What do spend-based and activity-based mean in the GHG Protocol?

• Spend-based calculation

  From the English "money spend". Based on reporting financial data. You use purchase costs and multiply them by standard emission factors, for example 'kg CO₂e* per krona spent'. It's quick, easy and often works well for Scope 3 emissions** when detailed data is missing.

• Activity-based costing

  Uses actual data on how much was actually used or performed - for example, number of liters of fuel, kWh of electricity, tons of waste or kilometers of transport. It requires more detailed data collection but provides far better accuracy.

Advantages and disadvantages of spend-based and activity-based

How to move from spend to activity-based data?

For many businesses, a spend-based calculation can be a first step - but our advice is that it should not be your final destination. If the price of a product you have purchased goes up, it may appear that emissions from that product are increasing - even though you have not increased your purchases. Therefore, spend-based data can be misleading.

By gradually increasing the share of activity-based data, you can build a more robust and actionable climate strategy that enables accurate monitoring over time.

- Activity-based data allows you to follow up data accurately over time, so you can improve your calculation in accordance with the GHG protocol, says Johan Hodell, head of team calculation & strategy at ZeroMission. 

That's how you can start:

1. Identify the biggest sources of emissions in your organization - called "hotspots" in Scope 3. Depending on the type of company, it could be travel, purchasing or produced goods.
2. Prioritize areas where activity data is available - for example, electricity consumption or transport.
3. Engage suppliers - ask for product or supplier-specific emissions data. The emissions of a produced good can differ greatly depending on factors such as material choice and country of production, so don't be afraid to ask.
4. Automate data collection - digital tools or integrated systems can help if they are available.

Whatever the method, it is important to regularly update your calculation to monitor the impact of the climate actions you take within your organization.

From calculating carbon emissions in the GHG Protocol to action

In short, activity-based climate accounting allows you to see the impact of concrete actions, such as internal energy efficiency, transport optimization or supplier selection. It also gives you a better basis for transition plans and climate financeand can strengthen your credibility in communicating climate targets and net-zero strategies.

So moving from spend to activity is not just about improving data quality - it's about creating real climate benefits.

At ZeroMission , we use a sustainability reporting platform based on a database of over 100,000 emission factors. This allows you to easily track your actual activity-based emissions over time while maintaining high accuracy - without having to be a climate expert yourself.

Our sustainability strategists will help you along the way.

*carbon dioxide equivalent - a concept that means that all greenhouse gases, not just carbon dioxide, have been taken into account.

**Scope 3 - Greenhouse Gas Protocol's designation of indirect emissions, i.e. emissions that occur outside your value chain