AI Chatbot Cost Calculator
Turn daily message volume into a monthly chatbot API bill.
A support bot or assistant that feels cheap per reply adds up over a month of traffic. This chatbot running cost estimator projects the bill from three things: how many messages a day it handles, the average tokens in and out of each turn, and the model behind it. Because a chatbot resends the system prompt and conversation history on every turn, input tokens dominate — this tool makes that visible so you can see conversational ai pricing before you scale, and decide whether trimming history or dropping to a cheaper model is worth it.
Your chatbot
Monthly cost
$16.20
$0.000270 per message on GPT-4o mini
- Per message
- $0.000270
- Per day
- $0.5400
- Per year
- $197.10
- Tokens / day
- 2,100,000
Prices updated January 2026. The biggest lever is input tokens: resending long conversation history every turn inflates the prompt fast. Trim history or summarize it to cut the bill. Verify rates with the provider.
How it works
- 1
Choose the model
Pick the model your bot runs on. Input and output rates appear underneath so you can compare a premium model against a cheaper one for the same traffic.
- 2
Set the traffic
Enter messages per day and the average input and output tokens per message. Remember input includes the system prompt plus any history you resend each turn, which is usually the largest share.
- 3
Read the monthly bill
The headline is the monthly cost; the stats break it into per-message, per-day and per-year figures plus tokens a day, so you can size infrastructure and budget together.
Instant & 100% private — nothing is uploaded
Every calculation runs locally in your browser. The prompts, token counts and numbers you enter stay on your own device and are never sent to a server — nothing is stored, logged or shared.
Frequently asked questions
- Why are input tokens so much of the chatbot api cost?
- A chatbot has no memory between calls, so to stay coherent it resends the system prompt and the prior conversation on every turn. That history grows with the chat, so a long conversation can send thousands of input tokens per reply even when each user message is short.
- How do I bring the cost down?
- Trim or summarize conversation history instead of resending it verbatim, cap the reply length, cache the system prompt if the provider supports it, and use a smaller model for routine turns. Each lever attacks the token count directly.
- Does this include hosting or vector search?
- No. This is the language-model API cost only. Retrieval, a vector database, hosting and moderation calls are separate line items — add them on top for the full running cost.
- How do I estimate tokens per message?
- Look at a few real transcripts and count the system prompt, the resent history and a typical reply, or use a token counter on sample turns. Averaging several real conversations gives a far better figure than a guess.
Important
For planning and estimates only. Prices come from a published rate table dated on the page; providers change pricing without notice, and token counts here are approximations. Confirm against the provider’s own pricing before you budget or commit.
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