Carbon Footprint Calculator
Estimate Scope 1, 2 and 3 GHG emissions in line with the GHG Protocol, structured for CSRD/ESRS E1, UK SECR, California SB253/261 and ISSB IFRS S2 disclosure — brought to you by The ESG Institute.
Download the user guide (PDF)Organization & reporting setup
Filled once, used across both the quick estimate and the detailed calculator.
Quick Estimate
A directional number based on typical emissions intensity for organizations of your size and sector. Good for a first read — not a substitute for the detailed calculator when you need audit-ready figures.
Scope 1 — Direct emissions
Fuel burned on-site or in owned/leased vehicles, plus refrigerant leaks from owned equipment.
| Facility / asset | Fuel / source (Select) | Quantity | Unit | tCO2e | Data quality (Select) ? |
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About this carbon footprint calculator
The ESG Institute built this calculator for businesses that need a greenhouse gas number and do not have a sustainability team to produce one. It runs in your browser, costs nothing, and works in ten languages: English, Spanish, French, German, Italian, Portuguese, Chinese, Vietnamese, Malay and Russian.
What it measures
The tool follows the GHG Protocol Corporate Standard and covers all three emission scopes. Scope 1 captures fuel you burn on site and in vehicles you own or lease, plus refrigerant leaks from your own equipment. Scope 2 covers the electricity, heat and steam you buy, reported both location-based and market-based as the GHG Protocol requires. Scope 3 covers your value chain, with full calculators for business travel, employee commuting, purchased goods and services, and waste, plus a screening step across all fifteen Scope 3 categories so nothing gets quietly left out.
You can work in either of two modes. The Quick Estimate gives you an order-of-magnitude figure in about two minutes using sector benchmarks. The Detailed Calculator takes line-item activity data, tags every row by data quality and produces a structured inventory suitable as a working basis for professional review and verification.
Which reporting frameworks it supports
Choose your target framework in the setup panel and the results and PDF report adjust their footnotes to match. The calculator supports the EU Corporate Sustainability Reporting Directive (CSRD) and ESRS E1, the UK's Streamlined Energy and Carbon Reporting (SECR), California SB253 and SB261, and ISSB IFRS S2. The underlying calculation follows the GHG Protocol in every case, because these reporting regimes use or reference it for greenhouse gas emissions methodology.
Where the emission factors come from
The calculator uses published government and scientific sources wherever suitable factors are available. UK fuel and grid electricity factors use DESNZ/DEFRA's 2026 GHG Conversion Factors. US grid factors use EPA eGRID2023. France uses RTE's 2025 Bilan électrique, and India uses the Central Electricity Authority's CO2 Baseline Database v21.0. Refrigerant global warming potentials follow IPCC AR6.
Some markets, including China, Japan and Australia, use indicative estimates drawn from Ember, IGES and national sources rather than a single official government factor. Spend-based emissions use a generic economic input-output proxy rather than a country-specific input-output table. These limitations are flagged inside the tool. The full source list, with a verification status against each factor, appears on the results screen. This release reflects the September 2026 methodology refresh.
Who it's for
Small and mid-sized businesses building their first inventory, sustainability managers who need a defensible baseline, and finance teams working towards a disclosure deadline. The output is an estimate rather than assured data, so anything intended for a regulatory, investor or other external filing should be independently verified by a qualified professional first.
Get your PDF report
Enter your details and we'll generate your GHG summary report immediately — no waiting, no separate email required.
