Pricing comparison
Claude Sonnet 4.5 vs o3
Per-token pricing, full-workload cost ladders, and monthly volume projections. Numbers sourced directly from each provider's rate card.
Anthropic
Claude Sonnet 4.5
- Input
- $3.00 / 1M
- Output
- $15.00 / 1M
- Cached input
- -
- Context
- 200K
- Max output
- 64K
OpenAI
o3
- Input
- $2.00 / 1M
- Output
- $8.00 / 1M
- Cached input
- $0.500 / 1M
- Context
- 200K
- Max output
- 100K
Cost per request
Four common workload shapes, input tokens and a 1:2 output ratio (a standard chat/completion pattern). Long-context surcharges apply automatically where the provider charges them.
| Scenario | Tokens (in / out) | Claude Sonnet 4.5 | o3 | Winner |
|---|---|---|---|---|
| Short prompt | 100 / 200 | $0.0033 | $0.0018 | o3 |
| Typical request | 1,000 / 2,000 | $0.0330 | $0.0180 | o3 |
| Long document | 10,000 / 5,000 | $0.1050 | $0.0600 | o3 |
| Large prompt | 100,000 / 10,000 | $0.4500 | $0.2800 | o3 |
Monthly bill at scale
Projected monthly cost at typical request volume, assuming the "typical request" shape above (1k in, 2k out).
| Traffic | Req / month | Claude Sonnet 4.5 | o3 | Delta |
|---|---|---|---|---|
| Small SaaS | 1,000 | $33.00 | $18.00 | o3 -$15.00 |
| Growing product | 10,000 | $330.00 | $180.00 | o3 -$150.00 |
| Heavy usage | 100,000 | $3,300 | $1,800 | o3 -$1,500 |
Which should you use?
For the typical chat-shape request (~1k input, 2k output), o3 comes out 83% cheaper. If you're picking one as the default, that's usually the right choice on cost alone.
o3 wins on both sides of the bill - cheaper input and cheaper output. If the quality gap is in your favour, there's no cost argument for the other side.
Live cost calculator
Type in any token counts - both prices update instantly. Uses base input/output rates (no cache discount, no long-context tier).
Claude Sonnet 4.5
$0.0105
per request
o3
$0.0060
per request
Try both in the estimator →
Drop your actual prompt in, tokens are counted with the provider's own tokenizer, and the dollar number matches what lands on your invoice.
Frequently asked
- Which is cheaper, Claude Sonnet 4.5 or o3?
- On a typical 1,000-input / 2,000-output request, o3 costs ~$0.0180 vs ~$0.0330 on Claude Sonnet 4.5. Input or output rates can flip the answer for very lopsided workloads - see the cost ladder above.
- What's the difference in per-token pricing?
- Claude Sonnet 4.5 charges $3.00 per 1M input tokens and $15.00 per 1M output tokens. o3 charges $2.00 / $8.00 per 1M.
- Which has the bigger context window?
- Both hold 200K of input.
- Is there a cached-input discount on either?
- Claude Sonnet 4.5 does not publish a cached-input rate. o3 caches at $0.500 per 1M (75% off). Workloads with repeated static prefixes see the biggest savings.
- How fresh is this comparison?
- Claude Sonnet 4.5 was re-verified on 2026-04-06 and o3 on 2026-04-06 against each provider's published rate card. Calcis re-checks every row on a rolling schedule and re-deploys when a provider changes pricing.
Claude Sonnet 4.5 verified 2026-04-06 · o3 verified 2026-04-06. Rate cards at Anthropic and OpenAI.