How to Convert a Fraction to a Decimal and a Percentage (With Examples)
Short answer
To convert a fraction to a decimal, divide the numerator (top number) by the denominator (bottom number). For 3/8, 3 ÷ 8 = 0.375. To get a percentage, multiply the decimal by 100: 0.375 × 100 = 37.5%. Some fractions, such as 1/3, never end and give a repeating decimal (0.333…), which you round to the number of places you need.
Fractions, decimals and percentages are three ways of writing the same idea: a part of a whole. A test score of 18 out of 25, a "one-third off" sale sign and a recipe that asks for 3/4 cup all hide a decimal and a percentage inside them. Being able to switch between the three quickly helps with homework, exam maths sections and everyday shopping. This guide shows the one rule you need, a few shortcuts, and how to deal with decimals that go on forever. Our free fraction calculator checks every answer.
The one rule: top divided by bottom
A fraction bar simply means "divided by". So 3/4 is the same as 3 ÷ 4, and doing that division gives the decimal.
- Write the division. The numerator goes inside, the denominator outside: 3 ÷ 4.
- Divide. 4 does not go into 3, so write 0 and a decimal point, add a zero to make 30, and continue: 30 ÷ 4 = 7 remainder 2, then 20 ÷ 4 = 5. The answer is 0.75.
- Stop or round. If the remainder becomes 0, you are done. If it never does, the decimal repeats, and you round it (see below).
On a phone or the scientific calculator, just type 3 ÷ 4 and press equals.
Example 1: a fraction that ends (terminating decimal)
Convert 7/8 to a decimal.
- 7 ÷ 8: write 0., then 70 ÷ 8 = 8 remainder 6.
- 60 ÷ 8 = 7 remainder 4, then 40 ÷ 8 = 5 remainder 0.
- So 7/8 = 0.875.
A quick way to tell in advance whether a fraction will end: simplify it first, then look at the denominator. If its only prime factors are 2 and 5 (like 2, 4, 5, 8, 10, 16, 20, 25), the decimal ends. Any other factor, such as 3, 7 or 11, gives a repeating decimal.
Example 2: a fraction that repeats
Convert 2/3 to a decimal. 20 ÷ 3 = 6 remainder 2, and that same remainder 2 comes back every time, so you get 0.6666… forever. Mathematicians write this with a bar over the repeating digit, or as 0.(6). For everyday use, round it: to two decimal places 2/3 ≈ 0.67.
Some fractions repeat in longer blocks. 1/7 = 0.142857142857…, where the six digits 142857 repeat. Rounded to three places that is 0.143.
Example 3: mixed numbers
For a mixed number like 2 3/5, keep the whole number and convert only the fraction: 3 ÷ 5 = 0.6, so 2 3/5 = 2.6. You can also turn it into an improper fraction first (13/5) and divide: 13 ÷ 5 = 2.6. Both ways give the same answer, so use whichever feels easier. Our guide to adding and multiplying fractions explains improper fractions in more detail.
Shortcut: make the denominator 10, 100 or 1,000
If you can multiply the bottom number to reach 10, 100 or 1,000, you can skip long division. Multiply the top by the same number.
- 3/5 = 6/10 = 0.6
- 7/20 = 35/100 = 0.35
- 9/25 = 36/100 = 0.36
- 3/8 = 375/1,000 = 0.375
This trick is very handy in timed exams because it is faster than dividing and less error-prone.
From decimal to percentage
Once you have the decimal, a percentage is one step away: multiply by 100, which moves the decimal point two places to the right. So 0.875 becomes 87.5%, and 0.35 becomes 35%. That is exactly how a test score works. If you got 18 out of 25, then 18 ÷ 25 = 0.72, which is 72%. Our guide on calculating a grade percentage covers weighted marks, and the percentage calculator handles the reverse question, such as "what is 72% of 25?".
Common fractions as decimals and percentages
| Fraction | Decimal | Percentage |
|---|---|---|
| 1/2 | 0.5 | 50% |
| 1/3 | 0.333… | 33.3% |
| 2/3 | 0.666… | 66.7% |
| 1/4 | 0.25 | 25% |
| 3/4 | 0.75 | 75% |
| 1/5 | 0.2 | 20% |
| 1/6 | 0.1666… | 16.7% |
| 1/8 | 0.125 | 12.5% |
| 3/8 | 0.375 | 37.5% |
| 1/10 | 0.1 | 10% |
| 1/20 | 0.05 | 5% |
Learning the halves, quarters, fifths and eighths by heart saves a lot of time. Everything else can be worked out from them: 5/8 is 1/2 + 1/8, which is 0.5 + 0.125 = 0.625.
Why this matters in exams and daily life
Competitive exams such as bank, railway and staff-selection tests often ask you to compare fractions like 5/7 and 7/10 in seconds. Turning both into decimals (about 0.714 and 0.7) makes the answer obvious. If you are preparing for one, our SSC CGL guide, the exams hub and our free study pages help you plan revision. ViralScopeHub is not affiliated with any exam board; always check the official notice for the current pattern.
In daily life the same skill helps you read a "1/4 off" sale (25% off), split a bill, or scale a recipe. For recipes and shared costs, our guide on simplifying a ratio and the ratio calculator pick up where fractions leave off, and the average calculator is useful once you have a list of decimal scores.
Common mistakes to avoid
- Dividing the wrong way round. 3/4 is 3 ÷ 4 (0.75), not 4 ÷ 3 (1.33).
- Forgetting the zero placeholder. 1/20 is 0.05, not 0.5. Check that the answer makes sense: 1/20 is a small slice, so the decimal should be small.
- Rounding too early. Keep a few extra decimal places while you work and round only the final answer.
- Mixing up 0.5% and 50%. Multiply the decimal by 100 to get the percentage, and do it only once.
VSH take: most people only need two things: "top divided by bottom" and the table of common fractions above. With those, nearly every fraction question turns into a quick calculator check.
Frequently asked questions
How do you convert a fraction to a decimal?
Divide the numerator by the denominator. For example, 3/8 = 3 ÷ 8 = 0.375.
How do you turn a fraction into a percentage?
Convert it to a decimal first, then multiply by 100. For 3/4, 3 ÷ 4 = 0.75, and 0.75 × 100 = 75%.
Why do some fractions give repeating decimals?
After simplifying, if the denominator has any prime factor other than 2 or 5, the division never ends and the digits repeat, as in 1/3 = 0.333…
What is 1/3 as a decimal rounded to two places?
1/3 is 0.333… which rounds to 0.33. As a percentage it is about 33.3%.
How do you convert a mixed number to a decimal?
Keep the whole number and convert the fraction part. For 2 3/5, 3 ÷ 5 = 0.6, so the answer is 2.6.
