Conversion factors See all Tools, guides & reports

Our useful guide will make it easier for you to monitor your organisation's carbon usage by helping you convert energy use and carbon emissions into common units. 

Greenhouse gas conversion factors are used to calculate the amount of greenhouse gas emissions caused by energy use. They are measured in units of kg carbon dioxide equivalent**. In order to convert 'energy consumed in kWh' to 'kg of carbon dioxide equivalent', the energy use should be multiplied by a conversion factor.

Example

To convert from litres of petrol to kgCO2e emissions multiply by 2.331, so for example:

200 litres petrol = 200 x 2.331 = 466.2 kgCO2e

Carbon emissions are usually quoted in kgCO2/kWh. If you wish to convert the carbon dioxide factors into carbon (ie kgC/kWh), multiply the figure by 12 and divide by 44.

Defra published updated conversion factors for 2011 - see: Defra - Measuring and reporting environmental impacts

Our publication Conversion factors - Energy and carbon conversion (CTL153) contains these factors along with a spreadsheet to enter your usage and calculate carbon emissions.

Download Conversion factors (CTL153)