720x1280 vs 1080x1920 for a 60 s Short: 40 MB vs 63 MB

At YouTube's listed upload bitrates, a 60 second Short is about 40.38 MB at 720p and 62.88 MB at 1080p, once 384 kbps stereo audio is added. The 1080p file is about 56% larger. YouTube's encoding page (read 2026-10-08) lists 5 Mbps for 720p and 8 Mbps for 1080p SDR at a standard frame rate. These are YouTube's recommended upload rates, and they are used here only to plan sizes.

The arithmetic

Video plus audio: 5 + 0.384 = 5.384 Mbps at 720p, and 8 + 0.384 = 8.384 Mbps at 1080p. Over 60 seconds that is 323.04 and 503.04 megabits. Divide by 8: 40.38 MB and 62.88 MB in decimal megabytes. The gap is 22.5 MB.

Setting the size in Sume

Timeline 1.0 defaults to 1080x1920. For 720x1280, send an output block with width 720 and height 1280. Both are even integers inside the 256 to 2160 range the docs allow. The price does not depend on size: Timeline bills $0.10 per ceil output minute, so both cases are $0.10.

{
  "audio": { "url": "https://media.sume.com/artifacts/artf_demo/voice.wav", "duration_seconds": 60 },
  "video": [
    { "source_url": "https://media.sume.com/artifacts/artf_demo/clip.mp4", "start": 0, "duration": 60 }
  ],
  "output": { "width": 720, "height": 1280 }
}

Which one to pick

The Shorts page caps resolution at 1080p and does not say anything about 720p, so both sizes are inside the cap. Pick 1080x1920 unless upload time matters more than detail. Sume does not take a bitrate, so the file sizes above are plans, not guarantees; read the byte count of the result. Related: the 3 minute size arithmetic and the 1080p default.

When 720p is the right call

Pick 720x1280 when the clip is mostly graphics or text that stays legible at that size, when the source itself is 720p so a larger output adds nothing, or when upload time on a slow connection matters. A 22.5 MB saving per 60 second Short adds up over a batch: 15 Shorts save 337.5 MB.

Pick 1080x1920 when the source is sharper than 720p and detail matters, such as product close-ups. The Shorts page caps resolution at 1080p, so there is no reason to go above it. The Timeline price is the same either way, at $0.10 for a 60 second render.

• 15 Shorts at 720p: 15 x 40.38 = 605.7 MB.
• 15 Shorts at 1080p: 15 x 62.88 = 943.2 MB.
• Difference: 337.5 MB.

Planning a month

For a channel that posts 20 Shorts of 60 seconds a month, the Timeline cost is 20 x $0.10 = $2.00 at either size. Only the file sizes differ: 20 x 40.38 = 807.6 MB at 720p against 20 x 62.88 = 1,257.6 MB at 1080p. The difference of 450 MB is the monthly upload saved.