2019 UK Defra Carbon Conversion Factors Download

Carbon Emissions Factors

Hot off the press are the new 2019 UK Defra carbon conversion factors download - the full set of which you can download fast HERE

These are UK government carbon conversion factors for use from June 2019 onwards.

Need help applying the 2019 UK Defra carbon conversion factors?

Need help or advice about when and how to use these, which replace the 2018 carbon conversion factors?  Or want to discuss different aspects of how to apply 2019 carbon factors to your organisation's circumstances?  We're here to help and love to discuss carbon problems!  Please ring us on 020 0960054 (ask for Emma or Will) and you can email us with your queries here too.

What's new this year?

Fuels, WTT - fuels and fuel properties

In 2019 update, the government has updated the “natural gas” factor to account for the limited biogas content contained in the natural gas received through the gas mains grid network in the UK.

There is also a "natural gas (100% mineral blend)" factor which does not contain any biogas content.

In addition, there is a method change to now use the NAEI values for the composition of natural gas.

Furthermore, additional fuel properties calorific values for fuels in alternative units (kWh/litre) are added in this year.


The method change in the composition of natural gas causes a change to the fuel properties of natural gas which affects gas unit conversions and thus there is a reduction in the corresponding factors (based on mass basis only).

Vans (LGVs)

1. The payload capacity assumptions have been improved – these are now based on real registrations data for UK registered vans taken from EEA CO2 monitoring database files (for 2012-2017 registrations), available from the EEA's website.

2. The way the gCO2/km for different petrol and diesel van sizes is calculated has also been changed; previously this was based on a static relative figure based on older NAEI data (since the NAEI has had only a single size category for several years). This has now been revised, so that the relative CO2/km performance is now also based upon CO2/km data derived from the same EEA CO2 monitoring database source as the payload capacity information.

Other implications:

  1. Since the resulting payload capacities are lower, this increases the emissions per tonne-km for vans.
  2. This results in some changes in the relative (and therefore also absolute) gCO2/km emissions for different petrol and diesel size classes.

Need help with the 2019 UK Defra carbon conversion factors download?

We created this carbon conversion factors download to make it easy to get hold of the 2019 carbon conversion factors published in May or June each year.  If you have any difficulty with our 2019 carbon conversion factors download, please get in touch and we can send them by email.

Should you use market-based electricity carbon factors or location-based carbon conversion factors from this download for UK grid electricity CO2 reporting?

If you're reporting under the GHG Protocol, market-based carbon conversion factors are recommended.  To do this you need your fuel mix disclosure from your electricity supplier to derive the correct carbon factors.  If you've procured 100% REGO-backed renewable electricity (the genuine renewables energy guarantee of origin certificates should be issued to you, not a statement saying that the supplier has purchased the certificates on your behalf which does not mean you've invested in the UK renewables industry) then you can declare ZERO scope 2 emissions using the GHG Protocol market-based method.

However, BEIS, having taken over from DEFRA, has not issued any reporting guidance since 2013. Therefore organisations such as HESA which gather environmental data for the Higher Education Funding Council for England (HEFCE) stick with the location-based method as per the original 2013 UK government guidance.  Conversely, Carbon Disclosure Project (CDP) requests the market-based method.