Ratio & Aspect Ratio Calculator
Solve proportions, calculate screen aspect ratios, and simplify numbers to lowest terms.
Enter any 3 values and leave one blank to solve for the missing variable.
How to Use Ratio Calculator
- Select your tab: 'Proportion Solver', 'Aspect Ratio Scaler', or 'Simplify Ratio'.
- In Proportion mode, fill in any 3 numbers and leave the unknown blank to solve.
- In Aspect mode, enter width and height or pick a preset (16:9, 4:3, 1:1, 9:16).
- Adjust new dimensions to see scaled measurements with locked aspect ratio.
Technical Specifications & How It Works
Proportion solving relies on the fundamental equality A/B = C/D, meaning cross multiplication yields A × D = B × C.
Ratio simplification finds the Greatest Common Divisor (GCD) using the Euclidean algorithm to reduce values to lowest whole integers.
Runs client-side with zero network latency and complete privacy.
Frequently Asked Questions
What is an aspect ratio?
An aspect ratio expresses the proportional relationship between width and height (e.g. 16:9 for modern widescreen displays).
How do I simplify a ratio?
Divide both numbers by their Greatest Common Divisor (GCD) until no common integer factor remains.
What is the aspect ratio of 1920x1080?
1920×1080 simplifies to exactly 16:9 with a decimal value of 1.778:1.