Ratio Simplifier – Reduce A:B to Lowest Terms

A ratio compares two quantities, and simplifying it divides both sides by their greatest common divisor without changing the relationship. For 48:36, the GCD is 12 — Euclid: 48 mod 36 = 12, 36 mod 12 = 0 — so the simplest form is 4:3. Decimal ratios clear their places first: 0.75:1.5 multiplies both sides by 100 to 75:150, and dividing by the GCD 75 yields 1:2. The tool works in the other direction too — given 4:3 and a target total of 35 parts, it scales to 20:15, which is how recipes, paint mixes and allocation problems are solved. Percentage conversion is included: 4:3 means 57.14% to 42.86% of the whole, useful when a ratio must be reported as shares.

1. 1

   Enter both parts

   Whole numbers or decimals like 0.75:1.5

2. 2

   Clear decimals if needed

   Multiply both sides by 10 until they are integers

3. 3

   Find the GCD

   Euclid’s algorithm computes the greatest common divisor

4. 4

   Divide and scale

   Reduce to lowest terms, or scale to a required total

• 1

  Simplified ratios keep the same value: 48:36 and 4:3 differ only in units

• 2

  Screen sizes reduce nicely: 1920:1080 = 16:9

• 3

  Scale factor = target total ÷ current total of ratio parts

• Dividing only one side of the ratio, breaking the comparison

• Simplifying 0.75:1.5 to 1:2 by rounding instead of exact division

• Confusing ratio 4:3 with fraction 4/3 of a single quantity

• Scaling by the wrong total — 35 parts needs ×5 of 4:3 (20:15), not ×35