Ratio Calculator
Simplify a ratio, compare its parts, and see the decimal relationship between two non-zero values.
How it works
Scale decimal inputs to whole numbers, find the greatest common divisor, then divide both parts by the same value.
Formula / calculation method
Scale decimal inputs to whole numbers.Find the greatest common divisor (GCD).Divide both parts by the GCD to obtain the simplified ratio.
Worked examples
- 12 : 18 simplifies to 2 : 3 because both parts divide by 6.
- 1.5 : 2.25 also simplifies to 2 : 3 after scaling both values before reduction.
How to simplify a ratio
Enter the two parts of the ratio in the same order they appear. Solveberry scales decimal inputs when needed, finds the greatest common divisor, and divides both parts by that value.
- Keep both quantities in compatible units before simplifying.
- Divide both parts by the same greatest common divisor.
- Check the result by multiplying both simplified parts by the same scale factor.
Continue: Compare ratio and percentage formulas.
When this tool helps
Use it for recipe scaling, map scales, proportions, mixture comparisons, dimensions, and any situation where two quantities should be expressed in their simplest relationship.
Related calculations: percentage calculator, percentage change, and percentage increase or decrease.
Browse this topic: Percentage, Ratio & Finance Calculators · Percentage & Finance Formula Guide.
Quick reference: Ratio simplification examples
| Input | Result |
|---|---|
| 12 : 18 | 2 : 3 |
| 10 : 25 | 2 : 5 |
| 1.5 : 2.25 | 2 : 3 |
Accuracy and definitions
Ratios are reduced by converting decimal inputs to integers at up to six decimal places, then applying a greatest-common-divisor reduction. Both parts must be non-zero.
Methodology & verification
- Method
- Scale decimal inputs to whole numbers, find the greatest common divisor, then divide both parts by the same value.
- Verification
- The displayed formula is cross-checked against Solveberry regression cases before release. Calculator inputs and results stay in the browser.
- Last reviewed
- 2026-09-05
Results are calculated locally in your browser. Optional analytics do not include calculator input values or results.
Common questions
Can a ratio contain decimals?
Yes. Solveberry scales decimal inputs before reducing them, so values such as 1.5 : 2.25 can simplify cleanly.
Why are zero values rejected?
A two-part ratio with a zero part does not fit this tool’s reduction model. Use a purpose-specific proportion or rate calculation instead.
Can I use decimal values?
Yes. The calculator accepts decimal values where they are mathematically valid for the selected calculation.
How should I verify an important result?
Use the displayed formula to reproduce the calculation independently, especially before making financial, legal, engineering or other consequential decisions.