How do I calculate an aspect ratio?
Divide the width and height by their greatest common divisor to get the
smallest whole-number ratio. For 1920 × 1080 the divisor is 120, so the ratio
is 16:9. Enter any width and height above and the reduced ratio
appears instantly.
What is the aspect ratio of 1920×1080?
1920 × 1080 is 16:9 — the standard widescreen ratio for HD and 4K video, most monitors, and YouTube. 1280 × 720 and 3840 × 2160 are also 16:9.
How do I resize while keeping the same aspect ratio?
Set the original size to define the ratio, then type a new width in the Scale row — the height fills in automatically (and vice versa). This keeps images and videos from stretching or squashing.
What are common aspect ratios?
- 16:9 — widescreen video, monitors, YouTube.
- 4:3 — older displays, many photos, slides.
- 21:9 — ultrawide monitors and cinematic video.
- 1:1 — square, common for social posts and avatars.
- 9:16 — vertical video for Reels, Shorts, and TikTok.
Common use cases
- Resizing images or video frames without distortion.
- Picking export dimensions for a target screen or platform.
- Working out letterboxing or canvas sizes for design work.