Ratio of Two Numbers Calculator — Simplify A : B
Enter any two positive numbers to get the simplified A : B ratio in lowest terms, the decimal ratio A ÷ B, and the percentage each number represents of the combined total. A fraction bar shows the proportional split visually.
Simplified ratio: 3 : 4
- 1
GCD of A and B
GCD(3, 4) = 1 - 2
Simplified ratio A : B
3 : 4 - 3
Decimal ratio A ÷ B
3 ÷ 4 = 0.7500
How does this calculator work?
The simplified ratio A : B divides both numbers by GCD(A, B). For A = 6 and B = 9, GCD = 3 gives the simplified ratio 2 : 3. The decimal ratio is 6 ÷ 9 ≈ 0.667, and the percentage split is 40% (A) vs 60% (B) of the combined total.
Formula
How this is calculated
The ratio A : B compares two quantities directly. To express it in lowest terms, both values are divided by their greatest common divisor (GCD) — the largest integer that divides both without a remainder. For integers 6 and 9 the GCD is 3, so the simplified ratio is 2 : 3. For decimal inputs the ratio is displayed as entered because the GCD method applies cleanly only to whole numbers, but the proportional representation and percentage split are still computed correctly.
The decimal ratio A ÷ B tells you how many units of B fit into A. A ratio of 0.75, for example, means A is three-quarters the size of B. The "ratio to 1" form sets A = 1 and scales B accordingly, which is useful for comparing proportions across different absolute values.
Each number is also expressed as a percentage of the combined total A + B. For 3 : 4 the total is 7, so A accounts for 3/7 ≈ 42.9 % and B for 4/7 ≈ 57.1 %. This percentage split is the natural format for presenting ratios in contexts such as ingredient proportions, survey breakdowns, or resource allocation.
Frequently asked questions
Divide both numbers by their greatest common divisor (GCD). For 12 : 18 the GCD is 6, giving the simplified ratio 2 : 3. The GCD can be found by the Euclidean algorithm.
A ratio A : B compares two quantities. A proportion is the statement that two ratios are equal — for example 2 : 3 = 4 : 6. This calculator finds and simplifies the ratio A : B; to solve a proportion (a : b = c : d for an unknown) use a proportion or cross-multiplication calculator.
Yes — for example 1.5 : 2 is a valid ratio. The calculator shows decimal values directly since GCD simplification is only meaningful for integers. The percentage split and visual bar still reflect the correct proportions.
Also known as
TG we-Calculate Editorial Team. (2026). Ratio of Two Numbers Calculator — Simplify A : B [Online calculator]. TG we-Calculate. https://we-calculate.com/calculator/ratio-of-2-numbers-calculator
TG we-Calculate Editorial Team. "Ratio of Two Numbers Calculator — Simplify A : B." TG we-Calculate. 2026. https://we-calculate.com/calculator/ratio-of-2-numbers-calculator.
TG we-Calculate Editorial Team, "Ratio of Two Numbers Calculator — Simplify A : B," TG we-Calculate, 2026. [Online]. Available: https://we-calculate.com/calculator/ratio-of-2-numbers-calculator
@misc{wecalculate_ratio_of_2_numbers_calculator, title = {Ratio of Two Numbers Calculator — Simplify A : B}, author = {{TG we-Calculate Editorial Team}}, howpublished = {\url{https://we-calculate.com/calculator/ratio-of-2-numbers-calculator}}, year = {2026}, note = {TG we-Calculate} }
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