Ratio calculator
Choose whether to find the missing term or to simplify a ratio, then enter the numbers you know.
- Proportions
- Free, no sign-up
Free to use, no account. More everyday tools
How to use it
- Choose solve or simplify.
- Enter A and B.
- If you are solving, enter C as well.
The two questions
Solve computes D = B × C / A, so 2 : 4 = 3 : 6. A cannot be zero. Simplify reduces two whole numbers by their greatest common divisor, so 8 : 12 becomes 2 : 3. Decimals are shown rounded rather than forced into a fraction.
The page does not convert units. If A is in hours and C is in minutes, convert them to the same unit first.
Private by design
Privacy
The numbers stay in this tab and are not uploaded.
Questions
What if A is zero?
The proportion cannot be solved. The page will say so.
Can B be zero?
Yes. D is then zero when you are solving.
Is 1 : 2 the same as 0.5?
As a ratio, 1 : 2 means the second term is twice the first. It is not the single number 0.5 unless you divide them.