Ratio calculator — simplify ratios and solve proportions
Simplify any ratio to its lowest terms, see each part as a percentage share, and solve a proportion for a missing value.
Runs entirely in your browser — nothing is uploaded.
Two or more numbers, separated by spaces, commas or colons.
Solve a proportion — a : b = c : x
Decimal terms are scaled to whole numbers before simplifying, so 1.5 : 2.5 correctly becomes 3 : 5.
How to use
- Enter your terms. Two or more numbers, separated by spaces, commas or colons.
- Read the simplified ratio. Plus each term as a percentage of the whole, and a visual split.
- Or solve a proportion. Fill in a, b and c in the panel below to find x in a : b = c : x.
Questions
How do I simplify a ratio?
Divide every term by their greatest common divisor. 1920 : 1080 share a GCD of 120, giving 16 : 9. Decimal terms are scaled to whole numbers first, so 1.5 : 2.5 correctly becomes 3 : 5.
How do I solve a proportion?
Cross-multiply. For a : b = c : x, x = (b × c) ÷ a. Given 2 : 3 = 4 : x, x = (3 × 4) ÷ 2 = 6.
What is the difference between a ratio and a fraction?
A ratio compares parts to each other; a fraction compares a part to the whole. In a 2 : 3 mix there are 5 parts total, so the first is 2/5 — that is 40%, not 2/3.
Can I use this for aspect ratios?
Yes — enter the pixel dimensions. 1920 1080 simplifies to 16 : 9; 2560 1600 gives 16 : 10.