Playcut v2 is coming MCP · Actor v2 · & much more
Free Tool

Aspect Ratio Calculator

Pick a platform preset or set a custom ratio. Calculate exact pixel dimensions for any AI video output size.

:
16:9
1920 × 1080
pixels
16:9 preview
Match the platform: Veo and Imagen output tighter when you generate at the target aspect ratio rather than cropping later. Pick the preset that matches your final platform — TikTok 9:16, YouTube 16:9, Instagram 1:1 or 4:5.

Why Aspect Ratio Matters for AI Video

AI video models like Veo, Pika, and Kling generate tighter, more coherent motion when you target the final aspect ratio at generation time — rather than generating wide and cropping. The framing is built into the take.

Common Ratios

  • 9:16 (vertical) — TikTok, Instagram Reels, YouTube Shorts
  • 16:9 (landscape) — YouTube, X, LinkedIn, Facebook
  • 1:1 (square) — Instagram feed, profile
  • 4:5 (portrait) — Instagram feed (vertical)
  • 21:9 (cinematic) — Anamorphic widescreen, film

Platform-by-platform sizing rules in 2026

Aspect ratios are the easy part; safe zones and platform-specific specs are where most campaigns waste credits. We test every spec quarterly across the Playcut studio, and the rules below are current as of Q2 2026.

  • TikTok. 9:16 at 1080×1920 is the canonical ratio. The platform applies a roughly 7% top crop and a 12% bottom crop for the username and caption overlays, so keep faces and product labels at least 100 pixels inside those edges. Duration sweet spot for organic reach: 21-34 seconds. Spark Ads accept up to 60 seconds. Higher bitrate uploads (8-12 Mbps) outperform default-compressed videos on the For You feed.
  • Instagram Reels. 9:16 at 1080×1920 again, but the top safe zone is tighter (about 14% reserved for the header) and the bottom safe zone is wider (about 20% for caption and CTA). Reels under 90 seconds get prioritized in feed; Reels above that count as standard video posts with lower distribution. Audio must be licensed or uploaded by you — AI voiceovers count as your own audio.
  • YouTube Shorts. 9:16 at 1080×1920, cap 60 seconds. YouTube does not apply persistent UI overlays during full-screen Shorts playback, so the safe zone is forgiving — but if your Short pulls long-form discovery, viewers may watch in a preview window where the top 18% is hidden behind the channel header.
  • YouTube long-form. 16:9 at 1920×1080 minimum; 4K (3840×2160) earns higher CPMs and stronger algorithmic placement. Generate at 16:9 — if you ever need a cinematic letterbox, add the bars in post rather than generating at 21:9 and risking bottom-cropping faces in player thumbnails.
  • Instagram feed. 1:1 at 1080×1080 is still the safest default for multi-image carousels. 4:5 at 1080×1350 fills more screen on mobile and has been the better-performing ratio for single-image posts since the 2024 algorithm change. Use 4:5 unless your composition strictly needs square framing.
  • X (Twitter). 16:9 at 1280×720 minimum, 1920×1080 preferred. X compresses aggressively — generate at higher resolution than you need and let the platform handle the downscale rather than uploading 720p natively.
  • LinkedIn. 16:9 at 1920×1080 for landscape, 1:1 at 1080×1080 for feed, 9:16 at 1080×1920 for Stories. LinkedIn's autoplay starts muted, so the first three seconds need to land visually without sound.

Cinematic ratios for narrative work

When you're generating for a film festival, a YouTube cinematic-essay piece, or a branded short-form film, the platform-default ratios stop applying. 21:9 (2.39:1) is the modern anamorphic standard and looks correct when delivered at 3840×1600 for 4K or 2048×858 for 2K. 1.85:1 ("flat") is the other theatrical standard — 1920×1037 for HD masters. AI video models like Veo render 21:9 natively when you request it in the prompt; rendering at 16:9 and letterboxing in post is technically possible but it wastes the top and bottom 24% of every frame's compute budget.

Aspect Ratio Calculator FAQ

Which AI video models support which ratios?

Veo 3 natively supports 16:9, 9:16, and 1:1. Veo 3.1 added 4:5 and 21:9. Kling 2.0 supports 16:9 and 9:16 only. Pika 2.0 supports all common ratios but quality drops noticeably outside 16:9 and 9:16. Runway Gen-4 supports a wider matrix including custom dimensions. For consistent multi-platform output, generate in the platform's native ratio rather than cropping in post.

Should I generate in 4K and downscale, or generate at platform-native resolution?

For paid social and short-form, generate at platform-native resolution (1080×1920 for TikTok/Reels, 1920×1080 for YouTube). Generating at 4K and downscaling costs 3-4× the credits and the additional detail is invisible after platform compression. For long-form YouTube and theatrical work, generate at 4K. For brand-website hero video, generate at 1080p and let the CDN deliver responsively.

What's the right ratio for an in-product demo?

16:9 at 1920×1080. Product demos that live inside a landing-page hero or a YouTube long-form work best in landscape. The exception is a TikTok/Reels demo cut, where 9:16 is required and the screen-recording aspect needs to be re-blocked to vertical anyway (zooming the relevant UI, not just cropping).

What size should social share images and favicons be?

Open Graph share cards are 1200×630 (1.91:1) — the free OG image generator builds one with your title and brand colors directly in the browser. Favicons are square: export 512×512 and let the free favicon generator produce the full 16/32/180/512 icon set from a single source image. Once an image is the right size, the free image compressor shrinks the file so the page stays fast.

How do I keep faces and logos out of the safe-zone crop?

Use the framing slot in the Veo Prompt Builder to specify "subject's face in the upper third, kept above the 1080×1920 platform overlay zone" or equivalent. AI models respect framing instructions in the prompt — but only if you give them the instruction in those words.

Want the full studio?

Playcut handles aspect ratios across Veo, Imagen, and Gemini natively — pick the ratio per generation. Start your 7-day trial.