Ratio Calculator
Ratio conversion and solver — enter known values, auto-compute the unknown.
Ratio Calculation
Given A : B = C : D, fill any three values to auto-calculate the fourth
Common Ratio Reference
Golden Ratio
Common in nature and art
1 : 1.618
4:3
Traditional screen ratio
4 : 3
16:9
Widescreen standard
16 : 9
21:9
Ultrawide cinema ratio
21 : 9
1:1
Square ratio
1 : 1
3:2
Classic photo ratio
3 : 2
A4 Paper
ISO 216 standard paper ratio
1 : 1.414
Human Body
Da Vinci's Vitruvian Man
1 : 1 (wingspan ≈ height)
Usage Instructions
Features
Ratio calculator with three modes: basic ratio solver (A:B=C:D, fill 3 find 1), scale by ratio, and value-percentage conversion, plus common ratio reference.
Steps
In 'Basic Ratio' tab fill any three values to auto-solve the fourth → in 'Scale by Ratio' enter original and factor → in 'Percentage' tab convert between value and percentage; click 'Reset' to clear.
Notes
All calculations run locally in the browser using BigNumber for precision. Basic ratio requires at least three values to solve. Results are for reference only.