# Calcis: LLM Cost Estimator

> See what your LLM prompt will cost before you send it. Works on ChatGPT, Claude, and Gemini.

Canonical page: [https://chrome-stats.com/d/calcis](https://chrome-stats.com/d/calcis)

## Overview

- **ID:** `calcis`
- **Platform:** Firefox
- **Type:** Firefox add-on
- **Status:** Available
- **Publisher:** Ryan Chen
- **Category:** web-development,alerts-updates
- **Version:** 1.1.0
- **Last updated:** 2026-04-29
- **First published:** 2026-04-24
- **Size:** 48 KB
- **Data as of:** 2026-09-11
- **Store listing:** [Firefox Add-ons Store](https://addons.mozilla.org/firefox/addon/calcis/)
- **Website:** [https://www.calcis.dev](https://www.calcis.dev/)
- **Privacy policy:** [https://addons.mozilla.org/firefox/addon/calcis/privacy/](https://addons.mozilla.org/firefox/addon/calcis/privacy/)

## Description

Calcis shows you what an LLM API call will cost before you send it: right inside ChatGPT, Claude, and Gemini.

As you type a prompt, Calcis estimates the token count, predicts the output length, and shows the total cost in a small overlay near the input box. The estimate updates live as you type.

Features:
- Auto-detects which model you have selected
- Auto-detects effort/reasoning level
- Shows input tokens, predicted output tokens, and cost
- Shows cost at 1,000 requests/month for at-scale planning
- Works on <a href="https://prod.outgoing.prod.webservices.mozgcp.net/v1/20e01e30ea25078cea902794aa1e958707e366e9d854536f80d3480d0584470a/http%3A//chat.openai.com" rel="nofollow">chat.openai.com</a>, <a href="https://prod.outgoing.prod.webservices.mozgcp.net/v1/68a188960f04e2a84c1f04ab562a849360a490d4e86c75e7c7be3ab59437f37d/http%3A//chatgpt.com" rel="nofollow">chatgpt.com</a>, <a href="https://prod.outgoing.prod.webservices.mozgcp.net/v1/749f55679c25c240feed4c33d337c9a6fd364a96bdf82dafdc769bc8883d8fcd/http%3A//claude.ai" rel="nofollow">claude.ai</a>, <a href="https://prod.outgoing.prod.webservices.mozgcp.net/v1/187ed18c48fe4e37708681edcdd7edf8bc86c3385debd75875ddac265b398f10/http%3A//gemini.google.com" rel="nofollow">gemini.google.com</a>
- Non-intrusive overlay that can be collapsed or dismissed
- Your prompts are never stored or logged by the extension

Setup:
1. Get an API key at calcis.dev/dashboard
2. Click the Calcis extension icon and enter your API key
3. Open ChatGPT, Claude, or Gemini and start typing

Powered by the same estimation engine as calcis.dev.

## Rankings

- #137,459 — Overall
- #115 — cost

## Permissions and access

### Permissions

- `storage`
- `activeTab`

### Host permissions

- `https://chat.openai.com/*`
- `https://chatgpt.com/*`
- `https://claude.ai/*`
- `https://gemini.google.com/*`
- `https://www.calcis.dev/*`

### Content script matches

- `chat.openai.com`
- `chatgpt.com`
- `claude.ai`
- `gemini.google.com`

## Safety

- **Risk impact:** Very high risk impact
- **Risk likelihood:** High risk likelihood

### Analysis details

- Request access to the following domains: openai.com, chatgpt.com, claude.ai, google.com, calcis.dev
- This extension has low user count. Unpopular extensions may not be stable or safe.

> Some risk analysis details are omitted from this free response. [Upgrade to view the full analysis](https://chrome-stats.com/pricing).

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Source: [Chrome-Stats](https://chrome-stats.com/d/calcis)