Usage Limits

Last updated: October 13, 2026

Ignigrade is free to use. Because every chat message costs us money to process, chat usage is limited by various usage quotas.

What's free

The calculator — building scenarios, running simulations, and viewing results — is free, with no limits.
The AI chat is free to use within the quotas below, even without signing in. Without signing in you get a smaller guest quota that refills daily; signing in gives you more, and your guest conversations carry over to your account.

Chat quotas

The chat is subject to availability, based on various usage quotas. When a quota is used up, chat messages are refused with a message saying so. The calculator keeps working.

Why some messages use more of your quota

Behind the scenes, every message is processed by an AI model, and how much it uses depends on the amount of text involved:

What the AI reads (input): your message, plus the instructions and scenario data it needs to answer, plus the earlier messages in the conversation, which are sent again every time.
What the AI writes (output): the reply, plus any behind-the-scenes reasoning or simulations it runs to get there.

Long conversations use more per message, because the whole conversation is sent again with each new message. If you switch to an unrelated topic, starting a new chat makes your quota last longer.
Your last message can go past the quota. As long as any quota is left, your next message is answered in full, even if it uses more than what remained.
Failed replies don't count. If the AI returns an error instead of a reply, none of your quota is used.

Changes

The free chat is provided on a best-effort basis. We may change the quotas, pause the chat, or end free access at any time.

Questions

Email info@ignigrade.com.