Claude API cost calculator: what Opus 5, Fable 5, Sonnet 5 and Haiku 4.5 cost for your volume

Turn “Opus 5 costs half of Fable 5” into a real monthly figure for a specific application, and show what the same work would cost on every other model in the lineup.

Price Your Own Workload

Claude API cost calculator: what Opus 5, Fable 5, Sonnet 5 and Haiku 4.5 cost for your volume

Enter your monthly request volume and typical prompt and response sizes. This prices the same workload on every current Claude model using Anthropic's published per-million-token rates, including prompt-cache reads and the Batch API discount.

Uses: Model · API requests per month · Average input tokens per request · Average output tokens per request · Share of input served from prompt cache · Use the Batch API (50% off, asynchronous)

A planning estimate using published list prices, not a quote and not a bill. Cache writes, server-side tool charges, fast mode and data-residency multipliers are excluded, and list prices change — confirm against Anthropic's pricing page and your own console usage before budgeting.

ModelAPI requests per monthOne Messages API call each. An agent that makes 20 calls per user task counts as 20.Average input tokens per requestSystem prompt plus conversation plus any documents or tool results you send.Average output tokens per requestIncludes thinking tokens and tool-call arguments, not just the visible answer.Share of input served from prompt cache%Cache hits cost a tenth of the base input rate. Cache writes are not modelled — see the limitations.Use the Batch API (50% off, asynchronous)Only for work that can wait — batch requests are processed asynchronously.

Example — adjust the inputs above for your situation

About $9,750 a month on Claude Opus 5.

At 100,000 requests a month averaging 12,000 input and 1,500 output tokens, that is $9,750 a month less than Claude Fable 5 — about 50% of the flagship's price for this mix. The cheapest option shown is Claude Haiku 4.5 at $1,950.

Claude Opus 5 — estimated monthly cost: $9,750
Cost per 1,000 requests: $97.50
Same workload on Claude Fable 5: $19,500
Same workload on Claude Sonnet 5 (introductory rate): $3,900
Same workload on Claude Sonnet 5 (from September 1, 2026): $5,850
Same workload on Claude Haiku 4.5: $1,950
Tokens per month (input / output): 1,200,000,000 / 150,000,000

※ Rates are Anthropic's published per-million-token prices as of July 24, 2026. Prices change; check the pricing page before budgeting against this.
※ Cache WRITE cost is not included — a cached prefix is charged at 1.25× (5-minute) or 2× (1-hour) base input the first time it is stored. Long-running agents amortise that; short sessions do not.
※ Server-side tools are extra: web search is billed at $10 per 1,000 searches, and Claude Managed Agents adds $0.08 per session-hour of runtime.

How this is calculated

Pure arithmetic against published list prices. For each model the tool computes monthly cost as: requests × [ input tokens × ((1 − cache share) × base input rate + cache share × cache-hit rate) + output tokens × output rate ] ÷ 1,000,000, then halves the total when the Batch API is selected. Base input, output and cache-hit rates are transcribed directly from Anthropic's pricing page (retrieved July 24, 2026); the cache-hit rate is 0.1× base input, and the Batch API is a flat 50% discount on input and output. Sonnet 5 appears twice because its introductory $2/$10 rate is scheduled to become $3/$15 on September 1, 2026. No token counting, estimating or modelling happens anywhere — the tool multiplies your numbers by their numbers.

Data as of July 23, 2026 · verified July 23, 2026 · v1

Assumptions, limitations & sources

Assumptions

· Rates are Anthropic first-party Claude API list prices in USD as published on July 24, 2026, with no negotiated or enterprise discount applied.
· Cache share means the percentage of input tokens served as cache hits, billed at 0.1× the base input rate.
· The Batch API discount is applied as a flat 50% to both input and output, matching the published batch price table.
· One request is one Messages API call; agentic loops that make many calls per user task should be entered as many requests.

Limitations

· Cache WRITE cost is not modelled. Storing a cached prefix costs 1.25× base input for the 5-minute cache or 2× for the 1-hour cache, charged the first time. Steady-state agents amortise that away; short-lived sessions do not.
· Server-side tool charges are excluded: web search is billed separately at $10 per 1,000 searches, and Claude Managed Agents adds $0.08 per session-hour of runtime.
· The fast-mode premium ($10/$50 per MTok on Opus 5) and the 1.1× US-only data-residency multiplier are not applied.
· Claude 4.7-generation models and later use a newer tokenizer that produces roughly 30% more tokens for the same text — so a token count measured on an older model understates cost here.
· List prices change. This is a planning estimate, not a quote or a bill.

Sources

Claude platform pricing — per-model input, output, cache and batch rates — Anthropic, checked July 23, 2026 · Rates transcribed verbatim; no conversion or rounding applied to the inputs.
Claude models overview — context windows, max output, model IDs and pricing summary — Anthropic, checked July 23, 2026
Effort parameter documentation — the five effort levels and their token-cost tradeoff — Anthropic, checked July 23, 2026

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The story behind this tool

Technology

Anthropic ships Claude Opus 5 at half the price of its flagship — and puts a cost dial in the API

Claude Opus 5 arrived July 24 at $5 per million input tokens and $25 per million output — half what Fable 5 costs — with a 1M-token context window and five effort levels that let you trade capability for token spend. Here is what changes, what does not, and what it costs for your own workload.