Ratio Calculator
Simplify a ratio, solve for a missing value, and see the split as percentages.
Results
| Item | Value |
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Steps
| Step | Working |
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Quick Answer
To simplify a ratio, divide both numbers by their greatest common factor. For 15:40, the factor is 5, so the ratio is 3:8. To scale it, multiply by the new value and divide by the old one: 6 : B means B = 6 × 40 ÷ 15 = 16.
Embed this calculator
Adjust the size if needed, then copy the code below into your page or blog. The calculator will load in an iframe and stay updated automatically.
Table of Contents
How This Ratio Calculator Works
A ratio compares two amounts. This calculator simplifies your ratio, shows it as a fraction and as percentages, and scales it to a new size if you enter a new value for A.
Quick explanation: divide both numbers by their greatest common factor.
- A and B: the two amounts you are comparing.
- Shares: how much of the total each amount is.
- New value: optional, to find the matching B.
Core Formulas
- Simplify: A ÷ GCF : B ÷ GCF
- Missing value: new B = new A × B ÷ A
- Share of A: A ÷ (A + B) × 100
Worked Example
A recipe uses 300 g of flour and 200 g of sugar. You want to use 450 g of flour.
- Simplified ratio = 3 : 2
- New sugar = 450 × 200 ÷ 300 = 300 g
- Shares = 60% flour and 40% sugar
Where Ratios Are Used
- Cooking: scaling a recipe up or down.
- Screens and images: keeping the same shape, such as 16:9.
- Maps and models: working with scale.
- Sharing: dividing an amount in a set proportion.
Frequently Asked Questions
Find the greatest common factor of both numbers and divide each by it. For example, 15:40 becomes 3:8.
Cross-multiply. If A:B = C:X, then X = C × B ÷ A.
Divide one part by the total of both parts, then multiply by 100.
Yes. The calculator scales decimals to whole numbers before simplifying.
It means 16 units of width for every 9 units of height, a common screen shape.
References & Sources
| Source | Used For | Link |
|---|---|---|
| Wikipedia, Ratio | Definition and use of ratios. | https://en.wikipedia.org/wiki/Ratio |
| Wikipedia, Greatest common divisor | How to find the common factor. | https://en.wikipedia.org/wiki/Greatest_common_divisor |