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Gemini 3.1 Pro API Cost Calculator

Price Gemini 3.1 Pro at $2 in and $12 out per million tokens, with its higher rates above 200,000 tokens and the hourly cost of its context cache.

Updated · By Niraj Kumar · 6 sources

Each request

Count text inCount text in
tokens

System prompt, conversation history, documents and tool definitions are all resent on every call.

tokens

The visible answer.

Count tokens from a prompt or JSON payloadShow

Plain text, OpenAI Chat or Responses JSON, or Anthropic Messages JSON. A final assistant message or a response body counts as output. Counted in your browser; nothing is uploaded.

Loading the tokenizer…

Counts use OpenAI's o200k tokenizer, so they are exact for GPT-6 and GPT-5 models, plus a few tokens of message framing. Other providers' tokenizers count the same text differently and do not publish a conversion factor; Anthropic says Claude models from 4.7 on produce about 30% more tokens than earlier Claude models. For an exact count on another model, paste one of its API responses: the usage it reports is shown above.

tokens

Thinking tokens are billed as output. Leave at 0 for models or settings that do not reason.

Volume

PricePrice

30,000 requests over 30 days.

Discounts

%
0%100%

The share of input that repeats exactly at the start of every request, such as a fixed system prompt. The prompt caching calculator prices cache writes and expiry in detail.

Batch APIBatch API
Monthly cost$360.00$0.012 a request on Gemini 3.1 Pro
Per 1,000 requests
$12.00
Input
$180.00
Output
$180.00
Price rank
19th cheapest of 24
Cheapest listed model
Claude Haiku 5.5
$16.50 a month, $343.50 less
Output50%
  • Input50%
  • Output50%
Every model on this workload, per month3,000 tokens in, 500 out, 1,000 a day. Hover or focus a row for rates.
  1. 1Claude Haiku 5.5Anthropic$16.50
  2. 2GPT-6 LunaOpenAI$16.50
  3. 3Qwen3.8 FlashAlibaba$20.55
  4. 4GPT-5.6 LunaOpenAI$36.00
  5. 5DeepSeek V4.1 FlashDeepSeek$45.00
  6. 6Qwen3.7 PlusAlibaba$60.00
  7. 7Gemini 3.5 Flash-LiteGoogle$64.50
  8. 8Gemini 3.8 FlashGoogle$123.75
  9. 9Grok 4.3xAI$150.00
  10. 10Claude Haiku 4.5Anthropic$165.00
  11. 11DeepSeek V4 ProDeepSeek$178.20
  12. 12Grok 4.7xAI$270.00
  13. 13Qwen3.8 MaxAlibaba$270.00
  14. 14Claude Sonnet 5.5Anthropic$330.00
  15. 15Claude Sonnet 5Anthropic$330.00
  16. 16GPT-6.1 SolOpenAI$330.00
  17. 17GPT-6 SolOpenAI$330.00
  18. 18GPT-5.6 TerraOpenAI$360.00
  19. 19Gemini 3.1 ProGoogle$360.00
  20. 20Claude Opus 5.5Anthropic$660.00
  21. 21GPT-5.6 SolOpenAI$660.00
  22. 22Claude Opus 5Anthropic$825.00
  23. 23Claude Fable 5.1Anthropic$1,650
  24. 24GPT-6 AstraOpenAI$1,650

How the Gemini 3.1 Pro API Cost Calculator works

As of October 13, 2026, Gemini 3.1 Pro costs $2 per million input tokens and $12 per million output tokens, with cache hits at $0.20. A request costs its input tokens × the input rate ÷ 1,000,000 plus its output tokens × the output rate ÷ 1,000,000; multiply by requests for the monthly bill.

cost = (fresh input × input rate + cached input × cache rate + (output + reasoning) × output rate) ÷ 1,000,000

This page uses the same method as the LLM API Cost Calculator, which explains each term and assumption in full.

Worked example

A chat feature on Gemini 3.1 Pro sending 3,000 input tokens and getting 500 back, 1,000 times a day.

  1. 1Input: 3,000 × $2 ÷ 1,000,000 = $0.006
  2. 2Output: 500 × $12 ÷ 1,000,000 = $0.006
  3. 3Per request: $0.012
  4. 4Per month: $0.012 × 1,000 × 30 = $360.00

$360.00 a month. Caching a fixed system prompt that makes up 80% of the input would bring it to about $230.40, and the batch API would halve either figure.

Frequently asked questions

How much does Gemini 3.1 Pro cost per million tokens?

$2 per million input tokens and $12 per million output tokens at Google's standard rate. Cache hits are $0.20, and keeping an explicit cache costs $4.50 per million tokens an hour. The batch API takes 50% off. Prompts over 200,000 tokens are billed at $4 input and $18 output for the whole request.

How does Gemini 3.1 Pro's pricing change for long prompts?

Prompts over 200,000 tokens are billed at $4 input, $0.40 cached and $18 output per million tokens instead of $2, $0.20 and $12. Its explicit context cache also costs $4.50 per million tokens for every hour it is kept, which only pays off above about 2.5 hits an hour. Google still labels the model a preview.

How big a request can Gemini 3.1 Pro take?

Up to 1.05 million tokens of context, input and output together, and up to 65,536 output tokens per response. That is roughly 790,000 words of English. The calculator warns when a request will not fit.

Sources

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