Ratio Calculator

How to use the Ratio Calculator

Reduce a two-number ratio to lowest whole-number terms, then create an equivalent ratio with one shared nonzero multiplier.

Simplify two-part ratios, compare equivalent forms, and scale both sides together. The tool is useful for recipes, maps, mixtures, dimensions, and proportional planning.

Fieldlet calculates locally and shows a practical estimate. Confirm consequential financial, contractual, health, or compliance decisions with an authoritative source.

1. Enter the first and second whole-number terms.
2. Fieldlet divides both by their greatest common divisor.
3. Enter a nonzero multiplier to scale both reduced terms without changing the proportion.

Last reviewed for accuracy: 2026-09-01

Worked examples

How the result is produced

Integer ratios are simplified by dividing both sides by their greatest common divisor. Scaling multiplies or divides both terms by the same nonzero factor so the proportion remains equal.

• a:b is equivalent to a ÷ b when b is nonzero
• Simplification changes the terms but not the proportion
• Units must be compatible before forming a meaningful ratio

Build an equivalent ratio

After simplification, the multiplier applies to both reduced terms. A multiplier of 2 turns 3:4 into 6:8, while 0.5 turns it into 1.5:2; the proportion stays unchanged because both sides use the same nonzero factor.

• Simplify first to expose the basic proportion.
• Multiply both terms by the same value.
• Convert unlike measurement units before comparing them as a ratio.

Limitations and common mistakes

• Decimal ratios may require scaling before an exact integer simplification is meaningful.
• A zero second term cannot be interpreted as an ordinary division rate.

Common questions