Fraction to Percent Calculator
Convert a fraction to a percentage, or a percentage back to a fraction in lowest terms. Both directions on one page.
Fraction to percentage
As a decimal
0.75
As a percentage
75%
3 ÷ 4 × 100
Percentage back to a fraction
Reduced to lowest terms.
Percentage to fraction
As a decimal
0.625
Unreduced
62.5/100
In lowest terms
5/8
62.5 ÷ 100, reduced
The fraction to percentage formula
Percent = Numerator ÷ Denominator × 100
A percentage is simply a fraction with 100 on the bottom, so converting means rewriting your fraction with that denominator.
Worked example — 3/4
3 ÷ 4 = 0.75
0.75 × 100 = 75
So 3/4 is 75%.
How to turn a percentage into a fraction
- Write the percentage over 100.
- If it has decimals, multiply top and bottom until the top is a whole number.
- Divide both by their greatest common divisor.
Worked example — 62.5%
62.5 / 100
× 10 top and bottom → 625 / 1000
Both divide by 125 → 5 / 8
Why some fractions never end
A fraction gives a terminating decimal only when its reduced denominator has no prime factors besides 2 and 5 — the factors of ten.
- 1/8 = 12.5%. The denominator is 2 × 2 × 2, so it terminates.
- 1/3 = 33.333…%. Three is neither 2 nor 5, so it repeats forever.
- 1/7 = 14.2857142857…%, repeating in a six-digit cycle.
Any decimal you write for a repeating fraction is rounded. When exact arithmetic matters, keep the fraction.
Worth memorising
- 1/2 = 50%, 1/3 = 33.3%, 1/4 = 25%, 1/5 = 20%
- 1/6 = 16.7%, 1/8 = 12.5%, 1/10 = 10%, 1/16 = 6.25%
- 2/3 = 66.7%, 3/4 = 75%, 3/8 = 37.5%, 5/8 = 62.5%
Common questions
- How do I convert a fraction to a percentage?
- Divide the numerator by the denominator, then multiply by 100. For 3/4: 3 ÷ 4 = 0.75, and 0.75 × 100 = 75%.
- How do I convert a percentage back to a fraction?
- Put the percentage over 100 and reduce. 62.5% becomes 62.5/100, which scales to 625/1000 and reduces to 5/8.
- Why do some fractions give a repeating decimal?
- A fraction terminates only when its reduced denominator has no prime factors other than 2 and 5. One third is 33.333…% forever, because 3 is neither.
- Can a fraction be more than 100%?
- Yes. Any fraction where the numerator is larger than the denominator is over 100%. 5/4 is 125%.