Precise pricing for TTS API

Hi!

Does anyone know how exactly the fees for the TTS API are calculated?

Only the following information is provided:

0.015 / 1000 characters (tts-1)
0.030 / 1000 characters (tts-1-hd)

Is the billing done for every character or for every 1000 characters?

What are the charges for the following queries:

10 characters = ? 999 characters = ?
1001 characters = ? 2500 characters = ?
4096 characters = $?

Is my below calculation correct?

TTS-1 Rate ($0.015 per 1000 characters)

10 characters = $0.015
999 characters = $0.015
1001 characters = $0.030
2500 characters = $0.045
4096 characters = $0.075

TTS-1-HD Rate ($0.030 per 1000 characters)

10 characters = $0.030
999 characters = $0.030
1001 characters = $0.060
2500 characters = $0.090
4096 characters = $0.150

Thanks!

Hi and welcome to the Developer Forum!

Assuming it works the same as all the other API’s then it will be pro rata, i.e. 10 chars is 100th of 1000 so would be 100th of $0.015 or $0.030 so 0.00015 or 0.00030, when those amounts add up to 1 cent you will see it showing on your balance.

Hello Foxabilo!

Thank you for your reply!

So in other words the conversion rate is:

1 character = $0.000015 (tts-1)
1 character = $0.000030 (tts-1-hd)

Showed on account balance when the ammount reaches 1 cent.

If someone except me and Foxabilo could confirm that I would be grateful :slight_smile:

Thank you.

You could try a test that ran a 100 character speech generation and then check your account, it can take a few mins to update. Then try doing that generation 10 times over and see if you get a 1 cent bill, do it again and if you get a 3 cent bill then you know that’s how it works in reality.

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OpenAI bills by very small units. Individual $0.001 calls to embeddings models are accumulated by token counts.

Here’s a post of mine analyzing whisper, the other direction, also reaching that conclusion. Two days before the usage page was destroyed to prevent auditing.

The only thing that is still ambiguous about granularity is the per GB price of assistants’ retrieval documents.