OpenAI API Pricing Structure Guide
OpenAI charges for API usage on a pay-as-you-go model per 1,000,000 tokens processed. Input tokens (the text and context sent in your prompt) and output tokens (the response generated by the model) carry different rate multipliers.
Frequently Asked Questions
How does the OpenAI API Cost Calculator work?
The calculator applies official OpenAI API rates per 1,000,000 input and output tokens for models like GPT-4o, GPT-4o-mini, o1, and embeddings to estimate call and monthly costs.
What is OpenAI Batch API pricing?
OpenAI Batch API offers a 50% discount on input and output tokens for asynchronous workloads completed within 24 hours.
How much cheaper is GPT-4o-mini compared to GPT-4o?
GPT-4o-mini costs $0.15 per million input tokens and $0.60 per million output tokens—over 95% cheaper than standard GPT-4o ($2.50 / $10.00).
What are reasoning tokens in OpenAI o1 and o3 models?
Reasoning models like OpenAI o1 generate internal thinking tokens before responding. These internal reasoning tokens are billed as output tokens at standard rates.
Is my text or API key required to use this calculator?
No. You do not need an API key or login. The calculator runs 100% locally in your web browser.
What are fine-tuning API costs?
Fine-tuned models incur training cost per million tokens (e.g. $25/M tokens for GPT-4o fine-tuning) plus slightly higher per-call inference rates.
How does vision image processing token pricing work?
OpenAI Vision converts images into 512x512 tile tokens (approx 170 to 765 tokens per image depending on detail mode).
Is this OpenAI cost calculator free to use?
Yes. ToolzTotal provides 100% free AI pricing and developer tools with no signups, no subscriptions, and zero limits.
Sources & References
Related Calculators & Tools
Browse AI Tools →Estimate token counts, context window consumption, and cost across GPT-5, GPT-4o, Claude 3.5, and Gemini 2.0.
Calculate monthly API bills across GPT-4o, GPT-4o-mini, o1, o3-mini, and text-embedding models.
Calculate Anthropic Claude 3.5 Sonnet, Claude 3 Opus, and Haiku API costs with prompt caching discounts.
Calculate Google Gemini 1.5 Pro, Flash, and Gemini 2.0 API costs based on token throughput.