OpenAI tts-1 at $15 per 1M characters vs Sume's rate for 1,000 scripts

OpenAI's pricing page lists tts-1 at $15 per 1 million characters and tts-1-hd at $30, which is $0.015 and $0.03 per 1,000 characters. Sume's text to speech is $0.0475 per 1,000 characters. A batch of 1,000 scripts of 500 characters is 500,000 characters, so it costs $7.50 on tts-1, $15.00 on tts-1-hd and $23.75 on Sume, before Sume's 5.5% agent fee that applies by default.

OpenAI figures are from its pricing page, read 2026-10-01; the Sume rate is from the rate card in the API reference. The page also lists a token-priced gpt-4o-mini-tts, which is not converted to characters here.

How do I compare per-million and per-thousand prices?

Divide the per-million price by 1,000. $15 per million is $0.015 per thousand. Then multiply by your character count in thousands.

How many characters is a typical script?

About 450 to 500 characters is a 30-second voiceover at a normal pace; a 60-second script is near 1,000. Count your own scripts, since the total scales with them. Sume's TTS Router takes up to 20,000 characters per request.

What else changes the real cost?

Rate is only the first line. Retries after a failed or rejected script, voices that need a different tier, and the agent fee all move the total. Sume reports usage.cost on every finished job and GET /v1/usage over time, so run 20 scripts and extrapolate from the measured average.