Fraction calculator
Add, subtract, multiply or divide two fractions and get an exact answer reduced to its simplest form.
Result for the values shown.
Calculations run in your browser.
What to enter
| Input | Meaning and units |
|---|---|
| First numerator | Use a whole number in the stated format. Fractions and rounding are not interchangeable with exact integer inputs. |
| First denominator | Use a whole number in the stated format. Fractions and rounding are not interchangeable with exact integer inputs. |
| Operation | Choose the applicable option: Add (+), Subtract (−), Multiply (×), Divide (÷). |
| Second numerator | Use a whole number in the stated format. Fractions and rounding are not interchangeable with exact integer inputs. |
| Second denominator | Use a whole number in the stated format. Fractions and rounding are not interchangeable with exact integer inputs. |
Understanding your result
Read Result numerator, Result denominator in the units and model stated on this page. The formula a/b + c/d = (ad + bc)/(bd) defines the relationship; measurement accuracy and model applicability are separate from numerical precision.
Common mistakes
- Using a different mathematical definition or operation than the one stated by this tool.
Check your calculation
- Use the worked example as a known reference case, then change one input at a time and check the direction and units of the response.
Calculation checks, sources and review limits
How do I calculate with fractions and simplify the answer?
Enter both fractions as integer numerators and nonzero denominators. Choose an operation to obtain an exact reduced fraction.
Common uses
- Add fractions with different denominators.
- Multiply or divide fractions without decimal rounding.
How it works
Enter integer numerators and nonzero integer denominators. Addition and subtraction find a common denominator. Multiplication combines numerators and denominators; division multiplies by the reciprocal. The result is reduced by its greatest common divisor and its denominator is positive.
Worked example
1/2 + 1/3 = 3/6 + 2/6 = 5/6. A zero numerator simplifies to 0/1.