OpenAI API Cost Calculator
Estimate OpenAI GPT-4o, GPT-4o mini and o-series API costs.
Results update automatically as you type.
- Input cost
- $0.00250
- Output cost
- $0.00500
- Per request
- $0.00750
- Per day
- $7.50
- Per month
- $225.00
Estimate the cost of the OpenAI API for GPT-4o, GPT-4o mini, and the o-series reasoning models. Enter your token counts and traffic to see per-request and monthly cost, including prompt caching and batch pricing where available.
How this is calculated
This calculator uses the api cost formulas described in our methodology. All figures are estimates for planning; verify current pricing with each provider before relying on them.
Worked example (defaults)
With the default inputs above, here is the result:
- Input cost
- $0.00250
- Output cost
- $0.00500
- Per request
- $0.00750
- Per day
- $7.50
- Per month
- $225.00
Frequently asked questions
Which OpenAI models are cheapest?+
GPT-4o mini is dramatically cheaper than GPT-4o for most tasks, while o-series reasoning models cost more due to higher output pricing and reasoning tokens.
Does prompt caching lower OpenAI cost?+
Yes. Cached input tokens are billed at a reduced rate, which helps a lot when you reuse a large system prompt or context across requests.