Type a percent and get the fraction in simplest form, with every step shown: over 100, clear the decimal, find the GCD and divide. Repeating percents like 33.333% become 1/3.
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This percent to fraction converter is for students showing their working, teachers making answer keys and anyone who wants to see a percent as “1 in 8” instead of 12.5%. You get the simplest fraction, the full set of steps with the greatest common divisor, the decimal and the mixed number for values over 100%.
How Do You Convert a Percent to a Fraction?
To convert a percent to a fraction, write it over 100, clear any decimal, then divide top and bottom by their greatest common divisor. For example, 12.5% = 12.5/100 = 125/1000. The GCD of 125 and 1000 is 125, so the simplest fraction is 1/8. Likewise 45% = 45/100 = 9/20.
What Are the Steps to Turn a Percent Into a Fraction?
The steps are: put the percent over 100, multiply top and bottom by 10 for each decimal place, then simplify by the greatest common divisor. A percent means parts per hundred, so 45% is already the fraction 45/100 before it is simplified.
simplest = (top ÷ GCD) / (bottom ÷ GCD)
The greatest common divisor (GCD) is the largest whole number that divides both numbers. The tool finds it with the Euclidean algorithm: divide the larger number by the smaller, keep the remainder, and repeat until the remainder is 0. For 825 and 10,000 that runs 10,000 = 12 × 825 + 100, then 825 = 8 × 100 + 25, then 100 = 4 × 25 + 0, so the GCD is 25 and 8.25% = 33/400. A fraction whose top and bottom share no factor except 1 is in simplest form, also called lowest terms. The GCF calculator shows the same divisor for any two numbers.
Percent to Fraction Conversion Table
| Percent | Over 100 | Simplest fraction |
|---|---|---|
| 2.5% | 25/1000 | 1/40 |
| 8.333…% | 75/900 | 1/12 |
| 12.5% | 125/1000 | 1/8 |
| 16.666…% | 150/900 | 1/6 |
| 20% | 20/100 | 1/5 |
| 33.333…% | 300/900 | 1/3 |
| 37.5% | 375/1000 | 3/8 |
| 45% | 45/100 | 9/20 |
| 62.5% | 625/1000 | 5/8 |
| 66.666…% | 600/900 | 2/3 |
| 87.5% | 875/1000 | 7/8 |
| 150% | 150/100 | 3/2 = 1 1/2 |
How Do You Convert a Repeating Percent Like 33.333% to a Fraction?
You convert a repeating percent by treating the digits as a repeating decimal that goes on forever, then using algebra so the endless tail cancels out. Let x = 33.333…%. Then 10x = 333.333…%, and 10x − x = 300%, so 9x = 300% and x = 300/9 %. Dividing by 100 gives 300/900, and the GCD of 300 and 900 is 300, which leaves exactly 1/3. The tool spots a repeating digit when it appears at least 3 times after the decimal point, or a block of 2 to 6 digits that appears twice, such as 14.285714285714% = 1/7. Press “Exact as typed” if you meant the value literally: 33.333% is then 33,333/100,000. To go the other way, the fraction to decimal converter marks the repeating block with a bar.
What Is a Percent Over 100 as a Fraction?
A percent over 100 becomes an improper fraction, where the top is larger than the bottom, and it can also be written as a mixed number. For example, 150% = 150/100 = 3/2, which is 1 1/2. For adding or multiplying the fractions you get, use the fraction calculator.
Worked Example
A recipe blog says a dough is 12.5% sugar by weight and you want it as a fraction. Enter 12.5 and the tool shows 1/8, with the line 12.5% = 125/1,000 = 1/8. The steps show 1,000 = 8 × 125 + 0, so the GCD is 125, and the decimal is 0.125. Now type 33.333: with “Spot repeating digits” on, the tool reads it as 33.(3)% and gives 1/3, through 300/900 and a GCD of 300. Typing 150 gives 3/2, shown as the mixed number 1 1/2.
How Do You Use the Percent to Fraction Converter?
Type the percent
Enter a percent such as 12.5, 45 or 33.333. The % sign is optional and negatives work.
Choose how to read repeats
Keep Spot repeating digits for values like 33.333%, or pick Exact as typed for the literal value.
Read the simplest fraction
The big result is the fraction in lowest terms, with the full chain above 100 shown below it.
Check decimal, mixed number and GCD
The boxes show the decimal, the mixed number, the GCD used, and the steps list every division.
Frequently Asked Questions
What is 12.5% as a fraction?
12.5% as a fraction is 1/8. Write 12.5/100, multiply top and bottom by 10 to get 125/1000, then divide both by their GCD of 125. So 12.5% is one eighth, or 1 in 8.
What is 66.67% as a fraction?
Exactly as typed, 66.67% is 6,667/10,000, which does not simplify. It is usually a rounded form of 66.666…%, which is exactly 2/3. Type 66.666 with Spot repeating digits on to get 2/3.
What is 0.5% as a fraction?
0.5% as a fraction is 1/200. Write 0.5/100, multiply by 10 to get 5/1000, then divide top and bottom by the GCD of 5. Half of one percent is 1 part in 200.
What is 8.25% as a fraction?
8.25% is 33/400. Over 100 it is 8.25/100, which becomes 825/10,000 after multiplying by 100. The Euclidean algorithm finds a GCD of 25, and 825 ÷ 25 = 33, 10,000 ÷ 25 = 400.
Why does 33.333% give 1/3 and not 33333/100000?
The digit 3 repeats, so the tool assumes you mean 33.333…% going on forever, which is exactly 1/3. If you really mean the cut off value, press Exact as typed and you get 33,333/100,000.
How do I turn a fraction back into a percent?
Divide the top by the bottom and multiply by 100. For 3/8, 3 ÷ 8 = 0.375, and 0.375 × 100 = 37.5%. For 1/3 you get 33.333…%, which repeats forever.
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Last reviewed: October 2026