Official data

Emission factors, explained

An emission factor converts an everyday quantity — a kWh of electricity, a kilometre flown, a kilogram of beef — into kilograms of CO2e. These pages publish the official figures BlocCarbon calculates with, straight from the UK DESNZ 2026 conversion factors, Agribalyse (ADEME/INRAE) and The Big Climate Database (CONCITO), each with context and worked examples. See our methodology for how factor sets are versioned.

Energy

• UK grid electricitykgCO2e per kWh
• Natural gaskgCO2e per kWh (gross CV)
• Heating oilkgCO2e per litre
• LPGkgCO2e per litre

Travel

• National rail travelkgCO2e per passenger-km
• London UndergroundkgCO2e per passenger-km
• Local bus travelkgCO2e per passenger-km
• Coach travelkgCO2e per passenger-km
• Taxi journeyskgCO2e per passenger-km
• Average carkgCO2e per km
• Domestic flights (UK)kgCO2e per passenger-km (with RF)
• Short-haul flights (economy)kgCO2e per passenger-km (with RF)
• Long-haul flights (economy)kgCO2e per passenger-km (with RF)

Hotels

• UK hotel nightkgCO2e per room-night

Food

• BeefkgCO2e per kg
• ChickenkgCO2e per kg
• CheesekgCO2e per kg
• SalmonkgCO2e per kg
• MilkkgCO2e per kg
• BreadkgCO2e per kg
• TomatoeskgCO2e per kg
• LentilskgCO2e per kg

Freight

• HGV road freightkgCO2e per tonne-km
• Van delivery freightkgCO2e per tonne-km