Token counting
When the server proxy is configured, the counter calls Anthropic count_tokens with model: "claude-fable-5". If the API is unavailable, the UI keeps working in estimate mode and labels the result.
Cost calculator
Claude Fable 5 Cost Calculator
Estimate what Claude Fable 5 actually costs with caching, batch, and subscription credits included.
Default result is server-rendered: $20.00 for 1M input + 200K output.
Simple mode for fast estimates
Advanced cache billing buckets
Fallback kept out of calculator
Effective cost vs Opus 4.8
Fable 5 uses a higher base price than Opus 4.8. This page does not claim a fixed task-level multiplier because output length, cache use, and routing decide the bill.
How caching and Batch stack
Advanced caching splits regular input, 5-minute writes, 1-hour writes, cache reads, and output. Batch and US-geo modifiers are then applied to the calculated base.
Subscription usage credits
The credit estimate is a planning conversion. It is not an API invoice and it should not be used to reconcile your bill.
Fallback billing is intentionally not a calculator toggle. See Fable 5 specs and fallback notes.
Methodology
How we calculate
Cost formula
Regular input, cache writes, cache reads, and output are priced separately. Batch and US-geo modifiers are applied after the base cost, matching the current MVP contract.
Data handling
The MVP proxy does not store pasted text. It only needs request status, rough character bucket, and timing for abuse and reliability checks.
Corrections
Pricing changes should be fixed in PRICING_CONFIG, rebuilt, and noted with a new last-verified date.
Last updated
June 12, 2026
Pricing constants are isolated in one config file and should be rechecked before launch.
Sources
Boundary
Estimates are for planning. Check your Anthropic invoice and current pricing before committing spend.
FAQ
Does the calculator include prompt caching?
Yes. Simple mode maps cache hit percentage to cache-read tokens; Advanced mode exposes the actual billing buckets.
Does this include fallback routing?
No. Fallback behavior belongs on the model page because the billing path depends on current Anthropic behavior and configuration.