Ratio Calculator
Simplify, solve, scale and split ratios.
Use via API
Simplify a ratio (4:6 → 2:3, with percentages), solve a proportion A:B = C:D for the missing value, or split an amount in a ratio. Send JSON, get JSON back.
POST https://pithlab.com/api/v1/tools/ratio-calculator
curl https://pithlab.com/api/v1/tools/ratio-calculator \
-H "Authorization: Bearer $PITHLAB_KEY" \
-H "Content-Type: application/json" \
-d '{"mode":"split","ratio":"2:3:5","total":1000}'About the Ratio Calculator
Simplify ratios (decimals too), solve A:B = C:? for a missing value, split an amount in a given ratio, and convert a ratio to percentages.
How to use the Ratio Calculator
- Choose what you want to do: simplify a ratio, solve a proportion, or split an amount in a ratio.
- Type the ratio with colons (2:3:5). For a proportion, fill in three of A, B, C and D and leave the unknown blank.
- Read the answer as you type, with the ratio as percentages, and copy it.
Examples
Input
1.5 : 2.25
Output
1.5 : 2.25 = 2 : 3 (40% : 60%)
Input
1920 : 1080
Output
1920 : 1080 = 16 : 9 (64% : 36%)
Input
4 : 6 = 10 : ?
Output
4 : 6 = 10 : 15
Input
2 : 3 : 5 of 1000
Output
1,000 split 2 : 3 : 5 is 200, 300 and 500
Frequently asked questions
How do I simplify a ratio?
Divide every term by their greatest common divisor. 12 : 18 has a GCD of 6, so it simplifies to 2 : 3. With decimals, first multiply every term by the same power of 10 to make them whole: 1.5 : 2.25 becomes 150 : 225, which simplifies to 2 : 3.
How do I solve a proportion?
Cross-multiply. If A : B = C : D then A × D = B × C, so the missing D is B × C ÷ A. For 4 : 6 = 10 : ?, the answer is 6 × 10 ÷ 4 = 15.
How do I split an amount in a ratio?
Add the terms to get the number of parts, divide the amount by that, then multiply by each term. Splitting 1,000 in 2 : 3 : 5 gives 10 parts of 100, so the shares are 200, 300 and 500.
What does the 1 : n form mean?
It divides every term by the first one, so you can compare ratios at a glance. 4 : 6 is 1 : 1.5, meaning 1.5 of the second for every 1 of the first.