How to calculate your business carbon footprint
Calculating your business carbon footprint sounds daunting. Done properly, it is a structured process that follows a well-established methodology. This guide walks through each step and explains what data you actually need to get started.
Tool via The Carbon Workbench
Calculating your business carbon footprint sounds daunting. Done properly, it is a structured process that follows a well-established methodology. This guide walks through each step and explains what data you actually need to get started.
The methodology: GHG Protocol
The Global GHG Protocol Corporate Standard is the framework used by the vast majority of businesses worldwide for emissions accounting. It defines the three scope categories (see our guide to Scope 1, 2 and 3) and the rules for how to calculate each. CSRD, the SBTi, and most other reporting frameworks are built on GHG Protocol foundations.
You do not need to read the full standard to calculate your footprint. What you need is: the right data sources, the right emissions factors, and a structured approach to organising the calculation.
Step 1: define your boundary
Before calculating anything, decide what is included. Most businesses use the operational control boundary — all facilities and operations you control. This is distinct from the equity share boundary (your proportional share of all entities you have an ownership stake in), which is more complex and less common for SME reporting.
Also decide your base year — the year your emissions data represents. This becomes your baseline against which future reductions will be measured. Consistency matters: use the same boundary definition and methodology each year.
Step 2: collect Scope 1 data
For Scope 1, you need consumption data for every fuel source you burn directly. Work through each facility:
- Natural gas: annual gas consumption in kWh or cubic metres (from utility bills)
- Diesel and petrol: total litres consumed by owned/leased vehicles (from fuel cards or purchase records)
- Heating oil, LPG: litres purchased
- Refrigerants: kg of refrigerant gas added during maintenance (from engineer records)
Step 3: collect Scope 2 data
For Scope 2, you need your electricity consumption in kWh (from meter readings or bills) for each site. If you have purchased renewable electricity certificates or a green tariff, document this for the market-based calculation.
Step 4: collect Scope 3 data
Scope 3 is the most involved. Start with the categories most likely to be material for your business type:
| Business type | Most material Scope 3 categories | Data source |
|---|---|---|
| Professional services | Business travel, employee commuting, purchased IT services | Expense reports, travel management system, HR commute survey |
| Retail / e-commerce | Purchased goods, upstream logistics, downstream delivery | Spend data, supplier emissions disclosures, logistics records |
| Manufacturing | Purchased goods (raw materials), upstream energy, waste, logistics | Procurement data, waste disposal records, supplier data |
| Food and agriculture | Agricultural inputs, land use, product use, waste | Specialist agricultural LCA databases |
Step 5: apply emissions factors
Emissions factors convert activity data (kWh consumed, litres burned, £ spent) into CO₂e. The UK government publishes updated emissions factors annually through the BEIS/DESNZ Conversion Factors spreadsheet — this is the standard source for UK reporting. For international operations, the IPCC emissions factor database and regional equivalents apply.
For Scope 3 spend-based estimates, the UK BEIS supply chain emissions factors provide category-level intensity figures. These are less accurate than supplier-specific data but are a valid starting point.
Step 6: calculate and report
Total your Scope 1, 2, and material Scope 3 emissions in tCO₂e. Break them down by scope and, within Scope 3, by category. This structure is what CSRD and most voluntary reporting frameworks expect.
Tool via The Carbon Workbench
The Carbon Workbench Business Carbon Footprint tool walks through each step of this calculation, applies the current UK emissions factors automatically, and generates a structured summary you can use for reporting or internal decision-making.
Key takeaway
A business carbon footprint follows a clear methodology: define your boundary, collect fuel and energy data for Scope 1 and 2, gather spend or activity data for material Scope 3 categories, apply the right emissions factors, and total in tCO₂e. The BEIS/DESNZ Conversion Factors are the authoritative source for UK reporting. Start with Scopes 1 and 2 in your first year, and add Scope 3 as your data collection improves.