Bus
Calculate bus and coach travel emissions on the Calculation API with one of the bus methodologies below.
Choose a methodology
| Methodology | Coverage | Basis | Inputs you need | Notes |
|---|---|---|---|---|
| DEFRA 🇬🇧 | Local buses inside and outside London, and coaches | UK government DEFRA Conversion Factors | origin and destination or distance_in_km; optional bus_type, energy_scope, methodology_version | Pin a factor year with methodology_version |
| SQUAKE | Not stated | SQUAKE methodology with operator-specific data | origin and destination or distance_in_km; optional operator_name, fuel_type | Operator-specific factors for supported operators |
Both methodologies support audit mode and accept provider-prefixed stop IDs such as flixbus:2006 as origin and destination.
How to decide
- You know the bus operator: SQUAKE uses
operator_namefor a more accurate result when the operator is on its supported list. - You know the vehicle's fuel: SQUAKE takes a
fuel_type, such aselectricityorhydrogen. - You need DEFRA's bus categories, a factor year or an energy scope: DEFRA takes
bus_type,methodology_versionandenergy_scope.