Ratio Calculator

When to use?

Use it to scale a recipe while keeping the ingredient ratio, to find the simplest form of a screen resolution, or to solve a proportion for the amount needed when diluting a concentrate.

How to use

• Simplify a ratio: enter two numbers and the simplest ratio (divided by the GCD) is shown.
• Solve a proportion: enter three values as A:B = C:? to compute the unknown.

Input Explanation

Enter the total and part values for the ratio, or the two numbers you want to compare.

Calculation Basis

Ratio simplification divides both numbers by their greatest common divisor (GCD) to reach the smallest integer ratio. A proportion is solved with ? = (B × C) / A.

Usage Examples

• Adjust ingredient ratios - Find the amount needed to scale up a 2:3 recipe ratio.
• Check a screen ratio - Instantly confirm that 1920:1080 simplifies to 16:9.
• Dilution concentration - Use a concentrate:diluent proportion to reach a target concentration.

Examples

• 1920:1080 → divided by GCD 120 = 16:9
• A:B = 2:3, C = 6 → ? = (3×6)/2 = 9

Cautions

• Entering 0 or a negative number for any term prevents a valid ratio calculation.
• When diluting or adjusting ratios, the order of mixing and the temperature can introduce physical errors in actual volume or density.

Guides

How to calculate a ratio

The ratio of two values A and B is A ÷ B, or (A ÷ B) × 100 as a percentage. To compare ratios meaningfully, use the same denominator (baseline).

Using ratios

Ratios are used for ingredient proportions, group composition, mixing, and more. Beyond a simple division, it matters to distinguish percent, ratio, and rate of change.

FAQ

How do I solve for ? in A:B = C:?

Use ? = (B × C) / A. It cannot be solved if A is 0.

Can decimal ratios be simplified?

Yes, a decimal ratio like 1.5:2 simplifies to an integer ratio (3:4).

How does ratio simplification work?

Both numbers are divided by their greatest common divisor (GCD) to reach the smallest integer ratio.

Are negative numbers supported?

Proportions support negative numbers.

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