ChatGPT API Cost Calculator
Estimate the cost of building on OpenAI's API — from GPT-5.6 down to GPT-4o — for your exact usage.
Usage
$1.25/M in · $0.125/M cached in · $10.00/M out · 400K context
Estimated cost
$187.50/month
Per request
$0.00625
Per day
$6.25
Per year
$2,281.25
Compare across models
| Model | Provider | Per month |
|---|---|---|
| OpenAI | $7.50 | |
| OpenAI | $13.50 | |
| OpenAI | $24.00 | |
| OpenAI | $36.00 | |
| OpenAI | $37.50 | |
| OpenAI | $37.50 | |
| $46.50 | ||
| $78.75 | ||
| Anthropic | $105.00 | |
| OpenAI | $180.00 | |
| OpenAI | $180.00 | |
| $180.00 | ||
| OpenAI | $187.50 | |
| Anthropic | $210.00 | |
| OpenAI | $225.00 | |
| OpenAI | $240.00 | |
| $240.00 | ||
| Anthropic | $315.00 | |
| OpenAI | $420.00 | |
| Anthropic | $525.00 | |
| Anthropic | $525.00 | |
| Anthropic | $525.00 | |
| Anthropic | $1,050.00 |
How this is calculated
Providers bill input and output tokens separately, per million tokens (MTok). Cached input tokens — a repeated prompt prefix the provider recognizes — are billed at a discounted rate.
cost = (input_tokens − cached_tokens) × input_rate
+ cached_tokens × cached_rate
+ output_tokens × output_ratePricing is verified against provider pricing pages as of 2026-09-01. AI and cloud pricing changes frequently — confirm the current rate on the provider's own pricing page before budgeting.
Frequently asked questions
Is the ChatGPT API the same as OpenAI's API?
Yes — 'ChatGPT API' commonly refers to OpenAI's Chat Completions / Responses API, which powers ChatGPT and is billed per token, separately from the consumer ChatGPT Plus subscription.
Which GPT model should I use to keep costs down?
GPT-5.6 Luna and GPT-5-nano are the cheapest current tiers, suited to simple classification or extraction. Reserve GPT-5.6 Sol or GPT-5.1 for tasks that need stronger reasoning.
Does OpenAI offer a cheaper way to process large volumes?
Yes — the Batch API processes non-latency-sensitive requests asynchronously at roughly half the standard per-token price. This calculator estimates standard synchronous pricing.
How is this different from my ChatGPT Plus subscription cost?
ChatGPT Plus is a flat monthly consumer subscription with usage limits. The API is billed per token with no subscription fee, which is typically far cheaper at low volume and more predictable at scale.