Ratio Calculator
Simplify a ratio A:B to its lowest terms and see it as 1:n, as a decimal and as a percentage of the whole. Enter a total as well and the calculator splits it into two shares in that ratio.
- As 1 : n
- 1:1.5
- A ÷ B
- 0.666667
- A as a share of the whole
- 40%
- A’s share of the total
- 60
- B’s share of the total
- 90
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Formula
How to use it
- Enter the two sides of the ratio. Decimals are fine.
- Optionally enter a total amount to divide in that ratio.
- Read the simplified ratio and the two shares.
Worked examples
Simplify 12:18 and split 150 in that ratio
- Simplified ratio
- 2:3
- As 1 : n
- 1:1.5
- A as a share of the whole
- 40%
- A’s share of the total
- 60
- B’s share of the total
- 90
A 1920 × 1080 screen
- Simplified ratio
- 16:9
- A ÷ B
- 1.777778
A ratio is not a fraction of the whole
In a 2:3 ratio there are 5 parts in total, so A is 2/5 (40%) of the whole and B is 3/5 (60%) — not 2/3. To split 150 in the ratio 2:3, each part is 150 ÷ 5 = 30, giving 60 and 90.
Ratios with decimals
To simplify 1.5:2.5, first multiply both sides by 10 to clear the decimals (15:25), then divide by the greatest common factor, 5, to get 3:5. The calculator does this automatically for up to six decimal places.
A 1920 × 1080 screen simplifies to 16:9, and 1024 × 768 to 4:3.
Questions people ask
How do I simplify the ratio 12:18?
Divide both sides by their greatest common factor, 6, to get 2:3.
How do I split $150 in the ratio 2:3?
Add the parts (2 + 3 = 5), divide the total by 5 to get $30 per part, then multiply: $60 and $90.
What is 1920:1080 as a ratio?
16:9. Both numbers divide by 120.