Expression calculator
Handle quick arithmetic with deterministic parsing and exact formatting. This workspace keeps parsing explicit, uses exact fraction arithmetic internally, and shows when a decimal is only an approximation.
Live workspace
Enter numbers, parentheses, and the operators + - * /. Calculations run only when you submit, so the input never jumps while you are typing.
Quick guide
Build the expression first, then submit when you are ready. The parser keeps the normalized form visible so you can confirm exactly what was read.
Starter patterns
Load a sample expression to test fractions, grouped arithmetic, or a pricing-style formula.
Primary result
Evaluated expression
31.25
Result profile
Exact value
31.25
Decimal view
Exact decimal
Value type
Terminating decimal
No approximation was needed.
Normalized expression
This is the exact expression shape the parser evaluated after spacing and grouping were normalized.
12.5 * (4 - 1.5)