Aspect Ratio Calculator
Calculates matching width or height dimensions for a chosen aspect ratio like 16:9 when resizing.
100% FreeRuns in your browserBasic
Enter Values
Enter your values and press Calculate to see results.
How to use this calculator
- Enter a width and height to get the simplified ratio.
- Optionally enter a new width to scale the height proportionally.
How it works
The ratio is simplified by the greatest common divisor; a new height = new width × original height ÷ original width.
Worked example
1920 × 1080. = 16:9; a new width of 1280 gives 720 px high.
Tips
- Runs entirely in your browser. Your input is not uploaded or stored.
Frequently asked questions
Common ratios?
16:9 (video/screens), 4:3 (older displays), 1:1 (square), 3:2 (photos).
Privacy?
Runs entirely in your browser. Your input is not uploaded or stored.
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Cite this tool
Zerdly. (2026). Aspect Ratio Calculator. Retrieved from https://www.zerdly.com/tools/aspect-ratio-calculator/
Tip: Enter any known values to calculate the remaining results.
All calculations run in your browser. Your inputs are never saved or transmitted.