How to use this calculator
- Enter your own values in the labeled fields. Check the units and assumptions before comparing results. Only the fields needed for your selected calculation mode are shown.
- Your answer updates automatically. Review the calculation steps to see exactly how it was calculated.
- Copy, share, save, or download your result. Saved inputs stay on this device.
How the calculation works
Adding or subtracting fractions requires a common denominator. Multiplication uses the product of numerators over the product of denominators. Division multiplies the first fraction by the reciprocal of the second. The result is reduced by the greatest common divisor, with any sign kept in the numerator.
A worked example
1/2 + 1/3 = (3 + 2)/6 = 5/6.
Reading your result
Use the main result together with its units and supporting figures. Display values are rounded; calculations keep their underlying precision. A change in inputs or assumptions can change the answer. Compare the step-by-step working with your intended use before relying on an estimate.
Frequently asked questions
Can a denominator be zero?
No. A fraction with denominator zero is undefined.
Are improper fractions allowed?
Yes. The result remains a simplified fraction and also includes a decimal equivalent.
Sources & methodology
This calculator uses the mathematical identity and assumptions stated above. No current rates, prices, or external data are loaded. Conversion tools use international unit definitions.
Formula review: October 24, 2026. Read our methodology.