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Our conversion factors guide helps you calculate your organisation's carbon emissions - with guidance on how to convert energy use and carbon emissions into common units.

This guide has been updated to use UK Government 2013 conversion factors.

Greenhouse gas (GHG) 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.

Conversion factors 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.

Conversion factors - energy and carbon conversion guide

Defra published updated conversion factors in June 2013.  Our guide to conversion factors contains these GHG conversion factors along with an interactive spreadsheet to enter your usage and calculate carbon emissions.

Download the guide:

Conversion factors - Energy and carbon conversion (CTL153)


Download our interactive Conversion factors calculator - editable spreadsheets (.xlsx) to convert energy units into equivalent carbon dioxide emissions, using Defra's 2013 conversion factors.

Find out more about our carbon footprinting measurement services and Footprint Certification for your organisation.

For further guidance on conversion factors, see Defra's website.

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