Math Calculator

Ratio Calculator

Simplify a ratio to lowest terms or scale it to a target value.

8:12 simplifies to 2:3

2:3

Decimal equivalent
0.6667

How it works

A ratio compares two quantities. "Simplify" reduces a ratio like 8:12 to its lowest terms (2:3), the same way you'd simplify a fraction. "Scale" keeps the same proportion while changing one side to a target number — useful for resizing a recipe or a scale drawing.

Formula

Simplify: divide both sides by their greatest common divisor
Scale: multiply both sides by (target ÷ original first value)

Example

Simplifying 8:12 gives 2:3 (both divided by 4). Scaling 2:3 so the first value becomes 10 gives 10:15.

Frequently asked questions

How is a ratio simplified?

Both numbers are divided by their greatest common divisor (GCD) — the largest number that divides evenly into both. 8:12 has a GCD of 4, so dividing both sides by 4 gives 2:3.

What's a real example of scaling a ratio?

A recipe ratio of 2 cups flour to 3 cups water, scaled to make 10 cups of flour, needs 15 cups of water — same proportion, larger batch.