--- title: "Offset your flying's CO₂ with Claude or ChatGPT | TrimCarbon" description: "Ask Claude or ChatGPT for your flying's CO₂, from hours, fuel or your logbook, then offset it on trimcarbon.com. Setup, prompts and the proof, in four steps." url: https://trimcarbon.com/expertise/how-to-offset-co2-with-claude-or-chatgpt language: en --- [Carbon Compass](https://trimcarbon.com/expertise) # How to offset CO₂ with Claude or ChatGPT Ask Claude or ChatGPT what your flying emits, from hours, fuel or your logbook export, then offset it on trimcarbon.com and check the certificate from the chat. Four steps, with the prompts to use. [Jp Valery](https://jpvalery.me/) Oct 15, 2026 5 min read You can now ask Claude or ChatGPT what your flying emits and get the same answer as our [calculator](https://trimcarbon.com/emissions-calculator): 50 hours a year in a Cessna 172 is 4,400 kg of CO₂. The assistant calls TrimCarbon's tools for the figure, and you offset it on trimcarbon.com. **The short answer:** add TrimCarbon to your assistant, ask for your CO₂ from hours, fuel or your logbook, then offset it on trimcarbon.com. Nothing is bought inside the chat. ## Step 1: Add TrimCarbon to your assistant TrimCarbon connects to assistants as an MCP server, the standard way for an assistant to call outside tools. It isn't in the Claude or ChatGPT directories yet, so you add it by its address. Our [setup page](https://trimcarbon.com/ai) has both addresses with a copy button. - **Claude:** open Customize, then Connectors, select Add custom connector, name it TrimCarbon and paste `https://mcp.trimcarbon.com/mcp`. Once you add it on the web or in Claude Desktop, it also works in the mobile apps. Free plans allow one custom connector. - **ChatGPT:** open Plugins, select +, then Add custom MCP server, and paste `https://mcp.trimcarbon.com/chatgpt`. Whether you can add one depends on your ChatGPT plan, region and workspace settings. - **Claude Code, Cursor and other developer tools:** use the Claude address. In Claude Code: `claude mcp add --transport http trimcarbon https://mcp.trimcarbon.com/mcp`. You need no TrimCarbon account for the estimates. ## Step 2: Ask for your CO₂ Ask the way you'd ask a friend at the club. The assistant picks the tool, and the result shows in a small card that you can edit. **From your hours.** "What's the CO₂ of 50 hours a year in a Cessna 172?" gives 4,400 kg a year (4.4 tonnes), at 88 kg of CO₂ an hour. Flew 62 hours instead? Change the hours in the card, and it tells the assistant the new figure. It covers about 60 general-aviation types, by name or ICAO code, at typical cruise fuel flow (about 75% power). **From your fuel.** "How much CO₂ does burning 100 US gallons of avgas release?" gives 831 kg, at the EPA's 8.31 kg per gallon. It takes avgas 100LL, mogas or Jet A, in US gallons, litres or kg. If you lean well, your fuel receipts beat the typical cruise figure, and they work for any aircraft, even one we have no figure for. **From your logbook.** "Work out my CO₂ from my ForeFlight logbook export." The card asks for the file: a ForeFlight, Garmin Pilot or LogTen export, up to 5 MB. It reads the file on your device and never uploads it, to us or to the assistant. You see your CO₂ for the last 12 months and for all flights, by aircraft type. Select "Share these totals in the chat" to give the assistant your hours and CO₂ per type, and nothing else: no registrations, no remarks. If the card can't match a type code, the assistant can estimate it with the closest type you agree on. The figures count the CO₂ from burning the fuel only, as on our website. They leave out the fuel's production and non-CO₂ effects such as contrails. ## Step 3: Offset it on trimcarbon.com **In Claude**, select "See offset prices" in the card. For 4.4 tonnes, it shows a one-time purchase of 5 tonnes for $200 (whole tonnes at $40 each) and, for a yearly figure, our yearly and monthly plans. Choose one and select "Continue on trimcarbon.com". You sign up and pay on our website, where you see the price again before you pay. **In ChatGPT**, the card shows no prices: ChatGPT's plugin rules don't allow selling digital products in the chat. Open our [pricing](https://trimcarbon.com/pricing) page and enter the same figure. Either way, the purchase happens on trimcarbon.com, never in the chat. And before you buy, [cutting your fuel burn](https://trimcarbon.com/expertise/reduce-aircraft-fuel-burn) shrinks the number you offset. ## Step 4: Check your offsets from the chat Connect your TrimCarbon account and the assistant can read your own offsets. The first time you ask about them, it asks you to connect: you sign in on trimcarbon.com and allow it, on a page that names the assistant. The access is read-only: it can't buy, cancel or change anything. Then ask: - "How much CO₂ have I offset with TrimCarbon?" gives your total, by year, and the projects you funded. - "List my TrimCarbon orders" gives each order with its date, kg and status. - "Show my latest certificate" gives the certificate number, the projects behind it with their registries and, where the registry has published them, the retirement serial numbers, plus links to the public certificate and its PDF. The serial numbers let you check the credits yourself: [how to verify a carbon offset on the registry](https://trimcarbon.com/expertise/how-to-verify-carbon-offsets). ## Running a flight school or club? Ask for the whole fleet at once: "Our school flies 600 hours a year in Cessna 172s and 120 hours in a Piper Seminole. What's our CO₂?" The answer is 76,080 kg a year: 52,800 kg from the 172s and 23,280 kg from the [Seminole](https://trimcarbon.com/emissions-calculator/piper-pa-44-seminole) at 194 kg an hour. The card takes up to 25 rows, one per type, so you can adjust the hours before the board meeting. Above 15 tonnes a year, we price fleets with you: [tell us about your fleet](https://trimcarbon.com/contact/high-volume). If your scheduling software offsets each lesson through our [carbon offset API](https://trimcarbon.com/expertise/carbon-offset-api), connect the account that owns it and ask "How much have we offset through the API this month?". ## What TrimCarbon sees Each tool call sends only what the tool needs: aircraft types, hours, fuel amounts, an amount of CO₂ for prices, or a certificate number. Your conversation stays with Claude or ChatGPT, and your logbook file stays on your device. Connecting your account is optional, and you can disconnect it at any time from [your account page](https://trimcarbon.com/account). The details are in our [privacy policy](https://trimcarbon.com/legal/privacy-policy). ## Questions pilots ask **Does it cost anything to use?** No. The connector is free, with or without a TrimCarbon account. You pay only for the offsets you buy on our website. **Is my aircraft covered?** Ask for it by name or ICAO code, for example "Does TrimCarbon have the Piper PA-28 (P28A)?". If we have no figure for it, ask from your fuel instead. **Does offsetting cancel my flight's CO₂?** No. It funds the retirement of carbon credits for the same amount. See [what you can say after offsetting](https://trimcarbon.com/expertise/carbon-neutral-claims-after-offsetting). About the author [Jp Valery](https://jpvalery.me/) Jp Valery is a private pilot with night and float ratings, trained at Lachute Aviation in Quebec, and the founder of TrimCarbon. Every number in these guides shows its arithmetic. [Our story](https://trimcarbon.com/story) ## What does your flying emit? Pick your aircraft and hours to see the CO₂ and what it costs to offset. [Calculate my hours](https://trimcarbon.com/emissions-calculator) Carbon Compass ## Continue exploring [All guides](https://trimcarbon.com/expertise) [Oct 8, 2026 · A carbon offset API for flight schools, clubs and fleets · Offset every lesson, every day's flying or every fuel uplift from your own software. How a carbon offset API works, what it costs, and when a plan is the better fit.](https://trimcarbon.com/expertise/carbon-offset-api) [Oct 7, 2026 · Are carbon offsets a scam? The evidence, from a pilot who sells them · Not as a category. But a 2024 study of 2,346 projects found under 16% of their credits were real emission reductions, and one developer admitted reporting false data. Here are the red flags, and why no offset cancels a flight.](https://trimcarbon.com/expertise/are-carbon-offsets-a-scam) [Oct 5, 2026 · Carbon offsets for pilots: how they work and how to choose credible ones · What a carbon credit is, where offsetting has gone wrong, and five checks to run before you pay to offset your flying.](https://trimcarbon.com/expertise/carbon-offsets-for-pilots)