Fraction Calculator | Simplify, Mixed Number & Decimal

Use exact BigInt arithmetic for large integer fractions and show simplified improper, mixed-number, and 12-place decimal forms.

Focus mode

Fraction expression

Calculate two fractions with exact integer-based rational arithmetic.

First fraction

Numerator

Denominator

Operation

Second fraction

Numerator

Denominator

Exact fraction result

Simplified improper fraction: 5/6
Mixed number: 5/6
Decimal · Approximation: ≈ 0.833333333333

Fraction operations and simplification use exact BigInt integers. Decimal output is limited to 12 places and marked approximate when it does not terminate.

Key features

Adds, subtracts, multiplies, and divides two fractions.
Uses BigInt integers up to 256 digits instead of floating-point arithmetic, then reduces by the greatest common divisor.
Shows the result as a simplified improper fraction, mixed number, and decimal.
Cuts non-terminating decimal output at 12 places and labels it as approximate.

How to use

Enter integer numerators and nonzero denominators for both fractions.
Choose addition, subtraction, multiplication, or division.
Compare the exact fraction forms and the decimal approximation label.

Examples

Check fraction homework
Compare an arithmetic answer with its reduced fraction and mixed-number form.
Work with large integer ratios
Keep exact rational results beyond ordinary floating-point integer precision.

Privacy

Input integers and results exist only in browser memory and are not transmitted or stored.

Requirements

Numerators and denominators must be signed integers of at most 256 digits. Zero denominators and division by a zero-valued fraction are rejected.

Common questions

Is a decimal such as 1/3 exact?: The fraction is exact, but decimal output stops at 12 places and receives an approximation marker.
Can I enter a negative denominator?: Yes. Normalization moves its sign to the numerator so the resulting denominator is positive.