Which is bigger, 5/8 or 3/5? With unlike denominators it is hard to tell at a glance. Rewriting both fractions over the same denominator – or cross-multiplying – makes the comparison a simple comparison of whole numbers.
How to use the Comparing Fractions Calculator
- Fraction form
- Fraction 1: whole
- Fraction 1: numerator
- Fraction 1: denominator
- Fraction 2: whole
- Fraction 2: numerator
- Fraction 2: denominator
Everything is calculated in your browser, so results appear instantly and nothing you type is sent to a server.
How it works
Mixed numbers are first turned into improper fractions. Both fractions are rewritten over their least common denominator, and the numerators are compared.
Formula
Compare a/b and c/d: rewrite over LCD L and compare a·(L/b) with c·(L/d) (or compare a·d with c·b)
Worked example
Inputs — Fraction form: Simple fraction; Fraction 1: numerator: 5; Fraction 1: denominator: 8; Fraction 2: numerator: 3; Fraction 2: denominator: 5.
Results — Comparison = 5/8 > 3/5; Which is greater? = 5/8 is greater; Difference (first − second) = 1/40 ≈ 0.025; Steps = 1. Common denominator 40: 25/40 and 24/40
2. Compare the numerators: 25 > 24.
Key terms
- Equivalent fractions
- Fractions with the same value, such as 1/2 and 4/8.
Frequently asked questions
Which is bigger, 5/8 or 3/5?
5/8 = 25/40 and 3/5 = 24/40, so 5/8 is bigger.
What is the cross-multiplication shortcut?
a/b > c/d exactly when a·d > c·b (with positive denominators).
How do I compare fractions with the same numerator?
The one with the smaller denominator is larger.
Can I compare by converting to decimals?
Yes – 0.625 > 0.6 – but common denominators keep it exact.