TikTok Aspect Ratio Calculator
If you upload a video that is the wrong shape, TikTok will do one of two things: stretch it, or slap black bars on either side. Neither looks good, and neither helps your watch time. This calculator does the boring math for you - punch in your source footage's width and height, or the ratio you're aiming for, and it tells you exactly what dimensions to export at so your video fills the screen the way it's supposed to.
Why aspect ratio actually matters on this app
TikTok was built around one shape: 9:16, vertical, full-screen. That is not a style preference - it is the shape of a phone held upright, which is how something like 94-95% of TikTok's traffic is actually watched. When you upload something a different shape - a horizontal 16:9 clip from a DSLR, or a square 1:1 Instagram crop - TikTok has to compress it into that vertical frame somehow, and that means padding, cropping, or shrinking the parts of your video that used to be full-bleed.
The practical numbers to know:
- Native/recommended: 1080 x 1920 pixels, 9:16 ratio. According to the official TikTok video creation specifications, this fills the entire screen natively without letterboxing.
- Also accepted: 1:1 square (1080 x 1080) and 16:9 landscape (1920 x 1080) - both will play, but they will show letterboxing above and below, or on the sides, and generally take up less real estate on the For You feed.
- Minimum resolution TikTok will accept: around 540 x 960. Anything smaller and you are fighting compression and blur on top of the wrong shape.
How to use this calculator
Enter either your existing footage size (say, 1920 x 1080 from a camera) or just tell it the target ratio you want. It'll spit back the crop or export dimensions that keep your subject centered instead of guessing where the edges of a 9:16 frame will land. This matters most for anyone shooting on a "real" camera rather than a phone - that gear defaults to 16:9, and converting it after the fact without knowing the math means either an awkward crop of someone's face or a video that looks tiny and boxed-in on a feed built for full-screen vertical content.
A couple of things worth knowing before you export
TikTok caps out at 1080p regardless of what you upload - so if you're exporting from 4K source footage, there's no benefit to keeping it at 4K; downscale to 1080 x 1920 and save yourself the file size. Also worth remembering: TikTok overlays your username, caption, and action buttons along the right edge and bottom of the screen, so even a perfectly sized 9:16 video should keep important text or faces away from those margins - a correctly-sized frame doesn't help much if the caption bar covers your subject's face anyway.
Official Specifications & References
- Official TikTok Video Guidelines: Authoritative specifications for 9:16 vertical aspect ratio, 1080x1920 resolution, and supported frame rates. Review the TikTok Business Video Creation Specifications.
- Aspect Ratio Video Standards: International telecommunication standard governing pixel aspect ratios and spatial digital video scaling. Review the ITU-T Recommendation H.264.