API vs Subscription Break-even Calculator
Short answer: a flat monthly fee and a metered API bill cross over at a request rate you can calculate. At 10,000-token requests with 15% output, $20 a month is worth 2,500,000 tokens on Claude Opus 5 and 57,142,857 on GPT-5.6 Luna — a 22.9x spread, or 8.3 requests a day against 190.5. Enter your own plan price and volume below: we publish no subscription prices, so every figure here is driven by the number you type.
Find your break-even request rate
Four inputs: what the flat plan costs you, how big a request is, how much of it is output, and how many you run a day. Everything else is computed from verified per-1M rates.
| Model | Blended rate / 1M | Cost per request | Monthly at this volume | Against your plan | Break-even requests / day |
|---|
$20 a month, in tokens
At 10,000-token requests with 15% output — a realistic RAG or support shape — this is how much usage a $20 monthly plan is equivalent to on each model. The plan price is an example you replace with your own.
| Model | Blended rate / 1M | Tokens per month | Requests per day |
|---|---|---|---|
Claude Opus 5 Anthropic · flagship | $8.00 | 2,500,000 | 8.3 |
GPT-5.6 Sol OpenAI · flagship (promo) | $6.40 | 3,125,000 | 10.4 |
GPT-5.6 Terra OpenAI · mid | $3.50 | 5,714,286 | 19.0 |
Claude Sonnet 5 Anthropic · mid | $3.20 | 6,250,000 | 20.8 |
Claude Haiku 4.5 Anthropic · budget | $1.60 | 12,500,000 | 41.7 |
Gemini 3.6 Flash Google · mid (promo rate) | $1.20 | 16,666,667 | 55.6 |
Gemini 3.5 Flash-Lite Google · budget | $0.63 | 31,746,032 | 105.8 |
GPT-5.6 LunaMost headroom OpenAI · budget | $0.35 | 57,142,857 | 190.5 |
Blended rate is the input and output rates weighted 85/15 — the mix used throughout this page. Tokens per month is $20 divided by the blended rate; requests per day divides that by 30 and by 10,000 tokens. The 22.9x spread between Claude Opus 5 and GPT-5.6 Luna is the same spread you see on any per-token comparison — model choice moves the answer far more than the budget does. Caching, batch, tool use and taxes excluded.
Bigger requests, fewer of them
Break-even is a function of request size as much as of price, because a flat fee buys a fixed number of tokens however you slice them.
The same $20 a month, expressed in requests per day at three request sizes:
| Tokens per request | GPT-5.6 Sol | Claude Sonnet 5 | GPT-5.6 Luna |
|---|---|---|---|
| 10,000 | 10.4 / day | 20.8 / day | 190.5 / day |
| 25,000 | 4.2 / day | 8.3 / day | 76.2 / day |
| 50,000 | 2.1 / day | 4.2 / day | 38.1 / day |
Doubling request size halves the request count you can afford — on both sides of the comparison. A chat interface that quietly re-sends a 50,000-token transcript on every turn is spending the equivalent of $0.3200 a turn on GPT-5.6 Sol at this mix, so a $20 plan covers about 62 such turns. In the API you pay that openly; in a flat plan it is absorbed until you hit a usage cap.
That is the structural difference worth pricing: a subscription caps your downside and hides your unit cost; the API exposes the unit cost and leaves the downside open. The calculator above tells you where the two meet for your own numbers.
When a flat plan wins, and when it does not
Both answers are stable across the models tracked here — they follow from the shape of the pricing, not from any particular rate.
The subscription wins when volume is high and steady. Past the break-even rate, metered tokens cost more than the fee every single month, and the flat price removes the variance. It also wins when each request is expensive because it carries a long context: chat interfaces re-send history as part of the product, and that traffic is not on your meter.
Pay-per-token wins when volume is low or spiky. A month with 200 requests costs $12.80 on GPT-5.6 Sol at the shape above, not $20. Nothing is billed when nothing is sent, which no subscription can match.
Pay-per-token also wins when you can choose the model. The same $20 of usage is 2,500,000 tokens on Claude Opus 5 and 57,142,857 on GPT-5.6 Luna. Routing easy traffic to a cheap tier — draft on Luna, final pass on a flagship — is the single biggest move available on the metered side, and it has no equivalent in a single-model plan. See How to Reduce LLM API Costs.
Certainty has a price. A fixed fee converts an unknown bill into a known one. If the alternative is an unbounded API bill nobody is watching, the subscription may be worth the premium even above break-even.
What this comparison does not include
We publish no subscription prices, and this page prices one thing only: the token meter.
API vs subscription questions
Is the API cheaper than a ChatGPT or Claude subscription?
It depends on your volume, your model and your request size. Enter your plan price and usage above: at 10,000-token requests with 15% output, a $20 plan is worth 8.3 requests a day on Claude Opus 5 and 190.5 requests a day on GPT-5.6 Luna. Above your break-even rate the flat fee wins; below it, metered tokens do.
How many tokens does $20 a month buy?
At 10,000-token requests with 15% output, $20 buys 2,500,000 tokens on Claude Opus 5, 3,125,000 on GPT-5.6 Sol, 6,250,000 on Claude Sonnet 5 and 57,142,857 on GPT-5.6 Luna — a 22.9x difference. Model choice moves the answer far more than the budget does.
What is a break-even request rate?
It is the number of requests per day at which metered API spend equals your monthly subscription: the plan price divided by the cost of one request, divided by 30. Cross it and the subscription is cheaper; stay under it and pay-per-token is. Because cost is linear, ten times the budget buys ten times the volume.
Do subscriptions include more than tokens?
Yes, and none of it is priced here. We publish no subscription prices and compare no bundled features, rate limits, model access, retention or support tiers. This calculator prices the token meter only, using your own plan price as the input.
When does pay-per-token lose?
When volume is high and steady, when each request carries a long context that a chat interface would re-send for free, when you have no engineering time to optimise prompts, and when the flat plan also removes a rate limit you would otherwise hit. Flat pricing converts an unknown bill into a fixed one — that certainty has value the arithmetic does not show.
Does the answer change with request size?
Yes, and linearly. A $20 budget covers 10.4 requests a day on GPT-5.6 Sol at 10,000 tokens per request, 4.2 at 25,000 tokens and 2.1 at 50,000 tokens. Doubling request size halves the number of requests you can afford, whichever side of the comparison you are on.
Where these numbers come from.
Token rates are published per-1M input and output prices, re-verified weekly against official provider documentation: OpenAI 2026-08-23, Anthropic and Google 2026-08-09 to 2026-08-16. The blended rate is those two prices weighted by your input/output mix; cost per request multiplies it by your request size; the monthly figure multiplies by 30 days. Break-even requests per day is your plan price divided by cost per request, divided by 30. The plan price, request size, output share and daily volume are your inputs — we publish no subscription prices, and the $20 used in the worked examples is illustrative. Caching, batch, tool use, taxes and every non-token element of a subscription are excluded throughout.
Official sources: OpenAI model docs, Anthropic pricing, Google Gemini API pricing.