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EV & transport calculator

Transport emissions calculator: car, EV, bus, train, plane or ferry?

Compare the CO₂ of one trip by petrol, diesel, hybrid or electric car (on your grid), bus, coach, train, plane, ferry, motorbike or e-bike, per passenger and in total.

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Results

Petrol car emits 169 kg per person, 13× more than electric train (your grid). Switching would save 156 kg CO₂e for your group.
Petrol car: per person
169kg CO₂e
900 km return
Whole group
169kg CO₂e
1 traveller
Per passenger-km
188g CO₂e/pkm
Lowest-carbon option
Electric train (your grid)
14 kg per person
Saving if you switch
156kg CO₂e
Plane for this trip
239kg CO₂e
domestic band, 266 g/pkm incl. radiative forcing
Electric train
13.6kg CO₂e
Romania grid 251 g/kWh
Trees to absorb (1 yr)
8trees
CO₂e per person for this trip (kg) · 900 km
Emission factors (g CO₂e per passenger-km)

All modes for this trip

Modeg CO₂e/pkmPer personGroup of 1vs your mode
E-bike (electricity only)32.7 kg2.7 kg−98%
Electric train (your grid)1514 kg14 kg−92%
Ferry (foot passenger)2321 kg21 kg−88%
Long-distance coach3532 kg32 kg−81%
Electric car (EV)4742 kg42 kg−75%
Diesel train9081 kg81 kg−52%
Local bus120108 kg108 kg−36%
Hybrid car (petrol)129116 kg116 kg−31%
Motorbike (medium)140126 kg126 kg−26%
Ferry (with car, per passenger)157141 kg141 kg−17%
LPG car158142 kg142 kg−16%
Taxi (1.4 passengers)180162 kg162 kg−4%
Diesel car182163 kg163 kg−4%
Petrol car188169 kg169 kg+0%
Plane (domestic, economy)266239 kg239 kg+41%
  • Factors are well-to-wheel CO₂e (fuel production + combustion), based on UK DESNZ/DEFRA 2024 conversion factors and EEA averages; bus, coach and ferry assume average occupancy.
  • Cars: fuel consumption × 2.69 kg/L petrol, 3.13 kg/L diesel. EVs: kWh × 1.10 charging losses × 251 g/kWh (Romania average). Car emissions are divided among the travellers.
  • Flights: per-passenger-km factor for the distance band × 1.08 routing uplift, including non-CO₂ effects (radiative forcing ×1.7). Short flights burn proportionally more fuel at take-off.

How this transport emissions calculator works

Choosing how to travel is one of the few decisions where a single choice can change your emissions tenfold. This calculator compares every common mode for one specific trip (your distance, your number of travellers, your car’s real consumption and your country’s electricity grid), so you see the actual kilograms, not just abstract rankings.

Cars are modelled from first principles: litres or kWh per 100 km times a well-to-wheel factor (fuel extraction, refining and combustion), divided by the number of people in the car. Electric cars, electric trains and e-bikes use the latest average carbon intensity of the grid you select. Public modes use average-occupancy factors based on the UK DESNZ/DEFRA 2024 conversion factors and EEA data. Flights use DEFRA’s distance bands and cabin classes, an 8% uplift for indirect routing and holding patterns and, optionally, the 1.7 radiative-forcing multiplier for non-CO₂ effects.

The formula

Trip CO₂e per person = distance × factor (kg CO₂e per passenger-km)

Car: factor = L/100 km ÷ 100 × fuel factor ÷ travellers (petrol 2.69, diesel 3.13 kg/L) EV: factor = kWh/100 km ÷ 100 × 1.10 × grid g/kWh ÷ 1000 ÷ travellers Flight: factor = band factor (with RF) × 1.08 Train: factor = Wh per passenger-km × grid g/kWh ÷ 10⁶

Worked example: Bucharest to Cluj and back

The default trip is 450 km each way (900 km return), one traveller, petrol car at 7.0 L/100 km, Romanian grid:

  • Petrol car: 7.0 ÷ 100 × 2.69 = 0.188 kg/km → 900 km × 0.188 = 169 kg CO₂e
  • Domestic flight: 0.246 × 1.08 = 0.266 kg/pkm → 239 kg
  • Electric car: 17 kWh/100 km × 1.10 × 251 g/kWh = 47 g/km → 42 kg
  • Coach: 35 g/pkm → 32 kg
  • Electric train at 60 Wh/pkm: 0.06 × 251 = 15 g/pkm → 14 kg

The train emits about 13 times less than driving alone. With four people in the petrol car its per-person figure drops to 42 kg, the same as a solo EV.

How to read the results

  • Per person is the fair figure for comparing modes; whole group matters when you decide how a family or team travels.
  • g CO₂e per passenger-km is the intensity of each mode, independent of distance.
  • The verdict compares your planned mode with the lowest-carbon realistic option: e-bikes are only suggested up to 60 km, local buses up to 80 km, and surface modes are excluded for intercontinental distances.

Typical emission factors (well-to-wheel, per passenger-km)

Mode g CO₂e/pkm Notes
Walking, cycling ≈ 0 Food energy ignored
E-bike 1–10 Electricity only
Electric train 2–40 Depends on grid
Long-distance coach 30–35 High occupancy
Electric car, 1 person 10–130 Grid from France to Poland
Diesel train 60–110
Urban bus 100–130 Average occupancy
Petrol / diesel car, 1 person 160–220 6–8 L/100 km
Long-haul flight, economy 150–160 Incl. radiative forcing
Domestic flight 250–270 Take-off dominates
Long-haul business class 400–470 More floor space per seat

Tips to travel with less CO₂

  1. Take the train for trips under ~1,000 km in Europe. Door-to-door times are often similar to flying.
  2. Fill the car. Emissions per person fall in direct proportion to occupancy; car-sharing is the quickest win.
  3. Fly economy and non-stop. Business class roughly triples your share; take-off and landing make short connecting flights especially wasteful.
  4. Drive efficiently. Keeping to 100–110 km/h on the motorway instead of 130 cuts fuel use by 15–20%.
  5. Go electric on a clean grid, and check the EV vs petrol calculator for lifetime costs too.

Limitations

Factors are averages: a full coach or a packed train performs much better than the average, an empty one far worse. Car factors assume your stated consumption is real-world, not the official test value (real-world is usually 10–25% higher). Vehicle and infrastructure manufacturing are excluded unless you tick the embodied-emissions option for cars. Ferry factors vary hugely by vessel type. Non-CO₂ aviation effects are scientifically uncertain, and the 1.7 multiplier is a policy convention.

Method & assumptions

Trip CO₂e = distance × emission factor per passenger-km. Cars are modelled from your own fuel or electricity consumption and divided by the number of travellers; public modes use average-occupancy factors. Flights use the DEFRA distance bands (domestic < 500 km, short-haul up to 3,700 km, long-haul beyond) with cabin-class weighting (business seats take more floor area), an 8% detour uplift and optionally the 1.7 radiative-forcing multiplier for contrails and NOₓ. Electric trains and e-bikes use your grid's average carbon intensity.

Frequently asked questions

Is it better for the climate to fly or drive?
Driving alone in a petrol car emits roughly 170–200 g CO₂e per km including fuel production; a short domestic flight emits about 250 g per passenger-km once non-CO₂ warming is counted. With two or more people in the car, or with an EV, driving almost always wins. On long distances where a train is available, rail beats both by a factor of 5–15.
How much CO₂ does a train emit per km?
An electric train uses roughly 40–100 Wh per passenger-km. On the EU-average grid that is 10–20 g CO₂e per passenger-km; in France or Sweden it is under 5 g. Diesel trains emit 60–110 g per passenger-km. The UK national rail average (DEFRA 2024) is about 35 g.
How much CO₂ does an electric car emit per km?
An EV using 17 kWh per 100 km plus 10% charging losses emits 19 kWh × grid intensity per 100 km: about 45 g/km in Romania, 60 g/km in Germany, 8 g/km in France and 130 g/km in Poland. Manufacturing the battery adds roughly 20–30 g/km over the car's life, which you can include with the advanced toggle.
Why do flight emissions include radiative forcing?
Aircraft emit CO₂, nitrogen oxides and water vapour at altitude, which form contrails and ozone. These non-CO₂ effects roughly double the short-term warming of aviation. DEFRA recommends multiplying the CO₂ factor by 1.7; you can switch this off to report CO₂ only.
Is a bus or coach greener than a car?
A long-distance coach is one of the lowest-carbon modes at around 30–35 g per passenger-km because it is usually well filled. Urban buses average about 100–120 g per passenger-km because they run nearly empty at off-peak times; at rush hour they are far better than a car.
How do I calculate emissions for a business trip report?
Multiply the distance by the mode's factor per passenger-km. The DEFRA/DESNZ conversion factors are the most widely used set and are what this calculator approximates. For cars, use actual fuel bought (litres × kg CO₂e per litre) when known; it is more accurate than distance.

Sources & references

  1. UK DESNZ — Greenhouse gas reporting: conversion factors 2024 (business travel, passenger vehicles, WTT)
  2. European Environment Agency — Transport and environment report: rail and waterborne transport
  3. ICCT (2021). A global comparison of the life-cycle greenhouse gas emissions of combustion engine and electric passenger cars
  4. Lee, D.S. et al. (2021). The contribution of global aviation to anthropogenic climate forcing for 2000 to 2018. Atmospheric Environment 244

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