Ratio Calculator

Simplify ratios, solve proportions (a:b = c:?), scale ratios, and compare multiple ratios.

Mode

Reduce a ratio A : B to its simplest form.

Simplified Ratio
3 : 5
GCD = 5
Original ratio15 : 25
Simplified3 : 5
As decimal1 : 1.666667
A as fraction of total15/40 (37.50%)
B as fraction of total25/40 (62.50%)

Results

PropertyFormula
Simplify A:Bdivide by GCD(A, B)
ProportionA:B = C:D → D = BC/A
Part of totalA/(A+B) × 100%
As decimalA ÷ B
EquivalentA:B = kA:kB (any k)

Common Ratios

RatioSimplifiedDecimalUse
16:916:91.778Widescreen
4:34:31.333Standard screen
1:11:11.000Square
3:23:21.500Camera sensor
2:12:12.000Panoramic
1:1.6181:φ0.618Golden ratio
1:21:20.500Half