Ratio Calculator

Two jobs in one tool: reduce a ratio like 16:10 to something readable, or scale a known ratio up and down to find the number you are missing.

Notes

  • Decimal ratios are accepted but only whole-number ratios can be reduced, so 2.5 : 4 is reported as entered.
  • Zero is rejected in either position, because a ratio with a zero part has no meaningful proportion.

Common questions

What is the difference between a ratio and a fraction?
A ratio compares two parts to each other (2 : 3), while a fraction compares one part to the whole (2/5). The share percentages here bridge the two.
How do I scale a recipe with three ingredients?
Solve one pair at a time using the same scale factor. Once you know the factor, multiply every ingredient by it.