Fraction Calculators
Add, subtract, multiply and divide fractions, simplify a fraction, and convert between fractions, decimals and percentages.
Fractions, decimals and percentages are three ways of writing the same quantity: 3/4, 0.75 and 75% are equal. These calculators do arithmetic with fractions and convert between the three forms.
Fraction arithmetic here is exact. Fractions are kept as whole-number numerators and denominators until the final step, so 1/3 + 1/3 + 1/3 gives exactly 1 rather than a rounded decimal.
Calculators in this category
Which calculator do I need?
- What is 2/3 + 3/4? The Fraction Calculator adds, subtracts, multiplies and divides fractions and mixed numbers and simplifies the result.
- What is 0.375 as a fraction? The Decimal to Fraction Calculator converts the decimal exactly as typed.
- What is 5/8 as a decimal? The Fraction to Decimal Calculator divides the numerator by the denominator.
- What is 12.5% as a fraction? The Percentage to Fraction Calculator gives the simplest exact fraction.
- What is 3/8 as a percentage? The Fraction to Percentage Calculator multiplies the fraction by 100.
Good to know
A typed decimal is converted exactly as entered: 0.333 becomes 333/1000, not 1/3. If you mean one third, enter it as a fraction.
A simplified fraction has a terminating decimal only when its denominator has no prime factors other than 2 and 5, so 1/8 = 0.125 but 1/3 and 1/7 recur. The fractions, decimals and percentages guide explains why.
Background reading
- Fractions, decimals and percentages Converting between the three forms, simplifying fractions, recognising terminating and recurring decimals, and avoiding rounding errors.