Ratio Calculator
Work with ratios in three ways: simplify A:B, scale A:B to a target for A or B, or solve a proportion (A:B = C:D).
Simplify A:B
Privacy: calculations run locally in your browser. No inputs are stored or transmitted.
How it works
Simplify: divide A and B by their GCD (for integer ratios).
Scale: scale = target ÷ chosenSide, then A′ = A×scale, B′ = B×scale.
Proportion: A:B = C:D ⇒ A×D = B×C (cross multiplication).
Examples
- 10:15 → 2:3
- 2:3 scaled to A=10 → 10:15
- 2:3 = 10:D → D = 15
When to use this tool
This tool is designed for quick, practical tasks such as everyday calculations, data formatting, or simple conversions. It is best used when you need fast results without installing software or using complex tools.
When to use
- Quick checks or one-time calculations
- Validating or converting data before using it elsewhere
- Simple tasks that do not require advanced software
When not to use
- Critical financial, legal, or medical decisions
- Large-scale or automated processing
- Situations requiring guaranteed precision beyond basic validation
Always review results before using them in important contexts.
About this tool
This tool helps you perform quick utility operations directly in your browser. It runs entirely in your browser without sending data to a server.
You can use this tool when handling simple tasks without installing additional software. The results should be interpreted as a processed output based on your input data.
FAQ
- What is a ratio?
A ratio compares two quantities using division, often written as A:B or A/B.
- How do you simplify a ratio?
Divide both parts by their greatest common divisor (GCD). Example: 10:15 → 2:3.
- How do you scale a ratio to a target value?
Pick which side to target (A or B), compute scale = target ÷ currentSide, then multiply both sides by scale.
- What is a proportion (A:B = C:D)?
A proportion states two ratios are equal. You can solve for a missing value using cross multiplication.
- Can ratios use decimals?
Yes. This tool supports decimals and will also show an approximated simplified integer ratio when possible.
- What if one side is zero?
A ratio like 0:5 is valid. But 5:0 implies division by zero when interpreted as A/B, so some operations (like percent forms) are undefined.