Ratio Calculator
Ratios express relationships between quantities. Simplify any ratio to its lowest terms and scale it to any target total instantly.
How It Works
Finds the GCD of both values and divides each by it to get the simplest form. Optionally scales to any target total.
Formula
Simplified = (A ÷ GCD) : (B ÷ GCD)
Scale: multiply each part by (Target ÷ (A+B))
Example
12:18 → GCD=6 → 2:3
Percentages: 40% : 60%
When to Use This Calculator
Use for scaling recipes, mixing solutions, interpreting map scales, or solving ratio problems in math.
Common Mistakes to Avoid
- Confusing ratio with fraction — ratio 3:5 means 3 parts to 5 parts (total 8).
- Not converting decimals to integers first before simplifying.
- Forgetting units in real-world ratios — 1:10 bleach means 1 part bleach to 10 parts water.
Frequently Asked Questions
How to simplify a ratio?
Divide both numbers by their GCD. Example: 24:36 → GCD=12 → 2:3.
What is a 1:1 ratio?
Equal parts — a 50/50 mix.
How to scale a ratio?
Multiply both parts by the same number. 2:3 scaled to 20 total: multiply each by 4 → 8:12.
Can ratios have 3 numbers?
Yes — 1:2:3 means three quantities in those proportions. Total parts = 6.
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Last Updated: July 4, 2026