Is ultrawide 21:9 pricier on Seedance 2.5 than 16:9 on Sume?
On Sume, Seedance 2.5 at 21:9 or 4:3 costs a cent or a few more than 16:9, 9:16 or 1:1. A 30-second 720p clip is $17.42 at 21:9 against $17.34.

Slightly. On Sume, a 720p Seedance 2.5 clip at 21:9 costs a cent or a few more than at 16:9, 9:16 or 1:1: $17.42 against $17.34 at 30 seconds. The aspect ratio is not a real cost lever.
The numbers
I ran Sume's Seedance estimator in packages/provider-pricing/src/media-estimators.ts for each ratio at 720p. The three common ratios price identically; 21:9 and 4:3 land slightly higher, which suggests the frame size used for those ratios has a few more pixels. I did not trace the reason beyond the output.
| Seconds | 16:9, 9:16, 1:1 | 21:9 | 4:3 |
|---|---|---|---|
| 4 | $2.32 | $2.33 | $2.33 |
| 10 | $5.78 | $5.81 | $5.82 |
| 22 | $12.72 | $12.78 | $12.80 |
| 30 | $17.34 | $17.42 | $17.45 |
What to do
Pick the ratio for the placement and ignore the price. The premium at 30 seconds is 8 cents for 21:9 and 11 for 4:3, which is under one percent. Resolution and duration are what move the bill: 1080p at 30 seconds is $42.65.
Supported ratios and durations for each model come from the models endpoint described in the Sume video models docs, so check it before relying on 21:9. The ladder for other resolutions is in the 30-second price post.
- 16:9, 9:16 and 1:1 cost the same.
- 21:9 and 4:3 add 1 to 11 cents at these lengths.
- Check supported ratios before you plan.
Does it change a batch?
Over a batch of 100 thirty-second clips at 720p, the 21:9 premium is 100 x 8 cents = $8.00 on a $1,734 bill. Choosing 4:3 instead costs $11.00 more. These are real but tiny, so decide the ratio by where the video will be shown, not by this table.
If you need an exact figure for a mixed-ratio batch, estimate each ratio once and multiply, since the table shows the price differs only slightly by ratio. Rounding is applied per job, so sums of per-job cents are exact.
How these numbers were produced
I read the rate tables in the clone of Sume's repository on 2026-10-06 and called estimateSeedanceProviderCost for seedance-2.5, covering five aspect ratios at four durations. The output fields are billableAmountUsdMicros and billableAmountUsdCents; the tables show the cents.
These are estimates of the billed amount for the stated settings. Anything not in the table, such as a different frame shape, a reference input or a changed quality tier, can change the number, so run the estimate for your own request before a large batch. Where this page and the public API pricing list disagree, the pricing page and the live quote win.
Sources
Related posts
More in Pricing
- Does a reference video cost more on Seedance 2.5? Break-even at 22.5 s
Adding a reference video raises a short Seedance 2.5 quote but lowers a 30-second one. Sume's estimator prices it as 15 extra input seconds at 0.6x.
- Seedance 2 vs 2.5 for 10 seconds: 480p, 720p, 1080p cost
10-second 9:16 clip on Sume: Seedance 2.5 $5.7780 at 720p and $14.2155 at 1080p; Seedance 2 $3.78 and $8.5050.
- Seedance 2 vs 2.5 for 12 seconds: 480p, 720p, 1080p cost
12-second 9:16 clip on Sume: Seedance 2.5 $6.9336 at 720p and $17.0586 at 1080p; Seedance 2 $4.5360 and $10.2060.
- Seedance 2 vs 2.5 for 15 seconds: 480p, 720p, 1080p cost
15-second 9:16 clip on Sume: Seedance 2.5 $8.6670 at 720p and $21.32325 at 1080p; Seedance 2 $5.67 and $12.7575.
Written by Sume