Calculator · 100% free, no signup · Updated May 2026
Convert any video size to TikTok, Reels, Shorts, or square.
A free aspect-ratio reference and converter for video creators. Maps every major platform's native aspect ratio (TikTok/Reels/Shorts 9:16, YouTube 16:9, LinkedIn 1:1, X 16:9 or 1:1) and outputs safe-zone overlays so your text and faces don't get cropped on any platform.
Enter your source resolution (e.g. 1920×1080), pick the target aspect ratio, and get the new dimensions plus an FFmpeg `crop=` filter you can paste straight into a terminal. No upload — pure math, runs entirely in your browser.
Target size
608 × 1080
Crop window
x=656, y=0, w=608, h=1080
ffmpeg -i input.mp4 -vf "crop=608:1080:656:0" output.mp4
Who this is for
Video editors, podcasters, and creators who need to reframe a horizontal recording to TikTok / Reels / Shorts without firing up Premiere or DaVinci Resolve.
The problem this solves
Reframing video by hand is fiddly: you have to math out the crop window, hold the subject center-frame, and not introduce letterboxing. The converter does the math and outputs an FFmpeg command — paste it, render, done.
Approximately 73% of mobile social video is watched in vertical orientation; non-vertical video on mobile-first platforms (TikTok, Reels, Shorts) loses 40-60% of impression volume vs natively-shot vertical content.
Source: Wistia Mobile Video Report 2025 + Buffer State of Social 2025
How to use it
- 01
Enter your source resolution
Width × height of the original video. Most cameras record at 1920×1080 or 3840×2160.
- 02
Pick a target aspect ratio
9:16 for TikTok / Reels / Shorts, 1:1 for Instagram square, 4:5 for Instagram portrait, 16:9 for YouTube.
- 03
Choose a crop anchor
Center is safest; left / right shift if your subject lives there. Smart-crop is a Clipflow Pro feature that tracks the face.
- 04
Copy the FFmpeg command
A ready-to-paste `ffmpeg -i input.mp4 -vf "crop=…" output.mp4` snippet appears below the result.
What you get
- ✓ Exact target width × height for the chosen aspect ratio
- ✓ Crop window coordinates (x, y, w, h) for FFmpeg or Premiere
- ✓ Copy-paste FFmpeg command with the right filter chain
- ✓ Preview rectangle so you can sanity-check the crop window
Frequently asked
What's the right aspect ratio for TikTok?
9:16 (vertical). 1080×1920 is the native upload spec. Anything else gets letterboxed and loses reach.
Can I post the same video on TikTok and YouTube?
Only if you shoot vertically (9:16). YouTube Shorts accepts 9:16 natively; long-form YouTube accepts vertical but pillar-boxes it (black bars). Always shoot vertical for cross-platform.
What's the safe zone on a 9:16 video?
Center 70% horizontally and 60% vertically. TikTok's UI overlays (username, caption, sound) cover the bottom 25% and right edge. Keep critical visuals in the safe zone.
Does Instagram Reels use the same ratio as TikTok?
Yes, 9:16. But Reels safe-zone is slightly different — Instagram's UI overlays the bottom 15% instead of 25%. The converter flags both.
Can Clipflow auto-convert my horizontal video to vertical?
Yes. Clipflow's auto-reframe detects faces and key motion, then crops to 9:16 dynamically per frame. No manual reframing needed.
Related tools
Author + maintainer
Adrian Berisha — Founder of Clipflow. Indie SaaS builder shipping creator tools full-time since 2024. All tools and benchmarks on this page are reviewed quarterly. Last review: May 2026.
@clipflow on X · LinkedIn · hi@clipflow.to
Want this baked into your workflow?
Clipflow runs the whole repurposing pipeline — clip-finder, brand-voice captions, scheduler, multi-platform publish — for free on the Starter plan.
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