Carbon tracking: how to track carbon emissions, from your home to a whole company

What is carbon tracking?

Carbon tracking is measuring or estimating the greenhouse gases behind an activity and following that number over time. The result is usually given in kilograms or tonnes of CO₂, or CO₂e (CO₂-equivalent) when other gases such as methane are included.

Almost all carbon tracking, from a household to a multinational, uses the same formula:

For example, driving 12,000 km in an average petrol car at 0.163 kg CO₂e per km (UK DESNZ 2025) gives about 1,960 kg, or 2.0 tonnes, a year. The live global CO₂ counter uses the same idea at planetary scale: the world’s yearly total of 42.2 billion tonnes, spread evenly over every second.

How to track your personal carbon footprint

Five numbers cover most of a typical footprint in a high-income country. You can find all of them in about ten minutes:

1. Collect one year of data, so seasons even out.
2. Enter it in a calculator that shows its emission factors. Our carbon footprint calculator takes about two minutes and lists the three changes that would cut your total most.
3. Track monthly where it’s easy. Smart meters and energy apps show electricity and gas use by day or hour; see how to track your home energy use.
4. Repeat once a year with the same method, and compare categories rather than chasing decimals.

For context, the world average is about 4.7 tonnes of fossil CO₂ per person a year, but it ranges from well under 1 tonne in many low-income countries to over 14 tonnes in the United States. You can compare countries in the CO₂ per person ranking.

How to track carbon emissions in a business

Organisations track emissions with the Greenhouse Gas Protocol, the standard behind most corporate climate reporting. It splits emissions into three scopes (for a deeper look with examples, see scope 1, 2 and 3 emissions explained):

A practical way to start:

1. Set the boundary. Decide which sites, subsidiaries and vehicles count, and pick a base year.
2. Measure scopes 1 and 2 first. The data is in invoices you already have, and it is usually accurate to a few percent. For electricity, the GHG Protocol asks for two figures: a location-based one using the grid average, and a market-based one that reflects renewable contracts.
3. Screen scope 3. Estimate every category roughly, often from spend data, then improve the largest ones with real supplier data. For most companies, scope 3 is the biggest part of the footprint.
4. Choose emission factors and document them: for example the UK government’s annual conversion factors or the US EPA Emission Factors Hub. Use the same sources every year.
5. Report and set targets. A growing number of disclosure rules, including the EU’s Corporate Sustainability Reporting Directive and the ISSB’s climate standard, build on the GHG Protocol, so tracking it well now saves work later.

Real-time carbon tracking: is it possible?

Partly. It helps to separate what is actually measured as it happens from what is estimated:

• Power plant stacks: large US power plants measure CO₂ continuously and report hourly data, published through the EPA’s Clean Air Markets Program Data.
• Electricity grids: Great Britain’s grid operator publishes carbon intensity every half hour with a forecast, and Electricity Maps shows live estimates for many countries. Useful for timing laundry, EV charging or data-centre work.
• Smart meters: they record your home’s electricity and gas use every half hour or hour; multiply by a factor to get near-real-time household emissions.
• Daily national estimates: Carbon Monitor estimates CO₂ emissions by country and sector each day from power, traffic and industry data.
• Facility-level estimates: Climate TRACE combines satellite imagery and machine learning to estimate emissions from millions of individual sources.
• Satellites: NASA’s OCO-2 measures CO₂ concentrations in the air, not emissions directly; turning them into emissions takes modelling.

Global totals are different: the Global Carbon Budget is published once a year. A live CO₂ tracker such as ours spreads that yearly estimate over every second, so it shows the expected running total, not a measurement. How the counter works explains the method and its uncertainty.

What to look for in a carbon tracking tool or dashboard

• It shows its emission factors and sources, with the year. A tool that hides them can’t be checked.
• It uses your real activity data (kWh, litres, km) rather than spending alone where you have it.
• It follows the GHG Protocol scopes and reports location- and market-based electricity separately.
• It keeps an audit trail: who entered what, from which invoice, and when factors changed.
• It shows trends, not just a total: by month, site and category, so you can see what is working.
• It exports your data in an open format, so you are not locked in.

For a household, a spreadsheet plus our calculator is enough. Small businesses often manage scopes 1 and 2 in a spreadsheet too; dedicated carbon accounting software earns its cost once scope 3 data, multiple sites or audits come in.

Common carbon tracking mistakes

• Mixing units: kWh and MWh, miles and kilometres, CO₂ and CO₂e. Write the unit next to every number.
• Using an old or wrong-country factor: grid factors change every year as renewables grow; the UK’s fell to about 126 g/kWh in 2025, while the world average is about 458 g.
• Double counting: counting electric car charging in both “car” and “electricity”, or a supplier’s emissions in two scope 3 categories.
• Changing the method every year, which makes progress impossible to see. If you must change it, restate the base year.
• Chasing precision on small items while estimating the biggest category roughly. Spend your effort where the tonnes are.

Want to see the big picture? Watch the world’s emissions add up on the live CO₂ counter, or compare countries in the CO₂ emissions by country ranking.