Example
1920 × 1080 → 16:9
Aspect Ratio Calculator
Calculate the aspect ratio and missing dimensions of any image instantly in your browser. Free online aspect ratio calculator for 16:9, 4:3, and more.
Enter the values below, then press Calculate (or press Enter). The calculator updates your results instantly. Try different values to see how your inputs change the outcome.
- Width (px or units) — enter a numeric amount.
- Height (px or units) — enter a numeric amount.
- Target ratio (optional) — enter a choice from the options.
- Review your results — the key output is highlighted, with supporting figures below.
Loading calculator…
Results
Dimensions & ratio
| Detail | Value |
|---|---|
| Width | |
| Height | |
| Aspect ratio | |
| Decimal ratio |
What is this calculator for?
Determine an image’s aspect ratio and recompute dimensions toward a target ratio like 16:9.
How to Use This Calculator
Enter the values below, then press Calculate (or press Enter). The calculator updates your results instantly. Try different values to see how your inputs change the outcome.
- Width (px or units) — enter a numeric amount.
- Height (px or units) — enter a numeric amount.
- Target ratio (optional) — enter a choice from the options.
- Review your results — the key output is highlighted, with supporting figures below.
What You'll Need
- Width (px or units)
- a numeric amount range 1–∞ · optional
- Height (px or units)
- a numeric amount range 1–∞ · optional
- Target ratio (optional)
- a choice from the options (Keep current dimensions, 16:9, 4:3, 3:2, 1:1, 21:9) · optional
About This Calculator
An aspect ratio is the proportional relationship between width and height, written as two numbers (e.g. 16:9).
This calculator reduces your dimensions to their simplest ratio and, if you pick a target ratio, scales one dimension so the image matches it while keeping the other fixed. The output shows the ratio alongside the resulting width and height.
Calculation runs entirely in your browser.
Worked Examples
Frequently Asked Questions
What are the most common ratios?
16:9 (widescreen video), 4:3 (older displays), 3:2 (photography), 1:1 (square social), and 21:9 (ultrawide).
Can I compute a missing dimension?
Yes — leave either width or height blank, choose a target ratio, and the tool fills in the other value so the image matches that ratio.