Ratio Calculator — Simplify, Scale, and Solve
Simplify any ratio a:b to lowest terms, get the decimal / percentage / reciprocal, and solve for a missing side when scaling proportionally.
Runs 100% in your browser — nothing is uploaded.
:
Simplified ratio
16 : 9
- As decimal: 1.777778
- As percentage: 177.7778%
- Reciprocal: 9 : 16
Scale the ratio
If A becomesthen B becomes:0
Frequently asked
How is the ratio simplified?
Both numbers are divided by their greatest common divisor (Euclidean algorithm). 12:18 becomes 2:3.
What does the reciprocal mean?
The ratio flipped: 2:3 becomes 3:2. Useful when swapping the roles of the two quantities.
How does "solve for" work?
Enter a ratio (e.g. 2:3) and one known value on either side — the calculator scales proportionally to fill in the other. Handy for recipe scaling, mixing paints, and aspect-ratio math.
Related tools
- Percentage CalculatorEvery percentage calculation in one place: X% of Y, X is what % of Y, change fro
- Universal Unit ConverterConvert between units across 8 dimensions: length, mass, volume, time, area, dig
- GPA CalculatorCalculate your weighted GPA across any number of courses. Supports 4.0, 4.3, and
- Age CalculatorEnter a date of birth to see age in years, months, days, hours, minutes, and sec
- BMI CalculatorCalculate your Body Mass Index (BMI) in metric or imperial units. Shows category
- Body Fat Calculator (US Navy)Estimate body fat percentage using the US Navy tape-measure method. Needs only w