Narrate 10 slides: one Sume TTS job or ten, and what rounding costs

A 10-slide explainer with one short line per slide is a common narration job. Sume TTS charges $0.0475 per 1,000 characters, rounded up to the next cent for each job, with a one-cent minimum. An 80-character slide line costs only 0.38 cent of audio, but a job has to be paid at no less than 1 cent. Ten of them is $0.10. The same 800 characters as a single job is $0.04.

Pricing the two layouts

Why you might still split

One job is cheapest, but it gives you one audio file. To start each slide's audio at a known time, you either need the segment boundaries inside the file or one file per slide. Sume's TTS can emit sentence-level segments for timing; ten jobs give you ten independent files you can retake one at a time without touching the rest, which is the real reason to pay the extra $0.06.

Rule of thumb

• Slides whose lines are under about 210 characters round to the one-cent minimum each, so a one-line-per-job layout costs a cent a line.
• If you retake often, a per-slide job saves regenerating the others.
• If the narration is one continuous read, send one job. The cap is 20,000 characters, far above a 10-slide deck.