Ratio Calculator

What is the Ratio Calculator?

Simplify a ratio and scale it to a new total or term. Ratios compare quantities, and simplifying or scaling them keeps mixtures, recipes, image sizes and proportions consistent.

How to use the Ratio Calculator

1. Enter your first term, your second term, your scale so a equals.
2. Results update automatically as you type; you can also press Calculate.
3. Read the output: simplified ratio, scaled ratio, as a fraction a/b.
4. Use the 📊 chart to see the result visually, then copy or share it.

Formula and method

Worked example

With first term = 16, second term = 24, scale so a equals = 10, the Ratio Calculator returns simplified ratio: 2:3; scaled ratio: 10 : 15; as a fraction a/b: 0.666666666667.

Where the Ratio Calculator helps in real life

A concrete mix calls for cement, sand and gravel in a 1:2:3 ratio and you need 120 kg in total. Scaling the ratio gives 20 kg, 40 kg and 60 kg.

A photographer wants to resize a 4000 × 6000 pixel photo while keeping its shape. Simplifying gives 2:3, so any 2:3 size will not distort it.

Common mistakes to avoid

• Mixing units between parts of the ratio.
• Scaling one part without scaling the others.
• Confusing a 1:2 ratio with one half of the total.
• Rounding parts so they no longer add up to the total.

💡 Practical tip: A 1:2 ratio means one third and two thirds of the total, not one half and one whole.

Tips for better results

• Simplify ratios by dividing by the greatest common divisor.
• Check that scaled parts add up to the total.
• Use the proportion calculator for single missing values.

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