Ratio Calculator
Simplify a ratio, solve a proportion such as 16:9 = 1920:?, or share an amount in a ratio.
Result
Enter a ratio.
How ratios work
A ratio compares quantities: 2:3 means for every 2 of the first there are 3 of the second. Two ratios are in proportion when A ÷ B = C ÷ D, so any missing value can be found by cross-multiplying: D = B × C ÷ A.
Example: a 16:9 screen 1,920 pixels wide is 1,920 × 9 ÷ 16 = 1,080 pixels high.
Frequently asked questions
How do I simplify a ratio?
Divide every part by their highest common factor. 1920:1080 divides by 120 to give 16:9.
How do I share money in a ratio?
Add the parts to get the total number of shares, divide the amount by that, then multiply by each part. £100 in the ratio 2:3 is 5 shares of £20, so £40 and £60.
How do I scale a picture without stretching it?
Keep the width-to-height ratio the same. Choose “Solve”, enter the original width and height as A and B, the new width as C, and leave D blank to get the new height.
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