What is my organisation's carbon footprint?

Most carbon calculators open with an empty form, which is why most people close them again. This one opens with an answer: the published average footprint for a UK organisation of a given sector and size, starting with a fourteen-person professional, scientific or technical firm, split into the eight things that make it up. Every one of those lines is somebody else's number, and every one is marked as an estimate. As you find a real figure, for example the gas you actually burned last year, it replaces that line, the borrowed average drops out of the total, and the marker disappears. The footprint becomes measured rather than assumed one line at a time, and you can see exactly how much of it still is not yours.

An average you can correct is more use than an empty box you abandon. It also shows you the shape of a footprint before you spend a morning collecting data for the smallest line on it.

It shows the average and explains every line of it, and that is all it does. The sector and employees fields at the top can be changed, but every figure is still the one for fourteen people in section M. The line fields arrive one at a time, starting with the things you buy, because that line is 86% of the total. Saving your entries to a file and loading them back arrives with the fields, since there is nothing to save until then.

No. There is no sign-up, no account and no email gate on the result. Nothing leaves your browser. There is no server to send it to, and when the line fields arrive, the file you download will be the only copy in existence.

You can use it to see where you stand. It is an estimate, and mostly an estimate of somebody else. It is not a verified footprint, not an audited one, and not comparable with either. It does not produce a compliant Streamlined Energy and Carbon Reporting disclosure. Do not submit it as a Carbon Reduction Plan under PPN 006, which needs your own data for scopes 1 and 2 and a director's signature. If you need a figure that survives an auditor or a procurement officer, this page is where you start, not where you finish.

Every line starts from the same two figures, the sector and the headcount. The sector is M, professional, scientific and technical activities, the first one built. Fourteen people is the average for a UK business with 10 to 19 employees, being 1,952,000 people in 142,500 businesses at the start of 2025 [8]. The figure per square metre uses 210 m²: 15 m² of gross floor space per person, from 12 m² of usable office space per full-time employee for professional services, with gross space taken as 20% higher than usable space, the upper end of the 15 to 20% the same guide gives for offices [9]. No line uses floor area.

Ashgrove Advice is an invented consultancy of fourteen people, in section M of the industry classification: professional, scientific and technical activities. It has entered nothing yet, so every line is the published average for its sector, worked out from its headcount.

None of Ashgrove's total is its own yet. When the purchases field opens, the £596,400 is replaced by the year's total from its own purchase ledger, and that line loses its marker. Things you buy is 86% of the total, which is why the purchase ledger matters more than any meter.

Spend is what section M businesses buy per job, from the ONS supply and use tables for 2023, which record what each industry buys from every other, product by product. Energy, water, waste, transport and hotels are taken out, because other lines count them. Rent and agency staff stay in, because no other line does. That leaves £42,600 per job, and fourteen people buy £596,400.

Each product bought is converted at Defra's multiplier for that product, and the results are added up. The largest purchases are architectural and engineering services, 12.4% of spend at 0.162 kgCO2e per pound; management consulting, 10.7% at 0.081; other professional services, 8.7% at 0.126; and computer services, 5.8% at 0.100. Across all 64 products bought, the average is 0.18216 kgCO2e per pound, and £596,400 × 0.18216 is 108,640 kgCO2e.

Defra also publishes a single multiplier for each industry section, 0.703 for section M. That figure describes the products the section sells, and it is higher than every product multiplier within the section, so the page does not use it.

Defra publishes the multipliers for exactly this use where an organisation has no activity data of its own, and says activity data should be preferred where it exists. Both the multipliers and the purchases are in 2023 prices. The purchases include VAT the buyer cannot reclaim, which the multipliers leave out, so the line runs slightly high. The job count includes the self-employed, who buy less, so the spend per employee of a business with staff is probably higher. [1]

The UK environmental accounts record the fuel each industry burns, by source. In 2024, professional, scientific and technical businesses burned 19.4 petajoules of fuel on their own premises, 94% of it natural gas and the rest oil. Divided by the section's 3.48 million jobs, that is 1,546 kWh per job, and fourteen people use 21,644 kWh. At 0.18231 kgCO2e per kWh, DESNZ 2026, gross calorific value, that gives 3,946 kgCO2e.

The whole figure is converted at the gas factor, which slightly understates the oil. Fuel burned in road vehicles, a further 4.2 petajoules, is not counted here, because the business travel line covers travel. The job count includes part-time jobs and the self-employed. [2]

The same accounts record all the energy each industry uses at the point of use: 41.0 petajoules for section M in 2024. Taking away the 23.7 petajoules of fossil fuel, on site and in vehicles, leaves 17.3, mostly the electricity the section bought. ONS does not publish electricity as a line of its own, so this figure is worked out by subtraction. Divided by 3.48 million jobs, it is 1,376 kWh per job, and fourteen people use 19,264 kWh. At 0.13096 kgCO2e per kWh, DESNZ 2026, grid average, that gives 2,523 kgCO2e.

DESNZ puts the electricity lost in transmission and distribution at 9.0% of what is sent into the grid, from DUKES Table 5.1.2, which adds 0.01299 kgCO2e for every kWh used, 250 kgCO2e, reported as scope 3 category 3 because the loss happens on the grid. Why the 2026 figure is lower than last year's is set out under Why does electricity look lower than last year? [3]

For fourteen people in professional, scientific and technical services, this calculator uses the national accounts figures per job: 19,264 kWh of electricity and 21,644 kWh of fuel a year. Two building benchmarks give the figures below for 210 m² of office. The 2008 office benchmark puts electricity within 4% of the calculator's figure, and both benchmarks put fuel higher.

CIBSE TM46: 2008 gives typical energy per m² for each type of building and is the basis of every Display Energy Certificate in England, Wales and Northern Ireland. [11] ND-NEED, the Non-domestic National Energy Efficiency Data-Framework, matches metered gas and electricity to buildings and divides by floor area. Its figures are medians, so half of offices use more. [10]

The calculator's figures cover the whole of section M, which includes laboratories and vets as well as offices, while both benchmarks describe office buildings. Every row uses the conversion factors the calculator uses, DESNZ 2026: 0.13096 kgCO2e per kWh of electricity and 0.18231 per kWh of gas. This comparison is recalculated whenever the calculator changes how it works out gas or electricity. [2] [3]

National Travel Survey 2025, table NTS0412b, England, 2,064 miles per employed person a year, split by mode and converted mode by mode at the DESNZ 2026 factors, giving 396 kgCO2e per person a year. Homeworking adds 184 kgCO2e per person a year, at 0.32393 kgCO2e per full-time-equivalent hour worked at home, DESNZ 2026. No one publishes the hours, so the page assumes 28% of a 253-day, eight-hour working year, taking the ONS hybrid-working share for January to March 2025 as a share of time worked. The commuting figure needs no adjustment for it, because the travel survey already counted the journeys people actually made. Together the line is 580 kgCO2e per person a year, and fourteen people make 8,120 kgCO2e. [4]

National Travel Survey 2025, table NTS0409b, England, 376 miles per resident a year for business, scaled to 753 miles per employed person on the ratio the same survey gives for commuting, and converted by mode to 146 kgCO2e. The survey does not cover air travel, so there are no flights in that figure at all. Fourteen people make 2,044 kgCO2e. [5]

England produced 22.7 million tonnes of commercial waste in 2024, and the service industries had 26.8 million jobs, which is 0.85 tonnes per job. That counts retail, hospitality and wholesale too, so it is several times what an office throws away, and the line is high. Fourteen people make 11.9 tonnes.

The DESNZ 2026 factor for commercial and industrial waste is 520.58 kgCO2e per tonne sent to landfill and 4.65 per tonne burned or recycled. No split of commercial waste by where it goes is published, so the page uses the split for all waste in England in 2024, 21.1% to landfill. That figure includes construction waste. The blended factor is 113.5 kgCO2e per tonne, and 11.9 tonnes make 1,351 kgCO2e. [6]

CIRIA C657, Waggett and Arotsky, 2006, typical office use 4.0 m³ per employee a year, converted at 0.1913 supply plus 0.17088 treatment, giving 1.45 kgCO2e per person a year. Fourteen people make 20 kgCO2e. The benchmark is older than TM46. [7]

Things you buy, scope 3 category 1, is 86% of the average. The carbon in those purchases was produced by the suppliers, which is why an office with a small gas bill still has a large footprint. How the spend and its carbon per pound are found is set out under Things you buy.

Two separate things go into every line, and the page names both. The activity data, being the kWh, miles, tonnes or pounds spent, comes from a published average until you replace it. The conversion factor that turns activity into carbon comes from the UK government greenhouse gas conversion factors for company reporting, the 2026 set, published in June 2026 and reissued in July, last checked here on 27 September 2026 and next reviewed in June 2027. They are Crown copyright under the Open Government Licence, which is to say nobody owns them and anybody may use them, including you. The set changes once a year, published each June, and every figure on this page is recalculated when a new set arrives.

The 2026 grid electricity factor is 0.13096 kgCO2e per kWh, 26% lower than the year before. Most of that is the grid genuinely getting cleaner, worth 16 of those 26 points over 2023 and 2024. The department also cut the lag between the data and the publication year from two years to one, so this single update absorbs two years of change at once, worth another 3 points, and the last 6 or 7 are changes to how the figure is compiled, including a correction for double counting. If you compare this year's footprint with last year's and see a fall in electricity, some of it happened in a spreadsheet rather than in your building. State which factor year you used, every time.

Per unit of energy, yes, and by about 39% on the 2026 factors. That is a recent reversal. It also means a building that swaps a gas boiler for a heat pump gains twice: a lower factor and, because a heat pump moves heat rather than making it, fewer units.

A total on its own cannot be compared with anything, because a larger organisation has a larger one and that tells you nothing about either. So the same footprint is given four ways. Per organisation is the headline, 127 tonnes for the fourteen-person firm above. Per employee, 9.1 tonnes, and per square metre of floor space, 604 kg on 210 m², let two organisations be set against each other. The fourth is per item you sell or service you deliver, which is carbon labelling, meaning a carbon figure attached to one product or service rather than to the organisation as a whole. That is the only one of the four your own customers can use, because it is the only one that compares the thing they are actually buying.

There are several free carbon calculators for UK small businesses, and they are worth knowing about before you spend an afternoon in one. Every one of them opens with an empty form and gives you a number at the end. Checked 16 September 2026.

What this page does differently is start with an answer rather than a blank form, and then tell you how much of that answer is yours. Every line says whether the figure is your own or borrowed from a published average, names the source it was borrowed from, and states which year of government factors converted it. Nothing is stored, nothing is asked for, and there is no account. The catch is the other side of the same coin: until you have entered anything, this is a description of an organisation like yours rather than a measurement of your own, and the tools above will get you to a measured figure sooner.