Home / GPT-6 vs Claude Cost
Where does Claude Opus 5.5 land against the three GPT-6 tiers? On published rates it sits between Sol and Astra — 2× Sol on input and output. But cross-vendor math has a catch: caching works differently at Anthropic. Read the caveat before the numbers.
✓ Last verified: October 10, 2026 · Manually verifiedRead this before comparing across vendors. Anthropic's published "cached input" price ($0.20/1M) is the cache-hit rate — but cache writes cost 1.25–2× the base input price and are not modeled in our calculator. So Claude estimates below are a lower bound for workloads with heavy cache churn. Processing availability is model-specific. Claude models are currently modeled only at Standard, with regional processing off and no cache writes. Unsupported combinations are shown as unavailable; OpenAI's Fast/Flex/Batch multipliers are not applied to Claude. Full policy: methodology page.
Pick a model, set your workload, and compare the listed models side by side. Prices come from the same data layer as every calculator on this site — never hard-coded per page.
Current Sol: GPT-6.1 Sol calculator. Worked historical Sol examples below retain their original model and workload.
Per 1M tokens, USD. GPT-6 rates are short-context Standard; Claude rates are Anthropic's published standard rates.
| Model | Input / 1M | Cached input / 1M | Output / 1M | Source |
|---|---|---|---|---|
| GPT-6 Luna | $0.10 | $0.01 | $0.50 | OpenAI |
| GPT-6 Sol | $2.00 | $0.20 | $10.00 | OpenAI |
| GPT-6 Astra | $10.00 | $1.00 | $50.00 | OpenAI |
| Claude Opus 5.5 | $4.00 | $0.20 * | $20.00 | Anthropic |
| Claude Sonnet 5.5 | $2.00 | $0.10 * | $10.00 | Anthropic |
| Claude Haiku 5.5 | $0.10 † | $0.01 * | $0.50 | Anthropic |
| Claude Fable 5.1 | $10.00 | $0.25 * | $50.00 | Anthropic |
| Claude Mythos 5.1 (invite only) | $10.00 | $0.25 * | $50.00 | Anthropic |
* Cache-hit rate. Cache writes (1.25–2× base input) are not modeled — see the caveat above. Sonnet 5.5 gets a 0.05× hit discount; Fable 5.1 / Mythos 5.1 get a deeper 0.025× hit discount ($0.25 vs the standard 0.1×).
† Haiku 5.5 is priced by prompt length: a prompt over 100,000 tokens bills the whole request at $0.50 input / $0.05 cache hit / $2.50 output per 1M. The rates shown are the ≤100K band; the calculator switches bands automatically.
Concrete workload — 30,000 input + 8,000 output tokens per request, 20,000 requests/month, 40% cached input, Standard tier:
| Per request | Per day | Per month | Per year | |
|---|---|---|---|---|
| GPT-6 Luna | $0.00592 | $3.95 | $118.40 | $1,420.80 |
| GPT-6 Sol | $0.11840 | $78.93 | $2,368.00 | $28,416.00 |
| GPT-6 Astra | $0.59200 | $394.67 | $11,840.00 | $142,080.00 |
| Claude Opus 5.5 | $0.23440 | $156.27 | $4,688.00 | $56,256.00 |
| Claude Sonnet 5.5 | $0.11720 | $78.13 | $2,344.00 | $28,128.00 |
| Claude Fable 5.1 | $0.58300 | $388.67 | $11,660.00 | $139,920.00 |
| Claude Mythos 5.1 | $0.58300 | $388.67 | $11,660.00 | $139,920.00 |
Opus 5.5 at $4,688/month sits squarely between Sol ($2,368) and Astra ($11,840): about 1.98× Sol and costs 39.6% as much as Astra (60.4% lower). In dollars: Opus 5.5 costs $2,320/month more than Sol and $7,152/month less than Astra on this workload. The per-request gap vs Sol is $0.1160 — small per call, $2,320/month at this volume. Remember the caveat: with cache churn, the real Anthropic bill lands somewhat above $4,688.
The newer Claude tiers slot in cleanly. Sonnet 5.5 matches Sonnet 5 and GPT-6 Sol on input and output ($2/$10), but its cache hit is now $0.10 — half of Sol's $0.20 — so this cached workload lands at $2,344/month, $24 below Sol. Fable 5.1 and Mythos 5.1 share the same $10/$50 headline rates as GPT-6 Astra and land at $11,660/month vs Astra's $11,840 here: the deeper 0.025× cache-hit discount ($0.25 vs Astra's $1.00) shaves about 1.5% off. Same caveat as ever for the Claude column — cache-write surcharges aren't in these numbers.
Here's where a plain rate table misleads: OpenAI discounts cached input to 0.1× base; Anthropic discounts cache hits to 0.05× base ($0.20 vs $4.00) — a deeper cut. On the example workload (40% cache), no-cache → cached: Opus 5.5 drops $5,600 → $4,688/month (−16.3%); Sol drops $2,800 → $2,368/month (−15.4%). So hit-heavy caching narrows the gap slightly in Claude's favor.
But the other half of Anthropic's cache story is missing from every calculator on this page: writing to cache costs 1.25–2× the base input rate ($5.00–$8.00/1M for Opus 5.5). If your cache turns over constantly — new documents every request, short-lived prefixes — those write charges eat the hit savings, and can erase them. Our numbers assume your cached tokens were written once and hit many times. If that doesn't describe your workload, treat the Claude column as optimistic.
Output-token share of the example bill: Luna 67.6%, Sol 67.6%, Astra 67.6%, Opus 5.5 68.3%. Output dominates everywhere — and it's the main reason Opus 5.5 lands where it does: its $20/1M output rate is 2× Sol's and the single biggest line item. Two practical reads: (1) if your workload is output-heavy, the cross-vendor ranking is decided almost entirely by output rates; (2) if it's input-heavy with high cache reuse, the vendors' different cache mechanics matter more than the headline input prices — and that's exactly where the write-cost caveat bites.
Math only, no verdicts. This page compares cost arithmetic, not model quality. It doesn't claim GPT-6 or Claude is "better" — and cross-vendor figures are directional estimates, not invoice predictions. Within OpenAI's three tiers the math is exact; across the vendor line, read the caveats.
Because caching mechanics differ by provider. Anthropic's cached-input figure is a cache-hit rate, while cache writes (1.25–2× the base input price) are not modeled in our calculator; token metering details also differ slightly. Treat cross-vendor numbers as directional estimates — within OpenAI the math is exact.
Cache hits and refreshes are billed at $0.20/1M (0.05× the base $4.00 input rate for Opus 5.5). Writing tokens into the cache costs 1.25–2× the base input rate. Our calculator models only the hit rate, so workloads with heavy cache churn will cost more than shown.
Pure math: Opus 5.5 rates are 2× Sol on input ($4.00 vs $2.00) and output ($20.00 vs $10.00), and equal on cached input ($0.20 each). On our example coding-agent workload Opus 5.5 costs $4,688/month versus Sol's $2,368/month — about 1.98×.
On cache hits, Anthropic's 0.05× discount is deeper than OpenAI's 0.1×, so hit-heavy workloads narrow the gap slightly — 16.3% saved versus 15.4% in our example. But the unmodeled cache-write surcharge (1.25–2× base) pushes the other way, so the net effect depends on your cache churn.
Both are verified on our methodology page — Sonnet 5 at $2.00/$0.20/$10.00 and Haiku 4.5 at $1.00/$0.10/$5.00 per 1M — but are not in this page's widget. The newer Sonnet 5.5, Fable 5.1, Mythos 5.1 and Haiku 5.5 are in the widget above. Notably, Sonnet 5.5 matches GPT-6 Sol on input and output ($2.00/$10.00), but its cache hit is $0.10 — half of Sol's $0.20 — so cached workloads price slightly below Sol.
No. Processing availability is model-specific. Claude models are currently modeled only at Standard, with regional processing off and no cache writes. Under Fast, Flex or Batch, their comparison rows show Unavailable instead of applying OpenAI's multipliers. Anthropic's own batch and discount programs are not modeled here.
Independence disclosure: this is an independent cost-estimation tool. It is not affiliated with, sponsored by, or endorsed by OpenAI, Anthropic, or Google. Prices are a snapshot last verified October 10, 2026 and may be outdated — always confirm on the provider's official pricing page before making decisions.