Video Aspect Ratio Calculator
Plan sequence, canvas or export dimensions for a video editor. Choose a video ratio and enter one side to calculate the other; this tool does not inspect, convert or encode a video file.
Video dimensions
Popular formats includedFormat preview
Landscape videoPopular video ratios
Common aspect ratios for web video and social platforms.
| Ratio | Typical use | Common size |
|---|---|---|
| 16:9 | YouTube, HDTV, desktop video | 1920 × 1080 |
| 9:16 | TikTok, Shorts, Reels | 1080 × 1920 |
| 1:1 | Square video | 1080 × 1080 |
| 4:5 | Portrait social content | 1080 × 1350 |
| 21:9 | Ultrawide / cinematic | 2520 × 1080 (exact) |
How to calculate video dimensions
- Choose the target ratio based on the final player or placement.
- Enter either the desired width or height. Leave the other field blank.
- The calculator applies the ratio and rounds the missing dimension to a whole pixel.
- Use the result as the sequence, canvas or export dimensions in your video editor.
Aspect ratio determines framing; resolution determines the number of pixels. A higher resolution does not change the shape when both dimensions remain proportional.
From calculated size to a video export
For a vertical sequence at 9:16, entering a width of 1080 gives a height of 1920. Apply both numbers in your editor's sequence or export settings. Check how existing footage fits: changing the sequence size alone does not decide whether the source is cropped or padded.
Resolution is only one export setting. Frame rate, codec, bitrate and audio settings remain decisions for your editor and delivery requirements; this calculator does not validate them. After choosing the frame, use the video file size calculator to estimate storage from bitrate and duration.
Need to choose a shape first? Compare the 16:9 widescreen guide and 9:16 vertical guide, or browse all ratio guides. For an arbitrary ratio or to identify a ratio from two dimensions, use the general aspect ratio calculator.
Resolution and encoder-friendly sizing
Video encoders commonly work with blocks of pixels, so even widths and heights are a practical default. If a custom ratio produces an odd result, rounding to the nearest even number usually introduces only a tiny ratio difference.
Do not add black bars directly to a file unless the delivery specification requires them. YouTube's player adapts to different video ratios and recommends avoiding baked-in padding. See YouTube's aspect ratio guidance.
Crop, reframe or add canvas space?
When source and target ratios differ, choose intentionally. Cropping fills the destination but removes part of the source. Reframing moves the crop to follow the subject. Fitting retains the full source but leaves canvas space that can be filled with a background.
A landscape-to-vertical conversion needs more than a dimension change: titles may need new line breaks, subjects may need tracking and graphics near the sides may disappear. Calculate the geometry with the fit and crop tool before editing.
Frequently asked questions
What ratio should I use for a standard YouTube video?
16:9 is YouTube's standard computer playback ratio, although the player also adapts to square and vertical files.
What ratio should I use for vertical video?
9:16 is the conventional full-screen vertical shape. Confirm the exact requirements and safe areas for the destination placement.
Is 4K always 16:9?
No. “4K” describes a resolution class, not one universal ratio. 3840 × 2160 is the common 16:9 UHD size, while other 4K workflows can use different dimensions.
Why did the calculator round a dimension?
Video dimensions must be whole pixels. The tool rounds fractional results to the nearest integer.
Will this tool convert my video file?
No. It calculates canvas dimensions. Apply them in your editing or encoding software.