# Fable 5.2 vs Opus 5.5 cost calculator: run it free, or from your agent

Cost per task and per month on Fable 5.2, its fast mode and Opus 5.5, with each price linked to Anthropic.

## Prompt

Use looot to compare Claude Fable 5.2 and Opus 5.5 cost for my task: [input tokens] input and [output tokens] output tokens per task, [tasks] tasks a month. 1. Set up https://looot.ai/skill.md. 2. Read today's prices from https://platform.claude.com/docs/en/about-claude/models/overview and https://www.anthropic.com/claude-fable-and-mythos-5-2 with the page to markdown job. 3. Work out cost per task and per month for Fable 5.2, its fast mode and Opus 5.5. 4. Return one table with each price's source link.

## What it needs

Input and output tokens per task, tasks per month, and optionally a cache read share and the Batch API

## What comes back

- cost per task on Fable 5.2, Fable 5.2 fast mode and Opus 5.5
- cost per month on each
- each price with a link to the Anthropic page it comes from
- a copyable model routing template

## Endpoints and providers

None. The tool on the web page runs in the browser and calls no endpoint.

## What it costs

Nothing. The tool on the web page runs in the visitor's browser: no account, no API call and no limit per hour. The prompt above runs the same job from your own looot account with current data, billed per call.

## Price a switch

See what moving one task from Opus 5.5 to Fable 5.2 adds to the monthly bill before you change the model id.

## Decide on fast mode

Fast mode costs twice the standard Fable 5.2 price per token. See that difference on your own volume.

## Budget an agent

Type the tokens of one agent task from your logs and the runs per month. Cache reads and batch are optional.

## Plan routing

Copy the routing template: default model, when to move up, when to orchestrate or advise, each line linked to Anthropic.

## How does Fable 5.2 pricing compare with Opus 5.5?

At Anthropic's published prices, Fable 5.2 costs twice what Opus 5.5 costs per token, for input and for output. The calculator shows both price lists with links to Anthropic and the cost of your own task on each.

## What does Fable 5.2 fast mode cost?

Twice the standard Fable 5.2 price per token. Anthropic says fast mode speeds up token generation by up to 2.5 times. Both facts are on Anthropic's Fable and Mythos 5.2 page, linked under the calculator.

## Which model should I start with?

Anthropic's models overview says to start with Opus 5.5 for most workloads and to use Fable 5.2 for demanding reasoning and long-horizon agentic work, or when your evals on Opus 5.5 at higher effort still fall short.

## How do cache reads change the cost?

Anthropic's models overview says prompt cache reads cost 2.5% of the base input price on Fable 5.2 and 5% on Opus 5.5. Set the share of input read from cache and the calculator prices that part at the cache read rate.

## Can I combine fast mode, batch and cache reads?

The two Anthropic pages this calculator cites do not say. When you pick a combination they do not price, the column shows Anthropic does not say instead of a guess.

## Where do the token counts come from?

From you. The calculator has no token estimates of its own. Take the input and output tokens of a real task from your logs or usage reports and type them in.

## What is not included?

Cache writes, long-context prices and per-platform prices. Anthropic's models overview points to its pricing page for those, and the calculator links to it.

## Is the calculator free?

Yes. It runs in your browser, needs no account and makes no API call. Nothing you type is sent anywhere.

## Related tools

- /free-tools/llm-token-cost-calculator
- /free-tools/ai-agent-cost-estimator
- /free-tools/ai-model-comparison

## Last reviewed

2026-11-10.