How to calculate your school’s carbon footprint

Learn how to measure your school’s carbon footprint using energy bills and UK data.

Measuring your school’s carbon footprint is an important first step in cutting carbon emissions.
You cannot track progress unless you know your starting point.

A carbon footprint measures the total greenhouse gases your school produces. Greenhouse gases, such as carbon dioxide (CO₂), are a major cause of climate change. Reducing emissions helps tackle climate change and lowers energy use.

Watch the video guide

Our energy expert, Michael Esvelt, explains the best ways to calculate a school’s carbon footprint.

Why calculating your carbon footprint matters

Calculating your school’s carbon footprint can help you to:

  • set a clear baseline to measure future reductions
  • show pupils how energy use links to climate change
  • use learning from school to improve energy use at home

What emissions are included

Carbon emissions are grouped into three scopes. Schools should be aware of all three.

Scope 1: direct emissions

These come from activities you control, such as gas or oil used for heating.

Scope 2: indirect emissions from energy

These come from electricity you use, which is generated elsewhere.

Scope 3: other indirect emissions

These include travel by staff and pupils, and emissions from suppliers.

This guide focuses on scope 1 and scope 2 emissions.

If you want to learn about scope 3 emissions, visit the Carbon Trust website.

What you need before you start

To calculate your school’s carbon footprint, you will need:

  • your school’s energy bills for the year
  • total energy use in kilowatt hours (kWh) for:
    • gas or oil
    • electricity
  • the UK carbon conversion factors for the same year

You can record your figures in a simple spreadsheet.

Step-by-step: calculating your carbon footprint

Step 1: find your total energy use

Use your energy bills to find the total kWh used over the year.
Include all fuels used on site, such as gas, oil and electricity.

Step 2: find the carbon conversion factors

Get the UK government carbon conversion factors for the year you are measuring.

You will need:

  • ‘Fuels’ for gas or oil
  • ‘UK electricity’ for electricity

Use the figure called kg CO₂e per unit.

Step 3: do the calculation

For each energy source:

  1. Multiply the total kWh by the conversion factor
  2. Divide the result by 1,000
  3. This gives tonnes of CO₂ equivalent (t CO₂e)

Worked example

If your school used 250,000 kWh of gas in one year:

  • 250,000 kWh × 0.18256 (gas factor for 2023) = 45,640 kg CO₂e
  • 45,640 ÷ 1,000 = 45.64 t CO₂e

This is your scope 1 carbon footprint from gas.

Repeat the same steps for your electricity use to calculate scope 2 emissions.

Next steps

Once you know your carbon footprint, you can:

  • track changes year on year
  • see how energy-saving actions reduce emissions
  • plan further steps to cut energy use and costs

We hope this guide helps you take your first step towards reducing your school’s carbon emissions.