Free Online Calculator
Fast, accurate, responsive calculator.
About
This free online calculator runs entirely in your browser — no installation, no account, and no ads. It handles everyday arithmetic instantly: add, subtract, multiply, divide, and calculate percentages with a single click or keystroke. Whether you're splitting a bill, checking a discount, working out a tip, or doing quick homework maths, the calculator gives you an accurate result in under a second. It works on any device — phone, tablet, or desktop — and supports full keyboard input so you never have to reach for the mouse. Results are computed with floating-point precision and automatically rounded to remove display artifacts, so 0.1 + 0.2 shows 0.3, not 0.30000000000000004.
Features
- Addition, subtraction, multiplication, and division
- Percentage calculations (e.g. 20% of 150)
- Decimal number support
- Full keyboard input — digits, operators, Enter, Backspace, Escape
- Error handling for invalid expressions and division by zero
- Mobile-friendly touch interface
- Zero data stored — all calculations run locally in your browser
FAQ
Is this calculator free to use?
Yes, completely free. There is no sign-up, no account, and no cost. Open the page and start calculating immediately.
Does this calculator work on mobile?
Yes. The calculator is fully responsive and optimized for phones, tablets, and desktops. Buttons are sized for touch input and the layout adjusts automatically to your screen size.
Can I use my keyboard to type calculations?
Yes. Type digits and operators (+ - * /) directly from your keyboard. Press Enter or = to calculate, Backspace to delete the last character, and Escape to clear everything.
How do I calculate a percentage?
Type the number followed by the % key. For example, to find 20% of 150, type 150 * 20% and press =. The calculator converts the percentage automatically before evaluating.
What is the order of operations this calculator uses?
The calculator follows standard mathematical order of operations (PEMDAS/BODMAS): parentheses first, then multiplication and division left to right, then addition and subtraction left to right.
Does the calculator support decimal numbers?
Yes. Press the decimal point (.) button or key at any time to enter a decimal number. The calculator handles decimal addition, subtraction, multiplication, and division accurately.
What happens if I divide by zero?
The calculator will display an error message instead of crashing or showing Infinity. Simply press C to clear and start a new calculation.
Does the calculator save my calculation history?
No data is stored or sent anywhere. All calculations run entirely in your browser. Refreshing the page resets the display.