Aspect Ratio Calculator
Compute screen dimensions for a target ratio.
Your files stay on your device
This tool processes everything locally in your browser. Nothing is uploaded to a server.
📝 About Aspect Ratio Calculator
Aspect Ratio Calculator works out the height that matches a given width for a chosen screen ratio. Pick one of the presets — 16:9, 9:16, 4:3, 3:4, 1:1 or 21:9 — type a width in pixels, and the matching height appears instantly, rounded to the nearest whole pixel.
Game developers use it to plan render resolutions, UI canvases and store screenshots; video creators use it for thumbnails and vertical shorts; web designers use it for banners and embedded players. For example, a width of 1280 at 16:9 gives 720, while 1080 at 9:16 gives 1920 for a portrait mobile screen.
Below the calculator you’ll find a quick reference of common game and device resolutions, including 1080p, 720p, mobile portrait, a modern iPhone (about 19.5:9), iPad (4:3) and square 1:1. Modern phones are taller than 16:9, so it’s worth testing your layout on several ratios or using safe areas. The calculation is instant and runs entirely in your browser.
📘 How to use
- 1
Choose a ratio
Click one of the ratio buttons, such as 16:9 or 9:16.
- 2
Enter the width
Type the target width in pixels in the Width field.
- 3
Read the height
The matching height is shown instantly, and you can compare it with the common resolutions listed below.
❓ FAQ
Can I enter a custom ratio like 19.5:9?
The calculator currently offers six presets: 16:9, 9:16, 4:3, 3:4, 1:1 and 21:9. Common device resolutions such as the iPhone’s are listed below for reference.
Why is the height rounded?
Screens and images use whole pixels, so the result is rounded to the nearest integer. Choosing a width divisible by the ratio’s first number gives an exact result.
Which ratio should I use for a mobile game?
16:9 (or 9:16 for portrait) is a common baseline, but many phones are around 19.5:9 or taller, so design with flexible layouts and safe areas.