About the Calculator
This basic calculator handles addition, subtraction, multiplication, division, percentages and sign changes. It follows the standard order of operations, so 2 + 3 × 4 = 14, and it cleans up floating-point noise so that 0.1 + 0.2 shows 0.3 instead of 0.30000000000000004.
On a computer you can type with the number keys and use Enter, Backspace and Esc. Tap any entry in the history to bring its result back and keep calculating.
How to use
- Tap the number buttons (or type digits) and choose an operator: + − × ÷.
- Press = or Enter to see the result. Press an operator right away to keep calculating with it.
- ⌫ (Backspace) deletes one digit, AC (Esc) clears everything.
- Tap an entry in the history to reuse its result, or use Copy to copy the current result.
Keyboard shortcuts
| Key | Action |
|---|---|
| 0–9, . | Digits and decimal point |
| + − * / | Add, subtract, multiply, divide (x also multiplies) |
| Enter or = | Show the result |
| Backspace | Delete the last digit |
| Esc or Delete | Clear everything (AC) |
| % | Percent |
How the % key works
It works like the calculator on your phone:
- 200 + 10% → adds 10% of 200 (20) = 220 (adding tax or a tip)
- 200 − 10% → subtracts 20 = 180 (a 10% discount)
- 50 × 10% → 50 × 0.1 = 5
- A number followed by % alone is divided by 100 (10% → 0.1)
Order of operations and rounding
Multiplication and division are done before addition and subtraction (PEMDAS). Some desk calculators work strictly left to right and would show 20 for 2 + 3 × 4; this calculator shows the mathematically correct 14.
Computers store decimals in binary, which causes tiny errors such as 0.1 + 0.2 = 0.30000000000000004. Results are rounded to 12 significant digits so these errors don’t show.
FAQ
Where is my calculation history stored?
Your last 50 calculations are saved only in this browser. Nothing is sent to a server, and you can delete the history at any time with “Clear history”.
Why is 2 + 3 × 4 equal to 14 and not 20?
Because multiplication comes before addition in the order of operations: 3 × 4 = 12 first, then 2 + 12 = 14.
How are very large or very small numbers shown?
You can enter up to 15 digits. Results of a quadrillion (10^15) or more, or extremely small decimals, are shown in scientific notation such as 1.5e18.
What happens if I divide by zero?
You’ll see “Cannot divide by zero”. Press any number to start a new calculation.