Basic arithmetic
A Fast Calculator for Everyday Arithmetic
A simple calculator should do one job well: make basic arithmetic quick, predictable, and easy to check. This page is focused on the operations people use constantly: addition, subtraction, multiplication, division, percentages, and decimal values.
Use it when you need a quick total, a difference between two numbers, a unit price, a shared cost, or a percentage adjustment. The calculator is intentionally direct, so you do not have to think in formulas or switch to a spreadsheet for small tasks.
Decimal precision matters even in basic math. JavaScript numbers can produce unexpected floating-point results for values like money or measurements, so this calculator uses decimal arithmetic under the hood for cleaner results.
The best basic calculator interface is boring in the right ways: visible numbers, obvious operators, a clear result, and a reset button when you want to start again. That keeps the page useful for repeat calculations instead of turning a simple task into a bloated tool.