Basic Calculator
Updating live: standard four-function arithmetic with operator precedence. Need powers or roots? Try the scientific calculator. Want percentages? Use percentage.
What Your Result Means
- Display result: The outcome of the arithmetic operation you entered. This calculator follows standard left-to-right evaluation — it processes each operation as you press equals, without automatic order-of-operations (PEMDAS).
- Chaining operations: You can chain calculations by pressing an operator after getting a result. The previous answer becomes the first operand of the next operation.
- Division by zero: If you divide by zero, the display shows "Error." Clear and start a new calculation.
How This Calculator Works
Type a number, press an operator (+, −, ×, ÷), type a second number, and press equals. The tool performs the arithmetic and displays the result. It handles one operation at a time in the order you enter them — like a handheld pocket calculator. Use C to clear everything, or the backspace key to delete the last digit. Keyboard input is fully supported.
Quick Questions
Does this follow order of operations (PEMDAS)?
No — this is a simple sequential calculator, like a basic handheld model. It evaluates each operation as you press equals or chain another operator. For expressions that need PEMDAS, break them into steps or use a scientific calculator.
Can I use my keyboard?
Yes. Number keys, +, -, *, and / all work. Press Enter for equals and Escape or Delete to clear. Backspace removes the last digit.
What's the maximum number it can handle?
This calculator uses JavaScript's standard number type, which safely handles integers up to about 9 quadrillion and decimals to roughly 15–17 significant digits. Beyond that, results may lose precision.
Why does 0.1 + 0.2 show 0.30000000000000004?
This is a well-known floating-point rounding artifact in all computers, not a bug. Binary representation can't express some decimal fractions exactly. For everyday math the difference is negligible.
Sources
- Wikipedia — Arithmetic (four basic operations)
- MDN — JavaScript Number (precision and limits of JavaScript numbers)
Method & review
Estimate only. Results reflect your inputs and standard formulas. Double-check important decisions independently.