Skip to content

A specification that describes how to calculate a carbon intensity for software applications.


Notifications You must be signed in to change notification settings


Repository files navigation

Software Carbon Intensity (SCI) Specification

A specification that describes how to calculate a carbon intensity score for software applications.

Created and managed by the Standards Working Group in the

Project Scope

This document, the Software Carbon Intensity technical specification, describes how to calculate the carbon intensity of a software application. It describes the methodology of calculating the total carbon emissions and the selection criteria to turn the total into a rate that can be used to achieve real-world, physical emissions reductions, also known as abatement.

Electricity has a carbon intensity depending on where and when it is consumed. An intensity is a rate. It has a numerator and a denominator. A rate provides you with helpful information when considering how to design, develop, and deploy software applications. This specification describes the carbon intensity of a software application or service.

Getting Started

  • The development version of the specification is here.
  • The latest published version of the specification is here.
  • The dev branch contains the current version that is being worked on and the main branch contains the latest published version.
  • Check the issues tab for active and closed conversations regarding the spec.

GitHub Training


The recommended approach for getting involved with the specification is to:

  • Read the development version of the specification.
  • Raise an issue, question, or recommendation in the issues tab above and start a discussion with other members.
  • Once agreement has been reached, then raise a pull request to update the specification with your recommended changes.
  • Let others know about your pull request by either commenting on the relevant issue or posting in the Standards Working Group slack channel.
  • Pull requests are reviewed and merged during Standards Working Group meetings.
  • Only chairs of the Standards Working Group can merge pull requests.



Standard WG projects are copyrighted under Creative Commons Attribution 4.0.


Standard WG projects are licensed under the MIT License - see the file for details.


Standard WG projects operate under the W3C Patent Mode.