{"success":true,"version":"v1","request":{"tool":"get_calculator_schema","calculator_id":"carbon-footprint-driving"},"result":{"entity_type":"calculator","id":"carbon-footprint-driving","calculator_id":"carbon-footprint-driving","canonical_url":"https://tttkmbb.com/weather/carbon-footprint-driving","name":"Driving Carbon Footprint Calculator","title":"Driving Carbon Footprint Calculator – CO₂ per Trip and per Year from Distance, Fuel Economy and Fuel Type","category":"weather","category_name":"Weather & Environment","tool_name":"estimate_driving_carbon_footprint","featured_mcp_tool":false,"description":"Estimates tailpipe CO₂ (and CO₂-equivalent including methane and nitrous oxide) for a car trip from distance and fuel economy or fuel used, using per-litre combustion factors for petrol, diesel and LPG, and scales to a yearly total.","use_when":"You want the CO₂ emissions of a commute, road trip or annual mileage for a petrol, diesel or LPG vehicle, in kilograms and grams per kilometre.","do_not_use_when":"The vehicle is electric or plug-in hybrid (use carbon-footprint-electricity with the kWh consumed), you need lifecycle/well-to-wheel emissions, or you only need the fuel cost (use fuel-cost).","inputs":[{"name":"distance","label":"Trip distance","type":"number","required":true,"max":1000000,"exclusive_min":0,"description":"Distance of one trip in distance_unit.","example":100},{"name":"distance_unit","label":"Distance unit","type":"enum","required":false,"default":"km","values":[{"value":"km","label":"Kilometres","aliases":["kilometre","kilometer","kilometres","kilometers"]},{"value":"mi","label":"Miles","aliases":["mile","miles"]}],"description":"Unit of the distance.","example":"km"},{"name":"fuel_economy","label":"Fuel economy","type":"number","required":false,"max":1000,"exclusive_min":0,"description":"Vehicle fuel economy in fuel_economy_unit. Not needed when fuel_used_liters is given.","example":7},{"name":"fuel_economy_unit","label":"Fuel economy unit","type":"enum","required":false,"default":"l_per_100km","values":[{"value":"l_per_100km","label":"L/100 km","aliases":["l/100km","l/100 km","litres per 100 km","liters per 100 km"]},{"value":"mpg_us","label":"mpg (US gallon)","aliases":["mpg","miles per gallon","us mpg"]},{"value":"mpg_uk","label":"mpg (imperial gallon)","aliases":["uk mpg","imperial mpg"]},{"value":"km_per_l","label":"km/L","aliases":["km/l","kilometres per litre","kilometers per liter","kmpl"]}],"description":"Unit of fuel_economy.","example":"l_per_100km"},{"name":"fuel_used_liters","label":"Fuel used (optional)","type":"number","unit":"L","required":false,"max":100000,"exclusive_min":0,"description":"Litres of fuel burned on the trip, if known; overrides fuel_economy.","example":7},{"name":"fuel_type","label":"Fuel type","type":"enum","required":false,"default":"petrol","values":[{"value":"petrol","label":"Petrol / gasoline (2.31 kg CO₂/L)","aliases":["gasoline","gas","unleaded"]},{"value":"diesel","label":"Diesel (2.68 kg CO₂/L)"},{"value":"lpg","label":"LPG / autogas (1.51 kg CO₂/L)","aliases":["autogas","propane"]}],"description":"Fuel burned; selects the kg CO₂ per litre combustion factor.","example":"petrol"},{"name":"trips_per_year","label":"Trips per year","type":"number","required":false,"default":1,"min":1,"max":100000,"description":"How many times the trip is driven per year (e.g. 230 for a one-way daily commute, 460 for both directions).","example":230}],"outputs":[{"name":"fuel_liters","label":"Fuel per trip","type":"number","unit":"L","decimals":2,"description":"Litres of fuel burned on one trip."},{"name":"co2_kg_per_trip","label":"CO₂ per trip","type":"number","unit":"kg","decimals":2,"description":"Tailpipe carbon dioxide from combustion, fuel_liters × factor."},{"name":"co2e_kg_per_trip","label":"CO₂e per trip","type":"number","unit":"kg","decimals":2,"description":"Tailpipe greenhouse gases including CH₄ and N₂O, CO₂ ÷ 0.994 (EPA 2022 ratio for passenger vehicles)."},{"name":"co2_g_per_km","label":"CO₂ intensity","type":"number","unit":"g/km","decimals":1,"description":"Grams of CO₂ per kilometre driven."},{"name":"co2_kg_per_year","label":"CO₂ per year","type":"number","unit":"kg","decimals":1,"description":"co2_kg_per_trip × trips_per_year."},{"name":"co2e_kg_per_year","label":"CO₂e per year","type":"number","unit":"kg","decimals":1,"description":"co2e_kg_per_trip × trips_per_year."},{"name":"emission_factor_kg_per_liter","label":"Emission factor","type":"number","unit":"kg CO₂/L","decimals":2,"description":"Combustion factor applied for the selected fuel."},{"name":"distance_km","label":"Trip distance","type":"number","unit":"km","decimals":2,"description":"Trip distance in kilometres."}],"input_schema":{"type":"object","properties":{"distance":{"description":"Distance of one trip in distance_unit.","type":"number","maximum":1000000,"exclusiveMinimum":0,"examples":[100]},"distance_unit":{"description":"Unit of the distance.","type":"string","enum":["km","mi"],"default":"km","examples":["km"]},"fuel_economy":{"description":"Vehicle fuel economy in fuel_economy_unit. Not needed when fuel_used_liters is given.","type":"number","maximum":1000,"exclusiveMinimum":0,"examples":[7]},"fuel_economy_unit":{"description":"Unit of fuel_economy.","type":"string","enum":["l_per_100km","mpg_us","mpg_uk","km_per_l"],"default":"l_per_100km","examples":["l_per_100km"]},"fuel_used_liters":{"description":"Litres of fuel burned on the trip, if known; overrides fuel_economy. Unit: L.","type":"number","maximum":100000,"exclusiveMinimum":0,"examples":[7],"x-unit":"L"},"fuel_type":{"description":"Fuel burned; selects the kg CO₂ per litre combustion factor.","type":"string","enum":["petrol","diesel","lpg"],"default":"petrol","examples":["petrol"]},"trips_per_year":{"description":"How many times the trip is driven per year (e.g. 230 for a one-way daily commute, 460 for both directions).","type":"number","minimum":1,"maximum":100000,"default":1,"examples":[230]}},"additionalProperties":false,"required":["distance"]},"output_schema":{"type":"object","properties":{"fuel_liters":{"description":"Litres of fuel burned on one trip. Unit: L.","type":"number","x-unit":"L"},"co2_kg_per_trip":{"description":"Tailpipe carbon dioxide from combustion, fuel_liters × factor. Unit: kg.","type":"number","x-unit":"kg"},"co2e_kg_per_trip":{"description":"Tailpipe greenhouse gases including CH₄ and N₂O, CO₂ ÷ 0.994 (EPA 2022 ratio for passenger vehicles). Unit: kg.","type":"number","x-unit":"kg"},"co2_g_per_km":{"description":"Grams of CO₂ per kilometre driven. Unit: g/km.","type":"number","x-unit":"g/km"},"co2_kg_per_year":{"description":"co2_kg_per_trip × trips_per_year. Unit: kg.","type":"number","x-unit":"kg"},"co2e_kg_per_year":{"description":"co2e_kg_per_trip × trips_per_year. Unit: kg.","type":"number","x-unit":"kg"},"emission_factor_kg_per_liter":{"description":"Combustion factor applied for the selected fuel. Unit: kg CO₂/L.","type":"number","x-unit":"kg CO₂/L"},"distance_km":{"description":"Trip distance in kilometres. Unit: km.","type":"number","x-unit":"km"}}},"formula":"fuel_L = distance_km × L/100km ÷ 100 (mpg converted via 235.215/mpg_US or 282.481/mpg_UK; km/L via 100/(km/L)); CO₂ = fuel_L × factor (petrol 2.31, diesel 2.68, LPG 1.51 kg/L); CO₂e = CO₂ / 0.994; per year = per trip × trips_per_year","method":"Tank-to-wheel combustion factors as of 2024: they match the UK DEFRA/DESNZ 2024 factors for 100 % mineral petrol and diesel and the US EPA values (8,887 g CO₂ per US gallon of petrol = 2.35 kg/L, 10,180 g/gal diesel = 2.69 kg/L) within 2 %. Upstream (well-to-tank) emissions add roughly 20 % and are not included.","sources":[{"name":"US EPA – Greenhouse Gas Emissions from a Typical Passenger Vehicle (8,887 g CO₂/gal petrol, 10,180 g CO₂/gal diesel)","url":"https://www.epa.gov/greenvehicles/greenhouse-gas-emissions-typical-passenger-vehicle","type":"government","retrieved_at":"2026-09-24"},{"name":"UK DESNZ/DEFRA – Greenhouse gas reporting: conversion factors 2024 (fuels per litre, electricity)","url":"https://www.gov.uk/government/publications/greenhouse-gas-reporting-conversion-factors-2024","type":"government","retrieved_at":"2026-09-24"},{"name":"US EPA – Greenhouse Gas Equivalencies Calculator: calculations and references (eGRID 2022 US average 823.1 lb CO₂/MWh; vehicle CO₂/GHG ratio 0.994)","url":"https://www.epa.gov/energy/greenhouse-gases-equivalencies-calculator-calculations-and-references","type":"government","retrieved_at":"2026-09-24"}],"freshness":{"type":"static","max_age_seconds":null,"note":"Deterministic formula with fixed constants; results never go stale. Inputs supplied by the caller determine the output."},"examples":[{"name":"100 km at 7 L/100 km, petrol, 230 trips/year","inputs":{"distance":100,"distance_unit":"km","fuel_economy":7,"fuel_economy_unit":"l_per_100km","fuel_type":"petrol","trips_per_year":230},"expected":{"fuel_liters":7,"co2_kg_per_trip":16.17,"co2e_kg_per_trip":16.27,"co2_g_per_km":161.7,"co2_kg_per_year":3719.1,"emission_factor_kg_per_liter":2.31},"url":"https://tttkmbb.com/api/v1/calculate/carbon-footprint-driving?distance=100&distance_unit=km&fuel_economy=7&fuel_economy_unit=l_per_100km&fuel_type=petrol&trips_per_year=230"},{"name":"30 miles at 30 mpg (US), diesel","inputs":{"distance":30,"distance_unit":"mi","fuel_economy":30,"fuel_economy_unit":"mpg_us","fuel_type":"diesel"},"expected":{"distance_km":48.28,"fuel_liters":3.79,"co2_kg_per_trip":10.14,"co2_g_per_km":210.1},"url":"https://tttkmbb.com/api/v1/calculate/carbon-footprint-driving?distance=30&distance_unit=mi&fuel_economy=30&fuel_economy_unit=mpg_us&fuel_type=diesel"}],"faq":[{"q":"Why is diesel's factor higher if diesel cars emit less?","a":"Diesel contains more carbon per litre (2.68 vs 2.31 kg CO₂), but diesel engines use fewer litres per 100 km; compare grams per kilometre, not per litre."},{"q":"What is the difference between CO₂ and CO₂e here?","a":"CO₂e adds the tailpipe methane and nitrous oxide weighted by global-warming potential; for modern cars that is under 1 % (EPA ratio 0.994), so both numbers are close."},{"q":"Does this include fuel production?","a":"No. Well-to-tank emissions from extracting, refining and transporting the fuel add about 20 % (DEFRA well-to-tank factors); electricity and lifecycle comparisons should include them."}],"tags":["carbon footprint driving","car co2 emissions","co2 per km","fuel emissions calculator","commute emissions"],"related":[{"calculator_id":"carbon-footprint-electricity","reason":"Emissions of electricity use, including EV charging."},{"calculator_id":"fuel-cost","reason":"Cost of the same trip from fuel price and economy."},{"calculator_id":"fuel-economy","reason":"Convert between L/100 km, mpg and km/L."}],"links":{"html":"https://tttkmbb.com/weather/carbon-footprint-driving","markdown":"https://tttkmbb.com/weather/carbon-footprint-driving.md","json":"https://tttkmbb.com/weather/carbon-footprint-driving.json","api":"https://tttkmbb.com/api/v1/calculate/carbon-footprint-driving","schema":"https://tttkmbb.com/api/v1/calculators/carbon-footprint-driving","openapi":"https://tttkmbb.com/openapi.json","mcp":"https://tttkmbb.com/mcp"},"version":"v1","updated_at":"2026-09-24"},"timestamp":"2026-09-24T01:53:52Z"}