Find the aspect ratio of an image or screen (16:9, 4:3) and work out a new width or height without distorting it.
Last updated: October 31, 2026
16:9, 4:3 and resizing without distortion
Aspect ratio is the proportion between an image's width and its height. To find the ratio of a 1920 × 1080 image, divide both numbers by their greatest common divisor: that's 120, and 1920 ÷ 120 = 16 and 1080 ÷ 120 = 9, so the ratio is 16:9. To resize while keeping the ratio: • New height = new width × original height ÷ original width • New width = new height × original width ÷ original height Example: scaling a 1920 × 1080 video down to 1280 pixels wide gives a height of 1280 × 1080 ÷ 1920 = 720. Common ratios: • 16:9 — TV, YouTube, most monitors (1280×720, 1920×1080, 3840×2160) • 4:3 — older TVs, some tablets and cameras • 3:2 — cameras, some laptops • 1:1 — square posts • 9:16 — vertical video (Reels, TikTok, Shorts) • 21:9 — ultrawide monitors and cinema If the ratio changes, the picture looks squashed or stretched. When the result has decimals, round to the nearest whole pixel; video encoders usually want even numbers.
Common questions about aspect ratio
16:9. Other common resolutions with this ratio are 1280×720 (HD), 2560×1440 (QHD) and 3840×2160 (4K).
Other tools you may find useful
For example 1920.
For example 1080.
The width you want.