Ratio Calculator
Formula
Ratio = A ÷ B
A ratio compares two quantities. 12:8 simplifies to 3:2 (divide both by 4). The decimal form is 1.5.
How to use
- Enter the first quantity in the A field.
- Enter the second quantity in the B field.
- Read the decimal ratio plus A-per-1-B and B-per-1-A values.
Example
For A = 12 and B = 8: 12 ÷ 8 = 1.5. This means A is 1.5 times B, or the ratio 3:2.
Frequently Asked Questions
How do I simplify a ratio?
Divide both numbers by their greatest common divisor. 12:8 → divide by 4 → 3:2.
What does a ratio like 16:9 mean as a decimal?
Dividing 16 by 9 gives about 1.778, meaning the first quantity is roughly 1.78 times the second. This is the aspect ratio of most TVs and monitors, where the screen is 1.78 times as wide as it is tall. Converting a ratio to a decimal makes it easy to compare two ratios that aren't written in the same terms.
How do I split an amount according to a ratio?
Add the parts of the ratio together to get the total number of shares, then divide the amount by that total and multiply by each part. For example, splitting $100 in a 3:2 ratio means 5 total shares, so each share is $20 — giving $60 and $40. This is the common method for dividing profits, ingredients, or costs proportionally.