GHG conversion factors · the DESNZ set, read to the paragraph
GHG conversion factors:
the UK guide
The UK government GHG conversion factors are the multipliers the Department for Energy Security and Net Zero publishes each June to turn fuel, electricity, travel and waste into kilograms of CO2e.
The 2026 set, published on 11 June 2026, puts UK grid electricity at 0.13096 kgCO2e per kWh — 26% below the 2025 set, mostly a cleaner grid and partly a change of method.
Below: the year rule, the three electricity figures and their scopes, what moved, and the mistakes that move a report most.
The basics
What the conversion factors are, and who owns them
A conversion factor turns something you measured into something you report.
Read the provisions and qualifications
Multiply 10,000 litres of diesel, or 500,000 kWh of grid electricity, by the right factor and the answer is kilograms of carbon dioxide equivalent.
The UK government set does this for fuels, UK electricity, heat and steam, refrigerants, passenger and freight transport, air and sea travel, water, waste, materials, hotel stays and homeworking, among other worksheets.
The methodology paper sorts the activities into the three GHG Protocol scopes, so the same workbook serves Scope 1, 2 and 3.
DESNZ writes the factors for the Environmental Reporting Guidelines, including SECR, and adds a sentence worth carrying: they “may also be used for other purposes, but users do so at their own risk”.
The factors are produced for the department by contractors under the National Atmospheric Emissions Inventory contract, and DESNZ’s statement of compliance with the statistics code says a steering group meets every November to discuss improvements.
They are activity-based: per kWh, per litre, per kilometre.
The methodology paper (¶1.6) separates them from Defra’s spend-based multipliers, which convert pounds spent into emissions and are “primarily intended” for comparing categories of final UK demand, though they can give an initial supply-chain estimate.
A report that mixes the two should say which method produced which line; the carbon accounting reference sets out how the methods fit together.
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Conversion
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Calculation
Module 03 / 04
Factor coverage
Module 04 / 04
Scopes
Tables and tools
Three names, one set
Searches still say “Defra conversion factors” and “BEIS conversion factors”.
Both are older names for the same annual publication, now owned by DESNZ.
The GOV.UK collection lists a set for every year from 2002 to 2026, and does not itself say which one is current.
The 2026 set
What changed in 2026, in DESNZ’s own attribution
The 2026 publication changed the electricity method, dropped a spreadsheet and corrected a file.
Each change is below with the paragraph or row that records it.
| Factor, kgCO2e per kWh | 2025 set (2023 data) | 2026 set (2025 data) | Scope |
|---|---|---|---|
| UK electricity generated, including imports | 0.17700 | 0.13096 | Scope 2 |
| Transmission and distribution losses | 0.01853 | 0.01299 | Scope 3, category 3 |
| Electricity consumed (generated plus losses) | 0.19553 | 0.14396 | Reference only |
Why the factor fell
The major changes report puts the electricity fall at 26% and the losses fall at 30%.
Its row 17 says most of the decrease is grid decarbonisation: −16 percentage points from changes in the grid mix between 2023 and 2024, and −3 from 2024 to 2025.
The remaining 6 to 7 points are methodological changes, improvements and corrections.
Why there are two years of change in one
Until 2025 the electricity factor lagged its publication year by two years; from 2026 it lags by one, using Energy Trends statistics.
The 2025 set used 2023 data and the 2026 set uses 2025 data, so the 2024 data year is skipped (methodology paper ¶3.8).
A trend line drawn straight through 2024 is drawing through a hole.
The change reaches everything that runs on electricity: the major changes report records falls of 23% to 26% in electric car factors, and other rows moved for reasons that have nothing to do with the grid.
International rail rose by more than 150%, the London Underground fell by 44% to 45% and coaches rose by 42% to 43%; homeworking office equipment fell 31% because it had not been updated since 2022; one refrigerant blend was corrected to zero.
DESNZ’s threshold for listing a change is more than 5% for a Scope 1 or 2 source and more than 10% for Scope 3, so the report is the place to check whether any factor you use moved.
Two housekeeping changes complete the picture: the condensed set was not published for 2026, and in July 2026 DESNZ republished the flat file because some well-to-tank values for hybrid, CNG and LPG cars and some hotel-stay values showed 0 instead of blank.
The full set published in June was not revised.
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Electricity movement
Module 02 / 04
Grid mix
Module 03 / 04
Method changes
Module 04 / 04
Time-series break
Calculator
Your electricity under both sets
Enter a year’s kWh and pick the year the electricity was used.
The calculator gives location-based Scope 2 on the generation factor, the grid losses that belong in Scope 3, and the same use priced at the other year’s factor so you can see how much of any year-on-year movement is the factor rather than you.
It shows the consumed factor for reference and says why it is not a Scope 2 number.
Every factor is the Table 9 figure; nothing is rounded beyond what DESNZ prints.
For contracts, certificates and the market-based figure, use the Scope 2 emissions calculator instead.
Factor calculator · 2025 and 2026 sets
Enter a kWh figure to see the emissions.
Every factor used is shown beside its result.
Factors: DESNZ methodology papers, Table 9 (2025 set on 2023 data; 2026 set on 2025 data).
Scope split: 2026 paper ¶¶3.1 and 3.9.
Nothing you enter is stored or sent.
Reporting periods
Which year’s factors: the activity year
The rule is one sentence of the 2026 methodology paper, at ¶1.10: “The 2026 GHG Conversion Factors are for use with activity data that falls entirely or mostly within 2026.”
Read the provisions and qualifications
The 2025 paper says the same of 2025 at ¶1.8, so this is settled drafting, not a one-off.
The factor year follows the activity, not the date you publish or file.
A calendar 2026 year reported in spring 2027 uses the 2026 set — published halfway through the year it describes.
A year to 31 March 2027 has nine months in 2026, so it too takes the 2026 set.
A year to 30 June splits six and six, which “entirely or mostly” does not decide: choose an approach, state it and keep it.
The finder on this panel does the month count for any year-end.
Module 01 / 04
Activity-year rule
Module 02 / 04
Dated comparison
Module 03 / 04
Filing-year trap
Module 04 / 04
Worked timing
Tables and tools
Factor-year finder · ¶1.10
April 2026 to March 2027: 9 months in 2026, 3 in 2027.
Use the 2026 setMost of the activity falls in 2026, so the 2026 factors apply — published 11 June 2026.
The 2026 electricity factor is on a one-year data lag instead of two; say so in the methodology note if your comparative year used the 2025 set.
Rule: DESNZ 2026 Methodology Paper ¶1.10 and 2025 paper ¶1.8.
Nothing you choose is stored or sent.
Comparatives
The prior year, and whether to restate it
SECR puts last year’s figures beside this year’s, so the 2026 method change lands in every report that spans it.
Read the provisions and qualifications
The methodology paper leaves the choice to the reporter at ¶3.7: users “will need to decide whether they should adjust their previous years’ estimates to use the new conversion factors so that they have a consistent time series”, which it calls “a recommendation or requirement under some GHG reporting standards”.
If you restate, Appendix 2 of the paper gives a full electricity time series recalculated on the current method.
That appendix is a restated series and prints different numbers from Table 9 for the same data years, so it is never quoted as “the 2025 factor”.
If you do not restate, the methodology note says that the 2026 electricity factor was calculated on a one-year lag and that the comparative used the 2025 set.
A reader of the report should not have to guess why Scope 2 moved.
The SECR report template shows where that note sits, and the SECR reporting guide covers the comparatives rule.
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SECR comparison
Module 02 / 04
Reporter choice
Module 03 / 04
Restated series
Module 04 / 04
Two tables
Using the factors
Which worksheet feeds which scope
| Scope | Worksheets in the full set | Activity data you multiply |
|---|---|---|
| Scope 1 | Fuels; refrigerant and other; passenger and delivery vehicles you own or control | kWh of gas (gross CV by default), litres of diesel, kg of refrigerant topped up |
| Scope 2 | UK electricity; heat and steam | kWh of electricity, heat or steam bought |
| Scope 3 | Transmission and distribution; well-to-tank; business travel; freighting goods; waste; water; materials; hotel stay; homeworking | Passenger-km, tonne-km, tonnes of waste, nights, homeworking days |
SECR. Large unquoted companies report emissions from gas, transport fuel and electricity bought for their own use under Part 7A of Schedule 7; quoted companies report the wider list in Part 7.
The regulations name no factor set, and the government factors are the standard way to convert those figures; the SECR overview and the UK carbon reporting requirements cover who reports what.
UK SRS S2. UK SRS S2 ¶29(a)(ii) asks for measurement under the GHG Protocol Corporate Standard, ¶29(a)(v) asks for location-based Scope 2, and ¶B29 says the standard prescribes no factors but requires those that best represent the activity.
For UK electricity on the location-based method, the DESNZ generation factor is the obvious candidate; the UK SRS S2 reference covers the rest of the metrics.
Scope 3. The set covers travel, freight, waste, water and some materials, and runs out fastest for purchased goods, where supplier data or spend-based multipliers take over — the subject of the Scope 3 emissions page.
A tool that loads factors automatically should show which set produced each line; that is the first thing to test in GHG reporting software and carbon accounting software.
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Unquoted SECR
Module 02 / 04
Named methodology
Module 03 / 04
UK SRS method
Module 04 / 04
Location-based electricity
The files
Full set, flat file — and no condensed set
Until 2025 there were three spreadsheets, and the 2025 publication called the condensed one “recommended for most, and new, users”.
Read the provisions and qualifications
The 2026 methodology paper says at ¶¶2.3 and 3.3: “as of 2026, the Condensed set is no longer published”.
Nothing new replaces it; the full set takes its place and the 2026 page labels it “for all users”.
Every worksheet a condensed-set user relied on — fuels, fuel properties, conversions, UK electricity, transmission and distribution — is in the full set, which also carries well-to-tank and heat and steam.
DESNZ asks new users to read the workbook’s Introduction worksheet and regular users its “What’s new” worksheet.
A template built on the condensed layout needs re-mapping to the full set’s worksheet names before it takes 2026 data.
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Older files
Module 02 / 04
Condensed set ends
Module 03 / 04
Full set
Module 04 / 04
Worksheet coverage
Tables and tools
| File | What it is |
|---|---|
| Full set | Every factor for the year, with worksheet guidance; labelled “for all users” |
| Flat file | The same data in one table for software; republished July 2026 |
| Condensed set | Published to 2025; not published for 2026 |
| Methodology paper | How each factor is derived; Table 9 for electricity |
| Major changes report | Every factor that moved by more than 5% (Scope 1 and 2) or 10% (Scope 3) |
Gases and GWPs
Seven gases, and which GWPs
| Factor group | GWP basis in the 2026 set |
|---|---|
| Methane and nitrous oxide | AR5: CH4 = 28, N2O = 265 |
| Refrigerants and process gases | Almost all AR5; AR6 where no AR5 value exists |
| Well-to-tank bioenergy | Still AR4 |
| Hotel stays | AR4 or AR5, depending on the reporting hotels |
The GHG Protocol Corporate Standard covers the seven Kyoto gases: carbon dioxide, methane, nitrous oxide, hydrofluorocarbons, perfluorocarbons, sulphur hexafluoride and nitrogen trifluoride.
The 2004 text named six; nitrogen trifluoride was added by an amendment in February 2013, so the operative text is the base edition plus that amendment.
The UK factors give CO2, CH4 and N2O separately and as a CO2e total, using AR5 values because they are consistent with UNFCCC reporting and the UK inventory.
The paper adds that newer IPCC methods “have not yet been officially accepted for use under the UNFCCC”, so swapping AR6 values in for methane and nitrous oxide is wrong — while DESNZ itself used AR6 for refrigerants that had no AR5 value.
The GHG Protocol reference covers the standard and its revision.
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Seven gases
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2013 amendment
Module 03 / 04
AR5 equivalents
Module 04 / 04
UNFCCC basis
Pitfalls
Three mistakes, worked on one company
One company, 1,000,000 kWh of UK grid electricity in calendar 2026, revenue of £25 million, an intensity ratio per £100,000.
The correct location-based Scope 2 is 1,000,000 × 0.13096 = 130.96 tCO2e, or 0.524 tCO2e per £100,000.
| Mistake | What it reports | Error | The rule it breaks |
|---|---|---|---|
| Consumed factor used as Scope 2 | 143.96 tCO2e · 0.576 per £100k | +13.00 t (+9.9%), and the losses counted twice if Scope 3 also carries them | Methodology paper ¶¶3.1, 3.9 |
| 2025 factor applied to 2026 activity | 177.00 tCO2e · 0.708 per £100k | +46.04 t (+35.2%) | ¶1.10: match the activity year |
| Factor change reported as a reduction | Comparative 177.00 → 130.96, “−26%” | A fall with no change in use; 6–7 points of it method | Major changes report, row 17; ¶3.7 |
| 2026 factor applied to 2025 activity | Too low by 26.0% | −46.04 t against the correct 177.00 | ¶1.10 and the 2025 paper ¶1.8 |
The first mistake is the one that survives review, because 0.14396 is a real DESNZ number with a plausible label.
The second usually comes from a tool that picks the latest set on the day it runs.
The third is the one that ends up inside a progress claim: state the factor change, or restate the comparative, before any sentence about reductions.
One more number to keep apart: DESNZ’s fuel mix disclosure puts the CO2 intensity of UK generation in 2025 at 147 g/kWh — an operational, UK-generators-only figure, not the 0.13096 reporting factor.
And NESO’s Carbon Intensity forecast is a live half-hourly number for Great Britain, useful for shifting load and not for annual reporting.
Where things stand
The factor sets by date
The calendar is short and predictable: a set each June, used for that calendar year’s activity.
DESNZ’s statement of compliance with the statistics code says there is no set release date announced in advance, though the factors are regularly published in the first half of June.
The methodology paper names June 2027 for the next set.
Between sets, check the publication page’s update notes: the 2023 and 2026 sets were both corrected after release.
- 10 Jun 20252025 set published
Condensed, full and flat file; electricity on 2023 data.
- 11 Jun 20262026 set published
Full set and flat file only; electricity on 2025 data.
- Jul 2026Flat file republished
Zero values left blank; full set unchanged.
- 31 Dec 2026End of the 2026 activity year
Activity mostly in 2026 takes the 2026 set.
- Jun 20272027 set due
DESNZ gives the month, not the day.
Test yourself
Six factor claims, true or false
Each statement is one we see repeated about the government factors.
The false ones share a shape: a factor treated as a fact about performance, or a set chosen by publication date.
Each answer names the paragraph or row that settles it.
Conversion factors: true or false?
A company filing its 2026 accounts in March 2027 should use the 2027 factors, because they will be the latest.
The whole of the 26% fall in the electricity factor is a change of method.
The consumed electricity factor, 0.14396, is the right Scope 2 figure.
There is no condensed set for 2026.
The July 2026 correction changed the full set.
UK SRS S2 requires companies to use the DESNZ factors.
0 of 6 answered.
Nothing you choose is stored or sent.
Before you rely on it
A calculator gives a figure, not a verdict
Which factor applies can turn on facts a form cannot see: your boundary, your supplier contracts, your year-end and what changed since the last report.
Members can put their own figures to the member agent, which answers from the same sourced corpus as this page and says where it is unsure.
Or book a free 15-minute call to talk it through.
A reading and preparation sequence
ghg conversion factors: from the question to the evidence
- Step 0101
From activity to emissions
A conversion factor turns something you measured into something you report.Read the detail. - Step 0202
Comparability
Why the factor fell Read the detail. - Step 0303
Choose the factor year
The rule is one sentence of the 2026 methodology paper, at ¶1.10: “The 2026 GHG Conversion Factors are for use with activity data that falls entirely or mostly within 2026.”Read the detail. - Step 0404
Comparative figures
SECR puts last year’s figures beside this year’s, so the 2026 method change lands in every report that spans it.Read the detail. - Step 0505
Reporting application
SECR.Large unquoted companies report emissions from gas, transport fuel and electricity bought for their own use under Part 7A of Schedule 7; quoted companies report the wider list in Part 7.Read the detail. - Step 0606
Choose the workbook
Until 2025 there were three spreadsheets, and the 2025 publicationcalled the condensed one “recommended for most, and new, users”.Read the detail. - Step 0707
Greenhouse gases
The GHG Protocol Corporate Standardcovers the seven Kyoto gases: carbon dioxide, methane, nitrous oxide, hydrofluorocarbons, perfluorocarbons, sulphur hexafluoride and nitrogen trifluoride.Read the detail.
Dates, with their status
The relevant dates, drawn in order
- Activity in 202601
Choose by activity year
The 2026 factor set is intended for activity data falling entirely or mostly within 2026, rather than a report filed during that year. - 11 June 202602
Full set published
The annual factor set and methodology are published. Read the introduction and relevant worksheet guidance before using a factor. - 31 July 202603
Flat file corrected
Unavailable factors had been recorded as zero. The corrected flat file restores blanks; the full-set workbook already had the correct blanks. - June 2027 · planned04
Next annual publication
The 2026 methodology identifies June 2027 for the next publication. Check the owner before using a later-year set.
Continue your research
Related reporting guides, one question at a time
Frequently asked
GHG conversion factors, answered
What are the UK government GHG conversion factors for company reporting?
They are the annual emission factors the Department for Energy Security and Net Zero publishes so that organisations can turn activity data — litres of fuel, kWh of electricity, kilometres travelled, tonnes of waste — into kilograms of carbon dioxide equivalent for Scope 1, 2 and 3.
Many people still call them the Defra or BEIS factors after the departments that published them earlier.
What changed in the 2026 GHG conversion factors?
The UK electricity factor fell 26% and the transmission and distribution factor 30% against the 2025 set.
DESNZ attributes most of the electricity fall to grid decarbonisation and 6 to 7 percentage points to methodological changes, because the factor now lags its publication year by one year instead of two.
The condensed spreadsheet is no longer published.
What is the 2026 UK electricity conversion factor?
For electricity generated, including imports, it is 0.13096 kgCO2e per kWh, on 2025 data, from Table 9 of the 2026 methodology paper.
Grid losses are a separate 0.01299, and the combined consumed figure is 0.14396.
The generated factor is the Scope 2 figure; the losses go in Scope 3.
Which year of conversion factors should I use?
The year your activity data falls in, entirely or mostly — not the year you publish.
The 2026 methodology paper says the 2026 factors are for use with activity data that falls entirely or mostly within 2026.
A company reporting a 2026 financial year in spring 2027 still uses the 2026 set.
Is there a condensed set of conversion factors for 2026?
No. The 2026 methodology paper says that as of 2026 the condensed set is no longer published.
The release offers a full set labelled for all users and a flat file for automatic processing, and every worksheet a condensed-set user relied on is in the full set.
Why does the consumed factor show as 0.14396 in one place and 0.14395 in another?
They are the same figure rounded two ways.
Table 9 of the methodology paper prints 0.14396, adding unrounded components.
Adding the two five-decimal factors in the workbook — 0.13096 and 0.01299 — gives 0.14395.
Quote 0.14396 as DESNZ’s consumed factor, and neither belongs in Scope 2 on its own.
What are the 7 GHGs?
Carbon dioxide, methane, nitrous oxide, hydrofluorocarbons, perfluorocarbons, sulphur hexafluoride and nitrogen trifluoride.
The 2004 GHG Protocol Corporate Standard named six; nitrogen trifluoride was added by an amendment in February 2013.
Which global warming potentials do the UK factors use?
IPCC Fifth Assessment Report values for methane (28) and nitrous oxide (265).
The methodology paper names exceptions: refrigerants use AR6 values where no AR5 value exists, well-to-tank bioenergy is still on AR4, and hotel-stay factors mix AR4 and AR5.
When will the 2027 conversion factors be published?
The 2026 methodology paper says the next publication is due in June 2027.
Recent sets appeared on 10 June 2025 and 11 June 2026.
The 2027 set will be for activity in 2027 and will not replace the 2026 set for activity in 2026.
Can I use the UK factors for overseas sites?
Not the UK electricity factor: electricity used abroad takes the grid factor of the country where it is consumed.
The 2026 methodology paper has a section on overseas electricity factors, and DESNZ’s landing page says the factors may be used for other purposes at the user’s own risk.
Are the conversion factors the same as the live grid carbon intensity?
No. NESO’s Carbon Intensity service forecasts Great Britain’s grid intensity half-hour by half-hour, which is useful for timing demand.
The annual DESNZ factor is the figure reporting frameworks expect, and it includes imports and a CO2e basis the live figure does not.
Sources
Primary sources
Every figure, date and status on this page traces to the instrument’s owner.
Secondary commentary is never the source for a number.
- DESNZ (GOV.UK)Greenhouse gas reporting: conversion factors 2026
Published 11 June 2026; the July 2026 flat-file correction and what it touched; the file labels.
- DESNZ2026 conversion factors methodology paper — ¶¶1.6, 1.9, 1.10, 1.13, 2.3, 3.1, 3.3, 3.7–3.9 and Table 9
The activity-year rule, the electricity factors, the end of the condensed set, the scope split and the restatement choice.
- DESNZ2026 conversion factors: major changes report, rows 17–19 and 39
Electricity −26%, losses −30%, the attribution between grid mix and method, and the 5% / 10% “major change” thresholds.
- DESNZConversion factors 2026: full set (for all users), XLSX
The workbook that replaces the condensed set for most users.
- DESNZ (GOV.UK)UK government conversion factors for company reporting (collection)
The index of every set; it does not say which year is current.
- DESNZ (GOV.UK)Greenhouse gas reporting: conversion factors 2025
Published 10 June 2025, with the condensed, full and flat-file sets.
- DESNZ2025 conversion factors methodology paper, Table 9
The 2025 set’s electricity factors on 2023 data.
- DESNZFuel Mix Disclosure data table 2026
The residual mix and the 147 g/kWh generation intensity — operational figures, not reporting factors.
- GOV.UK (DESNZ, Defra, BEIS)Environmental Reporting Guidelines, including SECR requirements
The SECR guidance the factors are written for.
- legislation.gov.ukSI 2008/410 Schedule 7 Part 7A (unquoted energy and carbon report)
Gas, transport fuel and purchased electricity — the figures the factors convert.
- Department for Business and TradeUK SRS S2 Climate-related Disclosures, ¶¶29(a)(ii), 29(a)(v) and B29
GHG Protocol measurement, location-based Scope 2, and no prescribed factors.
- GHG ProtocolCorporate Accounting and Reporting Standard
The seven gases, NF3 added by the 2013 amendment.
- Defra (GOV.UK)UK’s carbon footprint — spend-based emissions multipliers
The separate spend-based product the methodology paper points to at ¶1.6.
- NESOCarbon Intensity API
Live half-hourly GB grid intensity — not the annual reporting factor.