Calcis: LLM Cost Estimator

Name: Calcis: LLM Cost Estimator
Author: Ryan Chen

By: Ryan Chen

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

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Install

Features & Capabilities

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 chat.openai.com, chatgpt.com, claude.ai, gemini.google.com
Non-intrusive overlay that can be collapsed or dismissed
Your prompts are never stored or logged by the extension

Setup:

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

User Growth & Download Statistics

Add-on

By:

Ryan Chen

Daily users:

Version:

1.1.0 Last updated: 2026-04-29

Version code:

6240401

Creation date:

2026-04-24

Risk:

Permissions:

Host permissions:

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

Content scripts matches:

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

Size:

48.25KB

Email:

ca*****@gmail.com

URLs:

Website ,Privacy policy

Full description:

Source:

Firefox Add-ons Store

Data ingested on:

2026-06-03

Compare stats and ranking:

Ranking

# 99,189 ▲ 269

Other rankings

#19 in cost keyword 9

For Developers

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Contact the developer

Chrome-Stats does not own this Firefox add-on. Please use these information below to contact the Firefox add-on developer.

Developed by:

Ryan Chen

Firefox Add-ons Store

https://addons.mozilla.org/firefox/addon/calcis/

Email:

ca*****@gmail.com

Website:

https://www.calcis.dev

Is Calcis: LLM Cost Estimator Safe?

Risk impact

Risk impact measures the level of extra permissions an extension has access to. A low risk impact extension cannot do much harms, whereas a high risk impact extension can do a lot of damage like stealing your password, bypassing your security settings, and accessing your personal data. High risk impact extensions are not necessarily malicious. However, if they do turn malicious, they can be very harmful.

Calcis: LLM Cost Estimator requires some sensitive permissions that could impact your browser and data security. Exercise caution before installing.

Risk impact analysis details

Critical Request access to the following domains: openai.com, chatgpt.com, claude.ai, google.com, calcis.dev
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Risk likelihood

Risk likelihood measures the probability that a Firefox add-on may turn malicious. This is determined by the publisher and the Firefox add-on reputation on Firefox Add-ons Store, the amount of time the Firefox add-on has been around, and other signals about the Firefox add-on. Our algorithms are not perfect, and are subject to change as we discover new ways to detect malicious extensions. We recommend that you always exercise caution when installing a Firefox add-on.

Calcis: LLM Cost Estimator is recently added, and hasn't been around long enough for us to gather enough data to accurately assess its risk level.

Risk likelihood analysis details

High This extension has low user count. Unpopular extensions may not be stable or safe.
Medium **** ********* *** ******* ** *** **** * ******* *** ******* *** *** ** ****** ** *****
Medium **** ********* *** ***** ** *** **** * ******* *** ********** *** *** ** ****** ** *****