Business carbon footprint calculator

Carbon calculations are strongest when they begin with something that actually happened.

That might be:

• 26,000 kWh of electricity;
• 8,400 kWh of natural gas;
• 12,000 litres of diesel;
• 18 return flights;
• 4 tonnes of mixed commercial waste.

The underlying calculation is straightforward:

Activity data × greenhouse gas conversion factor = greenhouse gas emissions

If your business used a known quantity of natural gas, that quantity is multiplied by the Government factor applying to that fuel and reporting period.

The same principle applies across electricity, transport, waste, water and the other sources covered by the calculator.

The multiplication is the easy part. Deciding what belongs inside the footprint, which factor applies and whether an estimate is being presented as measured data is where carbon accounting becomes more serious.

We use published UK Government factors rather than inventing our own averages.

A business footprint is not necessarily just carbon dioxide.

Business activities can produce carbon dioxide, methane, nitrous oxide and fluorinated gases, amongst others. Different greenhouse gases warm the atmosphere by different amounts.

Carbon dioxide equivalent, written CO₂e, converts their climate effect into a common unit.

That is why your result is given in tonnes of CO₂e, rather than simply tonnes of CO₂.

We treat these differently.

Measured data starts with an actual figure such as a meter reading, bill, fuel invoice or recorded mileage.

Estimated data uses another known quantity, such as floor area, and a documented estimation method.

Unquantified means the source may exist, but you have not supplied enough information to calculate it.

I would rather show a business five measured categories and two labelled gaps than produce a beautifully precise total by pretending those gaps do not exist.

Scope 1 covers greenhouse gas emissions from sources your organisation owns or controls.

For many smaller businesses these include:

• gas burned in a boiler;
• petrol or diesel used in company-owned vehicles;
• other fuels burned on site;
• refrigerant gases released from air-conditioning or refrigeration equipment.

A professional services company might have very little Scope 1. A manufacturer, logistics company or business operating a large vehicle fleet can have a great deal.

Scope 2 covers emissions associated with generating purchased electricity, steam, heating or cooling consumed by your organisation. This calculator uses the location-based method, meaning the average for the UK grid.

For most UK SMEs, purchased electricity is the principal Scope 2 source.

The electricity arrives without a chimney attached to it, but electricity generation still has an associated greenhouse gas footprint. The UK Government publishes conversion factors allowing electricity consumption in kWh to be translated into CO₂e.

Scope 3 includes indirect emissions which are not included in Scope 2.

That makes it considerably broader.

For an office-based company, flights and commuting might be important Scope 3 sources. For a retailer or manufacturer, purchased products, raw materials, freight and the use of sold products may dwarf office energy.

This calculator does not claim to measure all 15 Scope 3 categories for every type of company.

It measures a defined group of common business activities and tells you when something has not been quantified.

If you need a complete corporate greenhouse gas inventory, that requires a broader assessment of your organisation and value chain.

The GHG Protocol Corporate Value Chain Standard divides Scope 3 into 15 upstream and downstream categories.

Not every category will be material for every business, but a serious Scope 3 assessment should consider which ones apply before excluding them.

The purpose of this table is not to make a ten-minute calculator look like a complete Scope 3 inventory. It is to make the boundary visible.

A 72-tonne result covering eight known sources is a calculation of those eight sources. It should not quietly turn into the claim that “our entire company emits 72 tonnes”.

Before collecting numbers, establish which parts of the organisation belong inside the footprint.

For a straightforward single-company SME, that may be obvious.

Groups, subsidiaries, joint ventures, leased operations and shared ownership can make it less so.

The GHG Protocol provides approaches based on equity share, financial control and operational control.

The important thing is consistency. You need to know which operations belong inside the footprint before deciding which emissions to collect.

Most organisations calculate a footprint over a 12-month period.

Keeping the same reporting basis from year to year makes progress easier to track.

For most businesses this means starting with direct fuels, company-controlled vehicles, refrigerants and purchased energy.

These are usually the easiest emissions to establish from bills and operating records.

This takes more thought.

The GHG Protocol identifies 15 Scope 3 categories. Not every category will be significant for every company, but a serious footprint should consider which ones apply before excluding them.

Use actual quantities where possible.

Useful records include:

• electricity bills;
• gas bills;
• fuel records;
• mileage;
• travel booking data;
• waste reports;
• refrigerant servicing records;
• procurement information.

Good carbon accounting becomes much easier when ordinary business records are kept well.

Multiply the activity by the relevant factor, preserving the correct units and reporting basis.

A footprint should tell you where estimation was necessary and what was left outside the boundary.

Your second footprint can be more valuable than your first.

Once the process is repeatable, you can see whether a reduction is real rather than simply the consequence of changing the calculation.

Start with the largest sources.

If gas dominates, investigate heating and building efficiency.

If company vehicles dominate, look at mileage, vehicle choice, routing and electrification.

Where the same journey could be made by rail, the size of the saving depends on the car it replaces. How train and car emissions compare sets out the 2026 figures for petrol, diesel, hybrid and electric cars.

If freight dominates, look at load consolidation, routing, and whether anything moving by air or road could move by sea or rail.

If purchased goods dominate a more complete Scope 3 inventory, the work moves into procurement and suppliers.

A carbon credit does not reduce your company’s Scope 1, Scope 2 or Scope 3 inventory.

If you cut gas consumption, drive fewer fossil-fuel miles or buy less carbon-intensive material, you can reduce the underlying footprint.

We keep reduction work separate from funding climate projects because they are different things.

The Unquantified list gives you a ready-made job list for the next calculation.

You do not need perfect data before starting.

But you should know which data are imperfect.

Use a consistent boundary and methodology and the calculator becomes a way to track what is changing year by year.

The Greenhouse Gas Protocol Corporate Standard is one of the principal frameworks used for corporate greenhouse gas accounting.

It defines corporate inventories around organisational boundaries and Scope 1, Scope 2 and Scope 3 emissions.

If you are building a formal GHG inventory rather than taking a first measurement, the boundary matters as much as the multiplication.

Streamlined Energy and Carbon Reporting, usually shortened to SECR, requires qualifying UK organisations to disclose specified energy and carbon information.

The Government’s company reporting conversion factors are relevant to SECR calculations.

A free online calculator is not, by itself, an SECR reporting process.

Certain suppliers bidding for major UK central government contracts may need a Carbon Reduction Plan under current procurement policy.

A Carbon Reduction Plan has defined reporting requirements and should not be confused with downloading an informal calculator result.

Read our guide to Carbon Reduction Plans and PPN 006 →

A business carbon footprint is the greenhouse gas emissions associated with an organisation’s activities over a defined period.

These can include direct emissions from fuels and vehicles, emissions from purchased electricity and indirect emissions associated with travel, waste, suppliers and the wider value chain.

Footprints are normally expressed in tonnes of carbon dioxide equivalent, or tCO₂e.

Yes. “Business carbon calculator”, “company carbon footprint calculator” and “business carbon footprint calculator” are different ways of describing the same basic task: calculating greenhouse gas emissions associated with an organisation.

The important distinction is not the name of the calculator. It is what sources the calculation actually includes.

Scope 1 covers direct greenhouse gas emissions from sources your organisation owns or controls.

Examples include fuel burned in company boilers, fuel used in company-owned vehicles and refrigerant leakage from equipment under the organisation’s control.

Scope 2 covers indirect emissions from purchased or acquired electricity, steam, heating and cooling consumed by the organisation.

For many UK businesses, purchased electricity is the principal Scope 2 source.

Scope 3 covers other indirect emissions occurring across the organisation’s value chain.

The GHG Protocol divides Scope 3 into 15 categories including purchased goods and services, capital goods, transport, waste, business travel, employee commuting, leased assets and the use of sold products.

This calculator covers selected common Scope 3 sources rather than claiming to calculate every category for every business.

If you simply want an initial operational footprint, starting with the significant sources for which you have data is reasonable.

If you are producing a fuller greenhouse gas inventory, you should consider which Scope 3 categories are relevant to the organisation rather than assuming they can all be ignored because the company is small.

It means the emissions source exists or may exist, but you did not provide enough information for us to calculate it.

We do not treat missing data as zero.

Your result lists the Unquantified sources so you know exactly where the gaps are.

Measured emissions start with actual activity data, such as electricity consumed in kWh or litres of fuel purchased.

Estimated emissions start with another piece of information, such as building floor area, and use a documented method to estimate the activity.

Both can be useful. We label them differently.

The calculator uses UK Government greenhouse gas conversion factors for company reporting.

These are published annually by the Department for Energy Security and Net Zero and allow organisations to calculate emissions from activity such as fuel consumption, electricity use and travel.

Business activities can release several different greenhouse gases.

CO₂e, or carbon dioxide equivalent, expresses their climate effect in a common unit so they can be included in a single greenhouse gas footprint.

Purchased electricity consumed by your organisation is normally Scope 2.

Direct emissions from fuels burned in equipment your organisation owns or controls are generally Scope 1.

Business travel in vehicles not owned or controlled by the reporting company is generally accounted for within Scope 3.

Different arrangements can affect classification, which is one reason formal carbon inventories need clearly defined boundaries.

Fuel combustion from vehicles owned or controlled by the organisation is generally Scope 1.

Travel in vehicles outside your ownership or control may fall elsewhere, including Scope 3.

Yes. Employee commuting is one of the GHG Protocol’s 15 Scope 3 categories.

Homeworking can create indirect emissions associated with energy employees use while working remotely.

Whether and how they are quantified depends on the reporting methodology and boundary being used. This calculator includes homeworking, reported under Category 7 (employee commuting).

The calculator can help you establish activity-based emissions and identify data gaps, but it is not presented as a substitute for your organisation’s own SECR assessment or disclosure process.

If you need a footprint for formal reporting, we can review the boundary, inputs and methodology with you.

Treat the calculator as a starting point rather than assuming its output satisfies a particular procurement requirement.

A Carbon Reduction Plan has specific requirements about the emissions and commitments reported.

Annual calculation is usually the most useful starting point because it allows the business to compare consecutive reporting periods.

Use a consistent boundary and methodology where possible. Otherwise a change in the number may reflect a change in accounting rather than a real change in emissions.

No.

Your company’s calculated Scope 1, Scope 2 and Scope 3 emissions remain the same.

Funding climate projects is a separate action from reducing your own greenhouse gas emissions, and the calculator displays it separately.

Because internal emissions reduction and financing climate action elsewhere can both be useful.

They are not interchangeable.

We would rather state that plainly than subtract a payment from your footprint and produce a cleaner-looking number.

Your browser first calculates a preview.

When you proceed to payment, your underlying answers are sent to the server and the footprint and funding amount are calculated again. The server then requests the Stripe payment.

The amount actually paid is checked before the transaction is recorded.

The initial footprint preview is calculated in your browser.

If you choose to fund a project, the inputs needed to recalculate your footprint and payment are sent to the server.

Nothing you enter is stored by us, and you are not asked for an email address to see your result. The one exception is funding a project: your answers are then sent to our server, which works the footprint out again and prices it, because an amount to be charged cannot be trusted to a figure produced in a browser. Card details go to Stripe and never reach C Level. When you pay, we keep a record of the payment: your email address, your organisation, the tonnes and the amount.

No. The calculator gives you your footprint and a downloadable report showing every calculation line and its Government factor reference. If you fund a project, you also receive a payment receipt.

The current rate is £26.25 per tonne of CO₂e plus VAT.

The contribution, VAT and total payment are shown before you pay.

Our Carbon Footprint Consultancy can extend the calculation beyond the sources covered here, resolve data gaps, assess relevant Scope 3 categories and establish a repeatable reporting process.

Talk to us about Carbon Footprint Consultancy →