MihsabaHow to use
This ratio and proportion calculator covers the most useful tasks in one place: simplify A:B, show A/B as a decimal, find A's share of A+B, solve D in A:B = C:D when C is supplied, and optionally split a total using the same ratio.
- Enter A and B; both must be greater than zero.
- To solve a proportion, enter C and the calculator will solve D in A:B = C:D.
- To divide an amount or quantity, enter the optional total to see each side's share.
How it is calculated
Example
Example: 12:18 simplifies to 2:3. With C = 8, the proportion 12:18 = 8:D gives D = 12. Splitting a total of 500 in the ratio 2:3 gives shares of 200 and 300.
Important notes
A ratio is not automatically a percentage. A:B describes a relationship between two values, while A's share of the combined total is A ÷ (A+B). Decimal inputs are scaled to integers before simplification, with a practical precision limit to avoid floating-point artifacts.
Frequently asked questions
How do I simplify a ratio?
Scale decimal terms to integers when needed, then divide both terms by their greatest common divisor.
What is the difference between a ratio and a proportion?
A ratio compares two quantities, such as 2:3. A proportion states that two ratios are equal, such as 2:3 = 8:12.
How do I split a total in a 3:2 ratio?
Add the ratio parts first: 3+2=5. The first share is total × 3/5 and the second is total × 2/5.
Is this calculator free?
Yes. It is free to use and requires no account.