Aspect ratio crop calculator
Type your video's width and height to get the biggest crop for each format, how much of the frame it keeps, and the size it exports at.
Updated November 12, 2026
| Aspect | Largest crop | Frame kept | Export at 1080p |
|---|---|---|---|
| 9:16 | 606 × 1,080 | 31.6% | 1080 × 1920 |
| 16:9 | 1,920 × 1,080 | 100% | 1920 × 1080 |
| 1:1 | 1,080 × 1,080 | 56.3% | 1080 × 1080 |
| 4:5 | 864 × 1,080 | 45% | 1080 × 1350 |
Runs in this browser tab. Nothing you add is uploaded.
What the numbers mean
The largest crop is the biggest box of the target shape that fits inside your frame, rounded to even pixels because video encoders want them. Frame kept is that box's area as a share of the whole picture. Export at 1080p is the size with 1080 pixels on the short side, which is what most vertical and square posts use.
Going from 16:9 to 9:16 keeps under a third of the frame. Going from 9:16 to 16:9 keeps even less. Square and 4:5 sit in between, which is one reason they are a safe middle ground when one video has to work in two places.
Film for the crop you need
If you know the video will end up vertical, keep yourself near the middle of a wide frame and leave room above your head. If it has to work wide and tall, film vertical at the highest resolution your phone allows and crop down for the wide version, or film the two separately.
In the editor
Cutroom AI exports 9:16, 1:1, 4:5 and 16:9 from the same edit. The crop can follow your face, stay centered, or be placed by hand, and zoom keyframes let you push in on a moment. Pro exports up to 2160p.
Questions
Does cropping lose quality?
It keeps fewer pixels. A 1920 by 1080 frame cropped to 9:16 leaves a 606 by 1080 picture, which is then scaled up to 1080 by 1920. Filming in 4K gives the crop more to work with.
Which format should I post?
Use 9:16 for TikTok, Reels and Shorts, 4:5 or 1:1 for feed posts, and 16:9 for YouTube and most websites.
Keep reading
Try it on your own footage.
The editor opens in your browser with no account, and the sample project doesn't use an edit.