Free API Pricing Calculator

Estimate your OpenAI API costs before you build. Calculate token usage for GPT-4, GPT-4o, GPT-3.5-Turbo, and more. Perfect for developers budgeting AI features and SaaS products.

OpenAI Token Cost Estimator

$0.00
Estimated Monthly Cost
Input Cost per Month$0
Output Cost per Month$0
Cost per 1K Requests$0
Total Monthly Tokens0

How to Use

Select your AI model, enter the average input tokens (your prompt) and output tokens (the response) per request, and your estimated monthly API call volume. The calculator shows total monthly cost broken down by input and output.

Token counts vary by language. As a rule of thumb, 1 token is roughly 0.75 words in English, so a 2,000-token prompt is about 1,500 words.

How Costs Are Calculated

Monthly Cost = ((Input Tokens × Input Price) + (Output Tokens × Output Price)) × Monthly Calls / 1,000,000

Frequently Asked Questions

A token is the basic unit of text that AI models process. One token is roughly 0.75 words or 4 characters in English. Different languages have different token-to-word ratios.
Use shorter, focused prompts (fewer input tokens). Set max_tokens limits to cap output length. Use GPT-3.5-Turbo or GPT-4o-mini for simpler tasks. Cache common responses. Batch requests where possible.
Yes, you pay for tokens sent in the request even if the API call fails or errors out. Tokens are counted as soon as they're processed by the model. However, if your request is rejected by the content filter or rate limiter before processing, you won't be charged.