AI Subscription vs API Calculator
Is ChatGPT Plus, Claude Pro or Google AI Pro worth it for you, or would paying per message through the API cost less?
Daily help with writing and questions: 5 chats a day, 6 messages each.
Picking a plan picks its nearest API model. Change it to compare any model.
Enter the price shown for your country on chatgpt.com/pricing. Prices there differ by country, so we don't fill one in.
New conversations you start.
Questions you send in each chat.
Average length of what you type or paste.
Average length of the AI's answer.
Hidden reasoning before the answer. Billed as output on the API.
Instructions or memory sent with every message.
Use 22 for weekdays only.
Each using AI like this. Team plans have a seat minimum.
Prices are in US dollars. Leave empty to use a rough rate.
Every plan at your usage
Each plan's price against the same usage on its nearest API model. Tap a plan to pick it.
Every API model at your usage
Cheapest first. The dashed line is your plan's price. Tap a model to pick it.
Beyond the price
Things that can matter more than a few dollars a month.
- Usage limits. Plans cap how much you can use the best models in a few hours or a week; heavy users hit them. The API has no such cap, only your budget and rate limits.
- Features in the apps. Plans include phone and desktop apps, voice chat, image making, deep research, agents, memory, projects and file uploads. On the API you get the model alone and pay for each of these separately, or build them.
- Privacy. API and business plans usually don't use your chats to train models by default. Personal plans may, unless you turn it off in settings. Check each provider's policy.
- Setting it up. The API needs an account, an API key and a chat app that accepts your key. A plan works the moment you sign in.
- Predictable bills. A plan is the same every month. The API costs more in a busy month, so set a spending limit.
- Choice of models. With the API you can switch between providers and use cheaper models for easy tasks. A plan ties you to one company's models.
How your subscription vs API answer is worked out
Your usage in tokens × the API price, set against the plan's monthly fee.
- 1
Messages a month
5 chats × 6 msgs× 30 days= 900 messages
- 2
Tokens, with history
In: 1.3M(1.23M resent chat)Out: 420.3K
- 3
Your API bill
1.3M × $2/M+ 420.3K × $10/M= $6.81 a month
- 4
Plan vs API
Plan $20.00API $6.81Break-even ≈ 88 msgs/dayAPI saves $13.19
Read more: the formula, a worked example, plan prices and what else to weigh
A subscription charges a flat fee a month however much you use it, up to its usage limits. The API charges per token: a token is a chunk of text, about ¾ of an English word, and what you send (input) and what the model writes back (output) are priced separately. In a chat, each new message also sends the whole conversation so far, so long chats use far more input tokens than the words you type.
The formula
messages a month = chats a day × messages per chat × days
new input per chat = messages × your message + files + instructions
resent history per chat = (your message + reply) × messages × (messages − 1) ÷ 2 + files × (messages − 1) + instructions × (messages − 1)
output per chat = messages × (reply + thinking)
API cost = (new input + resent history × 0.1 if cached) × input price ÷ 1,000,000 + output × output price ÷ 1,000,000
plan cost = price × seats (yearly price ÷ 12 if paid yearly)
break-even chats a day = plan cost per person ÷ (API cost per chat × days)
break-even messages a day = break-even chats × messages per chat
Worked example
Regular use is 5 chats a day of 6 messages, about 60 words typed (80 tokens) and 350-word replies (467 tokens), for 30 days: 5 × 6 × 30 = 900 messages a month. In each chat you send 6 × 80 = 480 new tokens, and the history resent with later messages adds (80 + 467) × 6 × 5 ÷ 2 = 8,205 tokens. Output is 6 × 467 = 2,802 tokens. Over 150 chats that is 1,302,750 input and 420,300 output tokens.
On Claude Sonnet 5.5 ($2 input, $10 output per million) the API costs 1.30275 × $2 + 0.4203 × $10 = $2.6055 + $4.203 = $6.81 a month ($6.8085), about $0.0076 a message. Claude Pro at $20 works out at $0.022 a message, so the API saves $13.19 a month ($158.30 a year). The break-even point is $20 ÷ ($6.8085 ÷ 150 × 30) = $20 ÷ $1.3617 = 14.69 chats, or about 88 messages a day. Use more than that and the plan is cheaper.
The same usage on GPT-5.6 Terra ($2 / $12) costs 1.30275 × $2 + 0.4203 × $12 = $2.61 + $5.04 = $7.65 a month: compare that with the ChatGPT Plus price shown for your country.
Usage presets
| Preset | Chats a day | Messages each | Words in / out |
|---|---|---|---|
| Light | 2 | 4 | 40 / 250 |
| Regular | 5 | 6 | 60 / 350 |
| Heavy | 10 | 10 | 100 / 500 |
| Power user | 20 | 15 | 150 / 700 + 1 image |
Plan prices used
| Plan | Monthly | Yearly | Nearest API model |
|---|---|---|---|
| Claude Pro | $20 | $200 ($16.67/mo) | Claude Sonnet 5.5 |
| Claude Max 5× | $100 | — | Claude Opus 5.5 |
| Claude Team Standard per seat, 2–150 people | $25 | $240 ($20/mo) | Claude Sonnet 5.5 |
| Claude Team Premium per seat, 2–150 people | $125 | $1,200 ($100/mo) | Claude Opus 5.5 |
| Google AI Plus | $4.99 | — | Gemini 3.8 Flash |
| Google AI Pro | $19.99 | — | Gemini 3.1 Pro (preview) |
| Google AI Ultra 5× | $99.99 | — | Gemini 3.1 Pro (preview) |
| Google AI Ultra 20× | $199.99 | — | Gemini 3.1 Pro (preview) |
| ChatGPT Go | Your price | — | GPT-5.6 Luna |
| ChatGPT Plus | Your price | — | GPT-5.6 Terra |
| ChatGPT Pro | Your price | — | GPT-5.6 Sol |
| ChatGPT Business per seat, from 2 people | Your price | — | GPT-5.6 Terra |
US list prices in US dollars before tax, checked on 10 October 2026 on each provider's pricing page. Claude Pro's yearly price is $200, which the page shows as $17 a month. Google AI Ultra is listed as "starting at" $99.99 (5× Pro usage) or $199.99 (20× Pro usage), and Claude Max as "from" $100 (5× Pro usage); no yearly Google prices were listed. ChatGPT shows prices per country, so enter the one you see. Prices in other countries may be set locally and include tax. The "nearest API model" is our rough match for what each app uses; apps switch models often. Local amounts use a rough exchange rate (for example 1 USD ≈ 88 INR or 3.6725 AED) unless you enter your own. API prices checked on 9 October 2026.
Notes
- Chat history: apps and most API chat tools resend the conversation with each message. Turning this off shows the cost if every message were a fresh question.
- Thinking: models that reason before answering bill that reasoning as output on the API, even though you don't see it. Apps include it in the plan.
- Prompt caching: input the model has seen recently costs about a tenth of the normal price with all three API providers. Not every chat app uses it.
- Plans aren't unlimited: if the break-even point is far above your use, the API is cheaper; if your use is far above it, check the plan's limits too.
Common questions
Is Claude Pro worth it?
It depends on how much you use it. At regular use (5 chats a day, 6 messages each, 900 messages a month) the same messages on Claude Sonnet 5.5 through the API cost about $6.81 a month, less than the $20 plan. At heavy use (10 chats of 10 messages a day) the API costs about $42, so the plan wins. Plans also include apps, voice and other tools.
Is ChatGPT Plus worth it?
ChatGPT prices are shown per country on chatgpt.com/pricing, so pick ChatGPT Plus and type the price you see. The calculator compares it with the same messages on GPT-5.6 Terra through the API, which costs about $7.65 a month at regular use (900 messages). If your plan price is well above your API cost, paying per use is cheaper.
Why do long chats cost more on the API?
Each new message sends the whole conversation so far back to the model as input, so message 10 of a chat carries the 9 questions and answers before it. In the regular example, 1.23 million of the 1.3 million input tokens a month are resent chat history. Starting fresh chats more often, or prompt caching, cuts this a lot.
How many messages a day make a subscription worth it?
The calculator finds the break-even point: the number of messages a day at which the API would cost the same as the plan, keeping your chat length the same. For regular-length chats on Claude Sonnet 5.5 against the $20 Claude Pro plan it is about 88 messages a day. Below that the API is cheaper; above it the plan is.
Is a team plan cheaper than the API for a small team?
Team plans charge per seat. Claude Team Standard is $25 a seat a month, or $20 a month billed yearly, for 2 to 150 people, so a team of 3 pays $75 a month. Set the number of people in Advanced to compare that with the API bill for everyone together.
What do AI subscriptions include that the API does not?
Subscriptions come with ready-made apps for phone and desktop, voice chat, file uploads, image tools, research and agent features, memory and projects. The API gives you the raw model: you need your own app or chat tool, and you pay for every token. Plans have usage limits; the API has none beyond your budget and rate limits.
How can I use the AI API instead of a subscription?
Create an account on the provider's developer platform, add credit and make an API key. Then use a chat app that accepts your own key, or a simple script. Set a monthly spending limit so a long session can't surprise you, and start new chats often, since long chats resend their history with each message.
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