly. Press Enter (or =) for equals, Esc for clear, Backspace to delete the last character. The calculator intercepts these keys globally so you never need to click.
How does the % button work?
The percent button converts the trailing number to its percentage value (divides by 100). So pressing 5 then % turns it into 0.05, ready to use in further calculations. It never uses JavaScript's modulo operator.
What does ± do?
It negates the trailing number by wrapping it as (-N). So an entry like 5 becomes (-5). You can negate any operand in your expression, not just the first one.
What happens after I press =?
The result becomes the new expression. If you press a digit, the calculator starts fresh; if you press an operator, it chains from the result (e.g. = then × then 5 multiplies the previous result by 5).
Ready to use the Basic Calculator?
Free, no signup, no watermark. 100% browser-based. Your data never leaves your device.
Open the tool