A fraction converts to a percentage by dividing its numerator
by its denominator and multiplying by 100, the fraction
7/8 is 87.5%, meaning it represents 87.5 parts out of a
hundred.
This is the same division-then-multiply shape that underlies
every percentage calculation on this site, applied to a
fraction's two terms instead of an original and a new value.
Fractions and percentages describe the same underlying
proportion in two different notations, and converting between
them is often the missing first step before a percentage
decrease calculation can even begin, a recipe scaled "down
by a third," a discount described as "a quarter off," or a
measurement given as a fraction on an old data sheet all need
this conversion before the rest of the math makes sense.
Fraction to Percent Formula
Percentage=NumeratorDenominator×100
Numerator
The top number of the fraction, shown in blue, matching the first field above.
Denominator
The bottom number of the fraction, shown in teal, matching the second field above.
Unlike most formulas on this site, there's no absolute value to worry about here, a fraction's sign simply carries through the division normally, since there's no "original value" whose sign needs protecting.
How to Convert a Fraction to a Percent
Divide the numerator by the denominator
Multiply the decimal by 100
Attach the percent sign
For a mixed number, convert it to an improper fraction first, multiply the whole number by the denominator, add the numerator, and keep the same denominator, before applying these three steps.
Fraction to Percent Examples
Example 1, 7/8 as a percentage
87.50%
Divide7 ÷ 8 = 0.875
Multiply by 1000.875 × 100 = 87.50%
7/8 is 87.5%, a fraction just past three-quarters.
Example 2, 5/6 as a percentage
83.33%
Divide5 ÷ 6 = 0.833333…
Multiply by 1000.833333… × 100 = 83.33%
5/6 is 83.33%, repeating, sixths, like thirds, never terminate cleanly in decimal form.
Relationship to Percentage Decrease
Fractions and percentage decrease meet whenever a change is
described in fraction language: "decreased by one quarter"
means a 25% decrease, "cut by a third" means roughly a 33.33%
decrease, and "reduced by half" means a 50% decrease. Converting
the fraction to a percentage first is exactly what lets you plug
it into the percentage decrease formula as a
rate, see the reverse percentage
calculator to go from a known fraction-based decrease back
to an original value.
Common Fraction-to-Percent Reference
These ten fractions cover most of what comes up in everyday percentage decrease conversations, memorizing even a few of them makes mental estimation noticeably faster.
Fraction
Percentage
1/2
50%
1/3
33.33%
2/3
66.67%
1/4
25%
3/4
75%
1/5
20%
2/5
40%
1/8
12.5%
3/8
37.5%
1/10
10%
Notice the pattern within each family, eighths are all multiples of 12.5%, fifths are all multiples of 20%, and thirds never terminate cleanly. Recognizing which family a fraction belongs to is often faster than dividing it out by hand.
Frequently Asked Questions
Questions specific to fraction conversion, including a few edge cases that trip people up when the numerator or denominator isn't a tidy whole number.
How do I convert a mixed number to a percent?
Convert the mixed number to an improper fraction first, 1¾ becomes 7/4, then divide the numerator by the denominator and multiply by 100 as usual. 7/4 converts to 175%.
What is 1/3 as a percent, and why does it repeat?
1/3 is 33.333…%, repeating forever, because 1 doesn't divide evenly by 3 in base ten. Most contexts round it to 33.33% or 33.3%; a few round up to 33.34% to make three copies sum to exactly 100.00%.
How do I convert a percent back into a fraction?
Write the percentage over 100 and simplify, 40% becomes 40/100, which simplifies to 2/5. The decimal to percent converter covers the equivalent conversion for decimals.
Can the denominator be zero?
No, a fraction with a denominator of zero is undefined, not infinite or 100%, because division by zero has no defined value at all.
How do I convert a fraction to a percentage decrease?
Subtract the fraction's percentage from 100% if it represents what remains, or use the fraction directly as the decrease rate if it represents the portion removed. "Reduced to three-quarters" is a 25% decrease; "reduced by three-quarters" is a 75% decrease. The wording changes which one applies.
What if my fraction is greater than 1, like 5/4?
It converts to a percentage greater than 100%: 5/4 is 125%, meaning the numerator is more than the whole denominator represents. This is normal and simply means the value exceeds a single whole unit.
How is converting a fraction to a percent different from a ratio?
A fraction and a ratio can describe the same relationship, but a ratio (like 3:4) isn't divided the same way a fraction is. Converting a ratio to a percentage first requires expressing it as a fraction of the total (3 parts out of 7 total, not out of 4).
Can I enter a negative numerator or denominator?
Yes, the calculator handles negative values the same way ordinary division does. A negative numerator with a positive denominator (or vice versa) produces a negative percentage; two negatives produce a positive one.
Should I simplify a fraction before converting it?
It doesn't change the result, 2/4 and 1/2 both convert to exactly 50%, since simplifying a fraction doesn't change its value, only how it's written.
Is there a shortcut for common fractions like eighths?
Memorizing that 1/8 is 12.5% makes every other eighth quick to derive by multiplication, 3/8 is 3 × 12.5% = 37.5%, 5/8 is 5 × 12.5% = 62.5%, and so on.