Subscription vs API: which costs less?
A flat-rate plan like Claude Max or ChatGPT Pro pays off only if you would otherwise spend more on API tokens. Enter how you use AI and compare the two, using official list prices.
Subscription vs API cost calculator
At this usage the API is cheaper by $78.88 a month. You would need more than 3,125 messages a month for Claude Max 5x to pay off. Subscriptions cap usage in ways providers don’t publish in tokens; the API has no cap but bills every token. See all Claude plans.
How many API messages each plan’s price buys
Break-even for a message of 4,000 input tokens (prompt plus conversation so far) and 800 output tokens, on the plan’s flagship model. Use the plan if you send more than this each month.
| Plan | Price | API model | Cost per message | Break-even / month | ≈ per day |
|---|---|---|---|---|---|
| ChatGPT Plus | $20.00 | GPT-6.1 Sol | $0.016 | 1,250 | 42 |
| ChatGPT Pro (5x) | $100.00 | GPT-6.1 Sol | $0.016 | 6,250 | 208 |
| ChatGPT Pro (20x) | $200.00 | GPT-6.1 Sol | $0.016 | 12,500 | 417 |
| ChatGPT Pro ($500) | $500.00 | GPT-6.1 Sol | $0.016 | 31,250 | 1,042 |
| Claude Pro | $20.00 | Claude Opus 5.5 | $0.032 | 625 | 21 |
| Claude Max 5x | $100.00 | Claude Opus 5.5 | $0.032 | 3,125 | 104 |
| Claude Max 20x | $200.00 | Claude Opus 5.5 | $0.032 | 6,250 | 208 |
| Google AI Pro | $19.99 | Gemini 3.8 Flash | $0.006 | 3,331 | 111 |
| Google AI Ultra | $99.99 | Gemini 3.8 Flash | $0.006 | 16,665 | 556 |
| Google AI Ultra (20x) | $199.99 | Gemini 3.8 Flash | $0.006 | 33,331 | 1,111 |
| Claude Code via Claude Pro | $20.00 | Claude Opus 5.5 | $0.032 | 625 | 21 |
| Claude Code via Claude Max 5x | $100.00 | Claude Opus 5.5 | $0.032 | 3,125 | 104 |
| Claude Code via Claude Max 20x | $200.00 | Claude Opus 5.5 | $0.032 | 6,250 | 208 |
| OpenAI Codex via ChatGPT Plus | $20.00 | GPT-6.1 Sol | $0.016 | 1,250 | 42 |
| OpenAI Codex via ChatGPT Pro | from $100.00 | GPT-6.1 Sol | $0.016 | 6,250 | 208 |
When the API wins, and when the plan does
- Light or uneven use favors the API. You pay only for the tokens you send, and a quiet month costs almost nothing.
- Heavy daily use favors the plan, as long as you stay under its usage limits. Coding agents that resend large files are where subscriptions save the most.
- Long conversations cost more per message on the API, because every reply resends the history as input. Prompt caching cuts that cost; see the pricing guide.
- Apps and automation need the API regardless of price: subscriptions are for people using the provider’s own apps.
Count the tokens in a real conversation with the token counter, or compare plans directly on the subscriptions and coding tools pages.
Frequently asked questions
- Is Claude Max worth it compared with the API?
- Claude Max 5x costs $100.00 a month. The same money buys about 3,125 Claude Opus 5.5 API messages of 4,000 input and 800 output tokens — roughly 104 a day. Claude Max 20x, at $200.00, breaks even at about 6,250 messages. If you send more than that and stay within Max’s usage limits, the subscription is cheaper; below it, the API is.
- How many messages does Claude Pro’s price buy on the API?
- About 625 Claude Opus 5.5 messages a month for $20.00, assuming 4,000 input and 800 output tokens each. Long conversations send the whole history as input, so later messages cost more.
- Is ChatGPT Plus cheaper than the OpenAI API?
- $20.00 a month buys about 1,250 GPT-6.1 Sol API messages of the same size. Light users usually spend less on the API; daily heavy users usually save with Plus, within its usage limits.
- How many tokens do Claude Pro or Max include?
- Anthropic and OpenAI describe subscription limits as relative usage (for example 5x or 20x Pro) that varies with message length and model, not as a fixed token allowance. That is why this calculator compares cost per message instead of a token quota.