Carbon footprint calculator for UK businesses

To make it easier to measure and compare carbon footprints, all emissions are converted into carbon dioxide equivalent (CO2e).

CO2e allows for a number of greenhouse gases to be expressed as a single number. So, while CO2 only accounts for carbon dioxide, CO2e accounts for carbon dioxide plus all the other greenhouse gases.

CO2e is made up of serval greenhouse gases, the most common are:

• Carbon dioxide (CO2) makes up around 80% of all greenhouse gas (GHG) emissions. That’s because it’s generated from burning fossil fuels and the manufacture of cement, so it’s used in lots of industries and in large-scale activities.
• Methane (CH4) is generated by livestock, as well as other farming activities and landfill decay. Methane makes up around 10% of the GHGs, but it’s much more harmful than CO2.
• Nitrous oxide (N2O), sometimes known as laughing gas, is generated through various agricultural activities, fossil fuel combustion and water treatment processes. N2O makes up around 7% of the GHGs.
• Fluorinated gases are man-made gas gases caused by a number of industrial processes they only make up around 3% of emissions.

These are the direct emissions produced by your business activities, or the activities under your control. For example, on-site gas boilers, fleet vehicles and air-conditioning leaks.

The most common Scope 1 emissions include:

• Gas supply emissions are usually produced by heating, but they can come from a company kitchen, too. They’re classed as scope 1 emissions because you pipe gas into the building and combust it in the on-site boiler, with CO2 being released from your premises.
• Company vehicles create Scope 1 emissions because the fuel is burnt in those vehicles and the emissions come directly from the exhausts of those vehicles.
• Air-conditioning units in your business premises can produce harmful emissions when the coolant leaks or needs topped up.

These are the indirect emissions caused by the electricity purchased and consumed by your organisation (it includes steam, heat and cooling). These emissions are created during the production of the energy and are the easiest ones to understand and measure.

Scope 2 emissions include:

• Purchase of electricity for own use
• Purchase of heat for own use
• Purchase of cooling steam for own use

These are the indirect emissions (not included in Scope 2) that occur in during your business activities and processes. They are basically everything else that your company does that can have an impact on the environment (that’s not covered in Scope 1 and 2).

Scope 3 emissions categories include:

• Purchased goods and services
• Business travel
• Employees commuting
• Waste disposal
• Use of sold products
• Transportation and distribution
• Investments
• Leased assets and franchises

Many businesses (especially those who don’t produce and sell physical products), will find that most of their Scope 3 emissions come from the top three activities listed above; the goods and services you use to get business done, and the commuting and in-work travel by your staff.

The calculator is created using 2020 BEIS carbon emissions data; therefore you will need to use 2020 company data for this task.

First, you’ll need your premise’s energy bill to see how much your total charge was, and how much electricity you used in kWh (Kilowatts per Hour). You’ll also need any other energy bills, such as gas, if your business uses this.

Then, you’ll collect information about your how your staff commute to work and their heating habits if they work from home. To help you gather this information, we’ve created a free and easy-to-use questionnaire which you can download here.

You'll also need:

• Company travel information (in-work, company paid travel)
• F-gas certificate
• Number of employees

The two most important tabs in the calculator are ‘Company Settings’ and ‘Carbon Footprint’.

• Tab 1. ‘Company Settings’ – This is where you input all the relevant information about your company.

• Tab 2. ’Carbon Footprint‘ – This tab that will show you what the carbon footprint of your company is, broken down across all the different areas of Scope 1, 2 and 3 emissions.

Setting the number of staff in your organisation

First, enter the total number of staff for your company. Things to remember:

• This is the average headcount across the 12-month period you are measuring, not the total/fluctuating number of people you’ve employed over the year.
• You can include part-time staff. Remember, it’s just an average headcount so it doesn’t have to be highly precise. And it’s fine to use fractions here, for example 15.5 would be a perfectly valid number for your average headcount.
• You don’t have to include freelancers or contractors here. You can include them here if you tend to treat them the same as permanent members of staff. Alternatively, you can exclude them at this point and instead include them later as a scope 3 emission (under the purchase of goods and services).
• Setting the number of staff will help the model to calculate your company’s commuting emissions and homeworker emissions (e.g. gas and electricity usage from working at home).

A note on multiple offices

If your company has multiple offices in the same country, then you have two choices:

1. Combine all the data into this one model
2. Pick one office and model that.

Setting the reporting periods

Always leave this at 12 months because you’re looking at your annual footprint.

Setting the working days in the year

This is an average number of working days in a year across all your staff, it doesn’t need to be highly accurate. The default is 232 days. That’s based on 52 weeks, minus 4 weeks holiday (the UK minimum amount) minus a further 8 days for the UK bank holidays.

Setting the percentage of time that people work from home

The next box down allows you to set the percentage of time that people work from home.

The first box in the ‘Scope 1’ section of the model is a drop down where you can pick a ‘Simple’ or an ‘Advanced’ mode for specifying your gas usage if you have multiple offices. We would advise using ‘Simple’ mode here. The difference between the two is:

1. Simple – Enter the amount you spend on gas and the cost per kWh. You’ll find those on your gas bill or you could ask your landlord. From those two numbers, the calculator can work out your emissions.
2. Advanced – This is only for businesses that have several office premises

Using the ‘Advanced’ setting

If you have multiple offices within the UK, you can use the ‘Advanced’ option and ‘Gas and Electricity (Advanced) tab’. In this tab, you can input the monthly energy and gas consumption in kWh per office location.

Calculating additional Scope 1 emissions

A common emission here is any refrigerant leaks from office aircon systems. Your air-con emissions value can usually be found on an ’F-Gas certificate‘, which is provided by the company who service your system.

This is the simplest of the three scopes because it’s your indirect emissions from the purchase of electricity. (It’s ‘indirect‘ because you’re not actually burning the fossil fuels.) The calculator uses a simplified method, where you enter the amount of money you spent on electricity in that year and the price that you pay (pence per kWh). When you open the carbon footprint calculator, you’ll see three boxes that you need to complete for your Scope 2 emissions:

• Annual offices electricity bill (£)
• Percentage of premises on 100% renewable energy
• The cost per kWh of electricity
• The amount you spent on electricity over the 12-month period

If you know that your premise is already supplied by a 100% renewable energy provider, you could set the ‘% of offices on 100% renewable energy’ box to 100% (which would reduce your Scope 2 emissions to zero).

You can calculate the homeworkers emissions by surveying your staff using the free template we have created.

• Average percentage of time spent working from home – If this is set to 0% (everyone comes into the premises every day), your homeworker emissions will be zero.
• The percentage of homeworkers who have 100% renewable energy - You won’t know this to begin with, so we recommend leaving it at 0% to give you an initial idea of how your homeworker emissions compare to your overall emissions.
• Percentage of time that homeworkers run their heating across the reporting period. This would be how often the heating is run across the time period you are reporting on. For example, across a 12-month period we would suggest this is set to 50% (heating run from October to March inclusive). If you are running a report for a 3-month period over the winter you might want to increase this to 100%.
• Percentage of time during the day that a homeworker will have the heating on.
• Percentage of time that homeworkers run their air conditioning during the reporting period. This would be how often the air conditioning is run across the time period you are reporting on.
• Percentage of time during the day that a homeworker will have the air conditioning on. For example, during a period when the air conditioning is on (see number 5) what % of the working day is the air conditioning is on for.

Complete this section with the data gathered from all your staff. We’ve created a free, easy-to-use staff survey template that you can download here.

Staff commuting emissions are based on average commuting distances across different vehicle types (cars, trains, buses, etc.).

Once you have inputted all the relevant data to the ‘Company Settings’ tab, open the ‘Carbon Footprint’ tab to see your company’s total carbon footprint at the bottom (highlighted in blue).

The ‘Trees required to offset’ is the number of trees you’d need to plant to offset your business’s entire carbon footprint.

This calculation is included as a simple way to understand your carbon footprint and its impact. SSE Energy Solutions strongly recommend focussing on reducing your company's overall carbon emission outputs. There are many carbon offsetting solutions which, in accordance with reducing your overall carbon emissions outputs, will set you on your way to a net zero future.

Share it!

We’ve created a free carbon emissions reporting template that you can download here. So, it’s easy to report your carbon emissions data and tell your customers about your efforts.