LLM pricing · Compare

Claude Sonnet 4.5 vs Claude Sonnet 5.5 pricing (November 2026)

In short: Claude Sonnet 5.5 is 1.5× cheaper than Claude Sonnet 4.5 per chat message: $0.0070 vs $0.0105 for a typical chat turn (1,500 tokens in, 400 out). On a $9.99 plan, a user can send about 1,213 messages a month on Claude Sonnet 5.5 before they cost more than they pay, versus 808 on Claude Sonnet 4.5.

Price per million tokens

Claude Sonnet 4.5Claude Sonnet 5.5
ProviderAnthropicAnthropic
Input$3$2
Cached input$0.3$0.1
Output$15$10
Long promptssame ratesame rate

Cost per message and per user

Claude Sonnet 4.5Claude Sonnet 5.5
Per message$0.0105$0.0070
Per message, prompt 2/3 cached$0.0078$0.0051
Light user (30 msgs/mo)$0.315$0.210
Typical user (300 msgs/mo)$3.15$2.10
Heavy user (3,000 msgs/mo)$31.50$21.00
Break-even on $9.99808 msgs/mo1,213 msgs/mo

Red: the user costs more in AI than the $8.49 you keep from a $9.99 plan after a 15% store fee.

Which to use

Price is only half of it: pick the cheapest model that gives answers your users accept. Many apps route most traffic to the cheaper model and send only hard requests, or only paying users, to the stronger one. Whatever the mix, the number that decides your margin is cost per user, because a few heavy users usually drive most of the bill.

Try your own numbers

Cost per message
$0.0070
AI cost per user / month
$2.10
Margin per user / month
$6.39
Break-even messages / month
1,213

List prices, standard tier, prompts under the long-context threshold. Averages hide your heaviest users: FiscaLLM shows this per real user.

Track the real cost of each user

FiscaLLM prices every Anthropic call with these rates, per user, and sets it next to what that user paid through RevenueCat, Stripe or a CSV. You see which users and which model lose you money. Free and open source. See the demo.

Questions

Is Claude Sonnet 4.5 or Claude Sonnet 5.5 cheaper?

Claude Sonnet 5.5 is 1.5× cheaper than Claude Sonnet 4.5 per chat message: $0.0070 vs $0.0105 for a 1,500-token prompt and a 400-token reply, at list prices.

How many messages can a $9.99 subscriber send on each?

About 808 a month on Claude Sonnet 4.5 and 1,213 on Claude Sonnet 5.5, before AI cost uses up what you keep after a 15% store fee.

Can I use both?

Yes. A common pattern is the cheaper model for most traffic and the stronger one for hard requests or paying users. Track cost per user to see whether the mix pays off.

List prices, standard tier. Batch, priority and regional pricing differ; check each provider for the latest.