Method: Daily round-trip distance is: Round-Trip Distance = One-Way Distance × 2 Annual passenger travel activity is: Passenger-km = One-Way Distance × 2 × Working Days × Employees Annual commuting emissions are: CO₂e = Passenger-km × Emission Factor For example: 15 km one way × 2 × 240 days × 100 employees = 720,000 passenger-km/year At 150 g CO₂e/passenger-km: 720,000 × 150 = 108,000,000 g CO₂e = 108 tCO₂e/year The calculator converts miles to kilometres automatically. For car commuting, ensure the emission factor is expressed per passenger-kilometre. Vehicle-kilometre factors require an occupancy adjustment before use here. Rail, metro, bus and motorcycle factors vary by geography, fuel or electricity source, occupancy and methodology. Walking and cycling may be assigned zero direct operational emissions in some inventories, while lifecycle methodologies may include additional impacts. Use the factor appropriate to the selected reporting boundary. This calculator estimates employee commuting activity only. Business travel and company-owned vehicle emissions should normally be accounted for separately.