Fraction/Decimal/Percent Converter
Convert between fractions, decimals, and percentages instantly.
Enter any fraction, decimal, or percentage and see all three forms with simplification.
Fractions, decimals, and percentages are three different ways to express the same value. Being able to convert fluently between them is a fundamental numeracy skill used in finance, cooking, science, and everyday life.
The conversion triangle:
Fraction → Decimal: divide numerator by denominator 3/8 = 3 ÷ 8 = 0.375
Decimal → Percentage: multiply by 100 0.375 × 100 = 37.5%
Percentage → Decimal: divide by 100 37.5 ÷ 100 = 0.375
Decimal → Fraction: write over 1, multiply to clear decimal, then simplify 0.375 = 375/1000 = 3/8
Percentage → Fraction: write over 100, then simplify 37.5% = 37.5/100 = 375/1000 = 3/8
Common equivalents to memorise:
| Fraction | Decimal | Percentage |
|---|---|---|
| 1/2 | 0.5 | 50% |
| 1/4 | 0.25 | 25% |
| 3/4 | 0.75 | 75% |
| 1/3 | 0.333… | 33.3% |
| 2/3 | 0.666… | 66.7% |
| 1/5 | 0.2 | 20% |
| 1/8 | 0.125 | 12.5% |
| 1/10 | 0.1 | 10% |
Worked example: A sale item is reduced by 3/8. What percentage discount is that? 3/8 = 0.375 = 37.5% discount.
Practical uses:
- Nutrition labels: 12g fat in a 40g serving = 12/40 = 0.3 = 30% fat by weight
- Test scores: 17/20 = 0.85 = 85%
- Recipe scaling: 2/3 of a recipe = 66.7% of each ingredient
- Odds and shares: a 5/8 stake in something is a 62.5% share
A trap worth naming. “A quarter of a percent” and “a quarter as a percent” are different numbers. A quarter as a percent is 25%. A quarter of a percent is 0.25%, which as a decimal is 0.0025. Interest rates and credit-card fees are quoted the second way, so a rate that rises “by a quarter” almost always means 0.25 percentage points, not a 25% increase. This calculator does the first reading: enter 1 and 4 and you get 25%.
Decimals that never end. Divide by anything whose prime factors are not just 2s and 5s and the decimal repeats forever. 1/3 gives 0.333…, 1/7 gives 0.142857 repeating in a six-digit cycle, 1/6 gives 0.1666… A denominator of 8 (which is 2×2×2) terminates neatly at 0.125, and so does anything over 10, 20, 40 or 200. That is the whole rule, and it explains why 1/3 has to be rounded on screen while 3/8 does not.
Going the other way, from a decimal back to a fraction, the calculator reads exactly the digits you typed. Enter 0.333 and you get 333/1000, not 1/3, because 0.333 genuinely is not one third. If you want thirds, enter the fraction.
Improper fractions and mixed numbers. Anything over 100% is an improper fraction: 7/4 is 175%, and as a mixed number that is 1 3/4. Recipes and tape measures use mixed numbers, spreadsheets and percentages do not, and the calculator prints both so you can move between the two without doing it in your head.
How we build and check this calculator
This calculator runs entirely in your browser, so the numbers you enter stay on your device. The math behind it is written by hand and tested against worked examples and standard references before the page goes live.
SuperGlobalCalculator is independently built and maintained. See how we build and verify our calculators.