Carbon Calculator

An open-source, transparent carbon footprint calculator designed for robust,
auditable, and methodology-driven carbon inventories.

Key Principles

• Separation of data domains (activity data, emission factors, conversions, parameters)
• Federated database architecture allowing customer-hosted sensitive data
• Explicit unit and pair-of-units algebra
• No black-box calculations
• Full traceability from input data to results

What This Tool Does

• Supports structured carbon calculations using calculation tabs
• Allows users to define their own mapping and scopes
• Computes results using explicit formulas and unit algebra
• Produces line results, sub-totals, and tab totals

What This Tool Does Not Do

• It does not prescribe how to map activities
• It does not automate scoping decisions
• It does not hide assumptions

Mapping decisions remain under user responsibility.
Once mapping is done, the calculator guides users through reliable calculations.

Architecture Overview

• Backend: PHP (PDO, PostgreSQL)
• Frontend: HTML / JavaScript
• Databases: Federated PostgreSQL databases
• Unit logic: Centralized in the Formula & Unit Evaluator

See /docs/architecture.md for details.

Releases

This repository follows tagged releases.
Functional updates are planned twice per year (June / December).

License

Open-source (see LICENSE file).