Free Ratio Calculator
Three calculators in one: simplify any ratio to its lowest terms, find the aspect ratio of width × height dimensions, and apply the golden ratio φ — with the full working shown.
How to use
- Pick the calculation type: “Simplify ratio”, “Aspect ratio”, or “Golden ratio”.
- Enter your number(s) and click Calculate.
- See the answer with the full working — the GCD, the division steps, or the φ multiplication.
Frequently asked questions
How do you simplify a ratio?
Divide both parts of the ratio by their greatest common divisor (GCD). For example, the GCD of 12 and 18 is 6, so 12:18 simplifies to (12 ÷ 6):(18 ÷ 6) = 2:3.
What is the aspect ratio of 1920x1080?
16:9. Divide 1920 and 1080 by their GCD (120): 1920 ÷ 120 = 16 and 1080 ÷ 120 = 9.
What is the golden ratio and how do I use it?
The golden ratio is φ ≈ 1.6180339887. Multiply a length by φ for the larger golden section, or divide by φ for the smaller one — a classic proportion used in design and art.
Why are aspect ratios written like 16:9?
An aspect ratio is the width-to-height proportion of a rectangle reduced to lowest terms. 16:9 means the width is 16 units for every 9 units of height — the standard for HD screens.
Is my data sent anywhere?
No — every calculation runs in your browser. Nothing is uploaded or stored.
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