Runway Seedance 2 Fast at 29 credits a second vs Sume token math

Runway lists Seedance 2 Fast at 29 credits per second, which is $0.29 at $0.01 per credit. The guide gives one credit value for the model, not a table by resolution. Sume prices seedance-2-fast by video tokens. For a 10 second 720p 16:9 clip, that is 216,000 tokens, which is about $3.02 on Sume against $2.90 on Runway. At 480p the Sume price is lower.

The token formula

Sume's pricing code counts video tokens as (width x height x seconds x 24 fps) / 1024. The rate card for seedance-2-fast lists $0.0112 per 1,000 video tokens, and Sume bills list x 1.25, which is $0.014 per 1,000 tokens. The 720p 16:9 frame is 1280 x 720, and the 480p 16:9 frame is 864 x 496.

Worked example

Worked example for the 720p, 10 s row: 1280 x 720 = 921,600 pixels. 921,600 x 10 x 24 = 221,184,000. Divided by 1024 gives 216,000 tokens. At $0.0112 per 1,000 tokens that is 216 x $0.0112 = $2.4192, and times 1.25 is $3.024.

Which is cheaper

Treating Runway's $0.29 per second as flat, Sume costs less at 480p at every length in the table. At 720p it costs more than Runway at all three lengths, by about 4% ($1.2096 against $1.16, $3.024 against $2.90, $4.536 against $4.35). Sume lists seedance-2-fast at 480p and 720p only, for 4 to 15 seconds.

Runway's web plans use different units: Seedance 2.0 Fast is 116 credits per 4 seconds there, which is also 29 credits per second. The live Sume rate is pricing_skus on GET /v1/videos/models; check it before you plan spend, because the rate card can change.