API cost calculator for language models
Estimate a language model's monthly cost for your use case before you integrate an API.
Calculate API usage
Many AI tools use subscriptions. Others charge by usage or provide prices only on request. The calculator below estimates API costs from your inputs for selected language models.
How to read the inputs
A request is one call to a model. Input tokens are the text you send, and output tokens are its answer. Use averages from a typical prompt and response.
What is the calculator for?
Use it, for example, to plan budgets for support bots, document analysis, coding assistants, or similar. It compares published unit prices, not a model's quality or suitability.
How the cost estimate works
Key answers in plain language, to help you get a realistic first budget figure.
Where do the prices come from?
They come from OpenRouter's public price list. You therefore see what a model costs through OpenRouter. That can differ from the price charged directly by the model maker. The source and data timestamp appear at the bottom of the calculator.
How fresh is the data?
The calculator tells you when it loaded the model data. If an update fails, it uses the last confirmed data and says so clearly.
How is the monthly price calculated?
Simply: your monthly requests × the average length of a question and answer × the model price. More or longer conversations raise the amount. Extra features are included only when you enable them and a price is available.
What do the extra inputs mean?
Input is your text and output is the model's reply. You can optionally include reused text from a cache, a model's internal reasoning work, images, audio or web searches. Use those fields only when they fit your project.
What happens with reused text?
Some providers charge less when text can be reused from a cache. If a published special price exists, the calculator uses it. Otherwise it cautiously uses the normal input price rather than assuming a discount.
Does the calculator include special prices?
Yes, but only when OpenRouter publishes them for that exact access route, for example based on text length or time. Unlisted discounts and special terms are never guessed.
Why does it check technical limits?
So a low estimate is not shown for something that cannot work. The calculator checks whether the question and reply fit the model, and whether extras such as images, audio or web search are supported.
What is not included in the price?
The result is a budgeting aid, not an invoice. Taxes, your individual contract, account limits, minimum commitments and unpublished discounts are not included. If something has no price, the calculator does not show a deceptively exact amount.
Is the cheapest model automatically the best?
No. The calculator compares costs, not quality. Also check whether a model really suits your language, tasks, preferred reply length and features.
Compare models directly
Compare prices, limits and sources for common models side by side.