Ratio Calculator
Simplify a ratio, scale it to a new total, or solve for the missing term in a proportion.
Your details
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Simplified ratio
16 : 9
Already in lowest terms
Includes your inputs, the full breakdown, and every row of the table.
Simplified
16 : 9
As a decimal
1.7778
First as a percentage of total
64.00%
Scaled to 1
1.778 : 1
- Original ratio
- 16 : 9
- Greatest common divisor
- 1
- Simplified
- 16 : 9
What this means
- A ratio compares parts to each other; a fraction compares a part to the whole. In a 3:1 ratio the first item is three quarters of the total, not three times the total.
How the ratio calculation works
A ratio describes relative size without committing to absolute quantities, which is what makes it so useful for recipes, mixtures, screen dimensions and dividing money. Simplifying works exactly as it does for fractions — divide every term by their greatest common divisor — so 1920:1080 reduces to 16:9, the aspect ratio you actually recognise.
The distinction worth holding onto is between a ratio and a fraction. A ratio of 3:1 means four parts in total, with the first quantity taking three of them, or seventy-five percent. Reading that ratio as three quarters versus one quarter is correct; reading it as three times the whole is not, and that slip is behind a lot of botched mixing and unfair splits.
Frequently asked questions
How do I split a bill or a profit in a given ratio?
Add the terms together to find the total number of parts, divide the amount by that total to find what one part is worth, then multiply by each term. Splitting $1,000 in a 3:2 ratio gives five parts of $200, so the shares are $600 and $400.
What is the difference between a ratio and a proportion?
A ratio compares two quantities; a proportion states that two ratios are equal. Proportions are what let you scale — knowing that 2:3 equals 8:x tells you immediately that x is 12, by cross multiplying.
How do aspect ratios work?
They are simply width to height, simplified. A 1920 by 1080 screen reduces to 16:9 because both numbers divide by 120. Two screens with the same aspect ratio have the same shape regardless of size, which is why the ratio rather than the resolution determines whether an image fits without bars.
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Disclaimer. This calculator is provided for general information and educational purposes only and does not constitute financial, tax, legal, medical, or engineering advice. Results are estimates based on the inputs you provide and the assumptions described above. Confirm any figure with a qualified professional before acting on it.