Math and measurement tools
Fraction Calculator
Add, subtract, multiply or divide fractions and mixed numbers. Get an exact simplified fraction, mixed number, decimal estimate and the calculation steps.
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How to use this tool
1. Enter a whole number, a fraction such as 3/4, or a mixed number such as 1 1/2. A leading minus applies to the entire value.
2. Choose addition, subtraction, multiplication or division, then enter the second value. Denominators must be positive.
3. Calculate to see the exact simplified result and mixed number, plus a rounded decimal and the arithmetic used.
How fraction arithmetic works
Addition and subtraction use a common denominator. Multiplication multiplies the numerators and denominators. Division multiplies by the reciprocal of the second value. The numerator and denominator are then divided by their greatest common factor.
Worked example
1/2 + 1/3 = (1 × 3 + 1 × 2) / (2 × 3) = 5/6. Its decimal is approximately 0.833333333333. Multiplying -1 1/2 by 2/3 gives exactly -1.
Questions and assumptions
Input format and limits
Use integers, a/b or mixed numbers separated by one or more spaces. Each whole-number part, numerator and denominator is limited to 1,000,000,000. Mixed numbers need a proper fractional part. Decimal notation, thousands separators and negative denominators are not accepted.
Exact results and decimal approximations
Fraction and mixed-number results use exact integer arithmetic. Decimal results use up to twelve significant digits and may be approximate. A negative mixed result such as −1 3/8 means the negative of the entire 1 3/8. Division by zero has no result.
Sources and further reading
Built and maintained by Custom Logic. Page updated .