Ratio Calculator
Simplify any ratio to its lowest terms or find the missing number in a proportion — handy for recipes, mixing and scaling.
Simplify ratio
Simplified
2 : 3 (÷8)
Solve A:B = C:D
D
15
Formula
A:B simplified = A÷GCD : B÷GCDHow to use the Ratio Calculator
- 1Enter the two parts of your ratio
- 2See the simplified form and the GCD
- 3Or enter A, B, C and solve for D in A:B = C:D
Frequently Asked Questions
How do I simplify a ratio?
Divide both sides by their greatest common divisor (GCD). For example, 16:24 simplifies to 2:3 because both divide by 8.
How do I solve a proportion?
Use cross-multiplication: if A:B = C:D, then D = B × C ÷ A. Example: 2:3 = 10:D → D = 3 × 10 ÷ 2 = 15.