AI subscription vs API calculator
← All tools· Inference cost calculator (product-scale estimates)
Paying $20/mo for ChatGPT Plus or Claude Pro? This calculator estimates what the same usage would cost on the vendor API — and shows the break-even point where a flat subscription stops making sense.
Your subscription
Your usage (all editable)
Each user + assistant turn counts as one message.
System prompt + history + context. ~4 chars ≈ 1 token.
messages/day · messages/mo · input tokens · output tokens
vs equivalent API
API equivalent
/mo
Subscription
/mo
Break-even:— messages/day where API cost equals the subscription price (holding token sizes and active days fixed).
Every subscription at your usage
API-equivalent monthly cost using each plan's mapped model. Click a row to select it. Prices verified July 2026; API rates July 2026.
| Plan | API model | Sub $/mo | API $/mo | Verdict |
|---|---|---|---|---|
Caveats
- Subscriptions bundle chat UI, file uploads, image generation, voice, and rate limits — not just raw tokens. This tool compares token-equivalent API spend only.
- API prices are standard (non-batch) tier. Batch, cached-input, and enterprise discounts are not modeled.
- Subscription usage caps and model routing (e.g. which model answers in the app) differ from a direct API call. Mapped models are rough equivalents, not exact matches.
- All figures are estimates for planning — not billing quotes.
How it works
Pick a consumer AI subscription and describe how you use it: conversations per day, messages per thread, average token sizes, and how many days per month you actually chat. The calculator multiplies that into monthly message and token counts, then prices those tokens at the mapped API model's published per-million rates (July 2026).
The break-even line shows how many messages per day would make API spend equal the flat subscription — useful if you're deciding whether to stay on Plus/Pro or wire up your own API key. Building a product with thousands of users? Use theinference cost calculator instead.
Privacy: everything runs in your browser. No usage data is sent to a server. Shareable URLs encode your inputs in the query string only.