Video aspect ratio calculator
Find the exact pixel size for 9:16, 4:5, 1:1 or any ratio, reduce a resolution to its ratio, and see what happens when landscape footage goes vertical.
Runs entirely in your browser. Nothing is uploaded. No signup needed.
Solve width or height
Find the ratio of a resolution
Fit footage into a 1080 x 1920 vertical frame
Menivor renders every video at 1080 x 1920 with captions kept inside the platform safe zones. Make it a finished video free
How to use it
- 1Enter a ratio (such as 9:16) and either a width or a height to get the other side.
- 2Or enter any width and height to see the simplified ratio.
- 3Use the fit check to see how your footage lands inside a 1080 x 1920 frame, padded or cropped.
About this aspect ratio calculator
TikTok, Instagram Reels and YouTube Shorts are all built for 9:16 vertical video at 1080 x 1920 pixels. Uploading anything else means black bars or an automatic crop that can cut off faces, text and products.
This calculator does three jobs. It solves the missing width or height for any ratio (rounded to even pixels, which H.264 and H.265 encoders require), it simplifies a resolution such as 1080 x 1350 to its ratio (4:5), and it shows how a source frame fits a target frame either padded with bars or cropped to fill.
The table below lists the recommended upload sizes for each major short-form placement, including the safe-zone notes that keep your captions clear of platform buttons.
| Placement | Ratio | Pixels | Note |
|---|---|---|---|
| TikTok | 9:16 | 1080 x 1920 | Full-screen vertical. Keep text out of the bottom fifth and the right edge. |
| Instagram Reels | 9:16 | 1080 x 1920 | Grid preview crops to 3:4, so keep the subject centred. |
| YouTube Shorts | 9:16 | 1080 x 1920 | Vertical or square, up to 3 minutes. |
| Instagram feed (portrait) | 4:5 | 1080 x 1350 | Tallest ratio the feed shows without cropping. |
| Square post | 1:1 | 1080 x 1080 | Feeds on Instagram, Facebook and LinkedIn. |
| YouTube (landscape) | 16:9 | 1920 x 1080 | Standard HD; 3840x2160 for 4K. |
Frequently asked questions
- What is the aspect ratio for TikTok, Reels and Shorts?
- 9:16 vertical. The recommended resolution is 1080 x 1920 pixels for all three.
- What is 1080 x 1350 in aspect ratio?
- 4:5. It is the tallest portrait ratio the Instagram feed shows without cropping.
- Why should dimensions be even numbers?
- H.264 and H.265 encode colour at half resolution (4:2:0), so width and height must be divisible by 2. Odd sizes cause export errors or a one-pixel edge.
- How do I turn a landscape video into 9:16?
- Either crop to the centre (fills the screen but cuts the sides) or pad with bars or a blurred background (keeps everything but shrinks it). The fit check here shows the exact pixel sizes for both.
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Skip the busywork: get finished videos
Paste a link or type a topic. Menivor writes the hook and script, records the voiceover, adds footage and word-by-word captions, and renders ready-to-post vertical videos in 1080 x 1920.