The new Carbon Calculator is now available
The Carbon Calculator supports annual corporate carbon reporting for organisations and supply chain emissions management for subscribing Scope 3 Carbon Calculator partners.
It is now accessed through your Supply Chain Sustainability School company dashboard, bringing carbon reporting, supplier engagement and learning together in one place.
A shared approach to company and supply chain reporting
The Carbon Calculator gives organisations a consistent way to report their annual corporate emissions and share them with multiple clients. It also helps clients and main contractors build a clearer picture of supply chain emissions, moving from estimates towards better supplier-reported data.
For organisations and suppliers
Create a free corporate carbon report for each reporting year, covering Scopes 1, 2 and 3. Enter activity data such as fuel and electricity use, business travel, materials, waste and water, and the Calculator applies the relevant UK Government greenhouse gas conversion factors to calculate your emissions, aligned to the GHG Protocol reporting framework. Reports can be shared with participating clients and main contractors, reducing the need to respond to multiple carbon data requests.
For clients and main contractors
Scope 3 Carbon Calculator partners can use the platform to understand emissions across their supply chain. Spend-based estimates provide an initial picture where supplier data is unavailable, while supplier-reported information improves the quality and accuracy of that picture over time.
While the Calculator focuses on corporate reporting, supplier-reported data can be combined with project- and product-level information to provide a more complete picture of emissions and reduce reliance on generic or spend-based estimates.
By using a common platform and reporting approach, School Partners can engage suppliers consistently, identify where better data is needed and support improvements in supply chain carbon reporting.
What’s new?
The Carbon Calculator is now part of the Supply Chain Sustainability School.
The new Carbon Calculator includes:
- One access point through your School company dashboard
- More flexible annual reporting periods to align with different financial years
- Clearer dashboards and reporting outputs
- Improved data checks and guidance
- One-to-many reporting to multiple clients
- Supply chain reporting that combines spend-based estimates with supplier-reported emissions data
If you do not yet have a School account, registration is free. Where possible, join your organisation’s existing School company account rather than creating a duplicate company.
Frequently Asked Questions
Your access depends on your user role. You will need Carbon Reporter or administrator permissions to create, edit and submit your organisation’s carbon reports.
Your School Account Admin can update your role through the Our people section of the company dashboard.
We are still migrating accounts and historic data from the previous Carbon Calculator. If your data is not yet visible, it has not been lost; we may still be matching it to the correct School company account.
Please check that your company profile details, including your Company Registration Number where applicable, are correct. If you need your data urgently or believe it has been linked incorrectly, complete the data migration form. We may also be able to provide your historic data as a CSV while the migration is completed.
Submit request form
Join our live webinar for a walkthrough of the new Carbon Calculator, including how to access it, complete your corporate carbon report and share it with clients.
Tuesday, 29 September 2026, 12:00 PM–1:00 PM
The webinar will include a live demonstration and time for questions.
Register for the webinar here
When submitting a report, you choose which participating clients and main contractors to share it with. Those organisations can view the report but cannot edit your data.
Your report is not publicly available or visible to other organisations unless you choose to share it with them.
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