How to Convert Between Fractions and Percentages?
Fractions and percentages are two different ways to express a part of a whole. Knowing how to convert from one to the other is essential in mathematics, cooking, DIY and many everyday situations.
Conversion Methods
Pourcentage → Fraction
X% = X/100, puis simplifier avec le PGCD
Fraction → Pourcentage
(Numérateur ÷ Dénominateur) × 100 = X%
Conversion Examples
- 20% = 20/100 = 1/5 (divide by 20, the GCD)
- 75% = 75/100 = 3/4 (divide by 25)
- 1/2 = 0.5 × 100 = 50%
- 3/8 = 0.375 × 100 = 37.5%
Frequently Asked Questions
To simplify a fraction, divide the numerator and denominator by their Greatest Common Divisor (GCD). For example, 20/100: the GCD of 20 and 100 is 20, so 20/100 = 1/5.
Fractions are often more practical for mental calculations and certain applications (recipes, measurements). For example, it's easier to visualize '1/4 cup' than '25% of a cup'.
For decimal percentages: 0.5% = 0.5/100 = 5/1000 = 1/200. And 1.5% = 1.5/100 = 15/1000 = 3/200. The method is the same: convert to a fraction over 100, then multiply to eliminate decimals and simplify.
To convert a large fraction (e.g., 456/1200) to a percentage, divide the numerator by the denominator (456 ÷ 1200 = 0.38), then multiply by 100: 0.38 × 100 = 38%. Our tool does this calculation automatically.