How does a bus operator calculate emissions per passenger-km?
Multiply the diesel bought for the fleet by 2.68 kg CO2 per litre and divide by passenger-km: passengers carried times km per trip, from tickets or seat logs. Occupancy decides the result, so report per bus-km as well.
Data needed
- Diesel from fuel invoices or fuel cards.
- Passengers per trip, from tickets or headcounts.
- Trip distance from the route schedule or GPS.
Two figures
Per bus-km shows fuel efficiency; per passenger-km shows how well buses are filled. Clients and schools want the second.
For clients
A company hiring your buses for staff reports them in Scope 3, Category 7. A per passenger-km figure from real diesel is better than a default factor.
Worked example: bus fleet (one month, illustrative inputs)
- Diesel: 30,000 litres x 2.68 = 80,400 kg CO2
- Passenger-km: 1,000,000
- Per passenger-km: 80,400 / 1,000,000 = 0.0804 kg CO2
Inputs are illustrative; use fuel records and ticket counts.
What Senseible does here
Senseible reads fuel invoices and fuel card statements (diesel 2.68 and CNG 2.69 kg CO2, IPCC 2006 defaults) into a fingerprinted Scope 1 record. Hired transport goes to the Scope 3 evidence trail, and distance or tonne-km estimates are labelled as estimates.
Sources: IPCC 2006 Guidelines, Volume 2 Energy (fuel defaults), GHG Protocol Corporate Standard, GLEC Framework for logistics emissions (Smart Freight Centre)
Last reviewed 2026-10-21.