$250 credit cap on Wan 3.0: how many 9-second clips fit

A $250 credit cap buys 111 Wan 3.0 clips of 9 seconds at 1080p on Sume, 222 at 720p, or 444 at 480p. Each tier costs $0.0625, $0.125 and $0.25 per output second, so a 9-second clip is $0.5625, $1.125 or $2.25, and every tier lands on exactly $249.75 with $0.25 left over.

How the cap divides

Take the per-clip price and divide $250 by it, rounding down because you cannot submit a fraction of a clip. At 1080p: $250 / $2.25 = 111.1, so 111 clips. At 720p: $250 / $1.125 = 222.2, so 222. At 480p: $250 / $0.5625 = 444.4, so 444.

Wan 3.0 accepts 2-30 seconds on Sume, so 9 seconds is inside the range. Each resolution step doubles the per-second price (0.0625, 0.125, 0.25), which is why the clip counts halve each time.

Mixing tiers inside one cap

A single tier is rarely the right plan. A common split is to draft at 480p and finish winners at 1080p. Say you draft 200 clips at 480p: 200 x $0.5625 = $112.50. That leaves $137.50, which pays for 61 finals at 1080p (61 x $2.25 = $137.25) with $0.25 left.

The mixed plan gives you 200 drafts and 61 finals for the same $250 that otherwise buys 111 finals and no drafts. Whether that is better depends on your hit rate: if one draft in three is usable, 200 drafts yield about 66 candidates for 61 finals.

• 200 drafts at 480p = $112.50
• 61 finals at 1080p = $137.25
• Total = $249.75

What happens at the cap

Sume checks the balance before accepting a job. If the balance cannot cover the requested generation the API returns 402 with the code insufficient_credits. A job that fails after submission is refunded before capture according to the catalog's reservation policy, so failed clips do not eat into the count above.

Treat the cap as a local number as well. Subtract each job's list price from a running total in your own code and stop at the cap, instead of waiting for the first 402. That keeps a half-finished campaign from stalling on a hard error.

A second scenario

Hold back a reserve. If you set aside $25 of the $250 for retakes, $225 remains for first-pass clips: at 1080p that is $225 / $2.25 = 100 clips. At 720p it is 200 clips, and at 480p it is 400. A 10 percent reserve costs 11 clips at 1080p, which is usually cheaper than stopping a campaign when the balance runs out.

Check before you commit

Run one 9-second clip at each tier first: $0.56, $1.13 and $2.25 is $3.94 for the three. The catalog lists the live per-second prices at api.sume.com/v1/catalog, and the model limits are on the video docs pages, so you can confirm the numbers above before sizing a larger run.

Reproduce the numbers

Open https://api.sume.com/v1/catalog, which needs no key, and find the entry for the product. Each model_pricing row carries price, unit, pricing_basis and the estimated, minimum and maximum cents. Multiply the unit price by your quantity and round only at the end. The catalog also has applied_* fields that include an agent fee of 550 basis points; the figures in this post use the base prices.