Fifteen self-contained calculators spanning the full corporate inventory — Scope 1, 2 and 3, plus target-setting, financed emissions and climate disclosure.
Live preview · greencalculus.com · Methodology · Standards
Self-contained, reusable reference implementations of corporate carbon-accounting calculators — built for sustainability officers, engineers, and CSRD compliance teams. The gallery walks the whole corporate inventory: roll everything up in the GHG Inventory Aggregator, then drill into Scope 1 (combustion), Scope 2 (electricity, dual reporting) and Scope 3 (business travel
- the value-chain suite) — alongside SBTi targets, FLAG land emissions, PCAF financed emissions and EU CBAM border carbon.
Each calculator is a single HTML file: vanilla JavaScript, zero dependencies, built to GHG Protocol and IPCC AR6 — fork it, read it, embed it. Open a calculator, or jump to the full live version.
| Calculator | Scope | Live version |
|---|---|---|
| 📊 GHG Inventory Aggregator | Consolidate Scope 1 + 2 + 3 → dual location/market grand totals + scope split | Open live ↗ |
| 🔥 Scope 1 Stationary Combustion | Direct fuel combustion → tCO₂e, 10 fuel types | Open live ↗ |
| ⚡ Scope 2 Electricity | Purchased electricity → tCO₂e with dual location-based + market-based reporting (EAC/PPA/residual mix) | Open live ↗ |
| Category 6 air/rail/road/hotel + radiative-forcing uplift; hub to the full Scope 3 value-chain suite | Open live ↗ | |
| 🎯 SBTi Near-Term Target | Science-based target via Absolute Contraction | Open live ↗ |
| 🌿 FLAG Emissions | Forest, Land & Agriculture — LUC + LM + Removals | Open live ↗ |
| 💰 PCAF Financed Emissions | All 7 PCAF Part A asset classes + DQ score; hub to the 10-calc suite | Open live ↗ |
| 🛂 CBAM Quarterly Reporting | Embedded emissions + certificate liability across the 6 CBAM goods; hub to the 12-calc disclosure suite | Open live ↗ |
| 🌾 Scope 1 Biomass & Biofuel | Biogenic + fossil split → fossil CO₂e in Scope 1, biogenic CO₂ as a memo | Open live ↗ |
| 🚢 Scope 1 Marine & Aviation Fuel | Own ships & aircraft (MGO/HFO/Jet A-1/avgas) → tCO₂e + aviation RF memo | Open live ↗ |
| ⚙️ Scope 1 + 2 CHP / Cogeneration | Allocate CHP fuel emissions across power & heat (efficiency method) | Open live ↗ |
| ♨️ Scope 2 Purchased Steam & Hot Water | Steam/hot water → tCO₂e, location + market (supplier back-calc) | Open live ↗ |
| 🔌 Scope 2 Residual Mix | AIB / Green-e residual factor on untracked electricity (market-based) | Open live ↗ |
| 🔋 Scope 2 Renewable Procurement | REC / PPA / VPPA / onsite vs residual mix; reduction % | Open live ↗ |
| 🌡️ Scope 2 District Heating & Cooling | District heat & cooling → tCO₂e, location + market | Open live ↗ |
The landing page (index.html) is a gallery linking all fifteen calculators.
The capstone of a corporate carbon inventory — consolidates the three scopes into one auditable total.
Because Scope 2 is reported two ways, the inventory carries two grand totals:
location-based = S1 + S2(location) + S3 and market-based = S1 + S2(market) + S3 — the same Scope 1 and
Scope 3 flow into both, only the Scope 2 line differs. Enter scope subtotals (with Scope 3 split into the
material categories), pick the headline basis, and get the dual totals, a scope-split bar, and the
Scope 3 share of total — which for most companies is 70–90%. This is the consolidated inventory that
CSRD/ESRS E1, SECR, IFRS S2 and CDP expect.
- Standard: GHG Protocol Corporate Standard — Scopes 1, 2 & 3
- Method: inventory consolidation · dual Scope 2 totals · scope-split apportionment
Converts fuel burned in owned or controlled equipment into tCO₂e across 10 fuel types (natural gas in kWh GCV and m³; diesel, petrol, LPG, fuel oil, kerosene; industrial and domestic coal; wood-chip biomass). Outputs a full calculation breakdown: emission factor, GWP basis, raw kg result, and annualised figure.
- Standard: GHG Protocol Corporate Standard — Scope 1
- Factors: UK DESNZ 2024 · GWP: IPCC AR6 GWP-100
Reports purchased electricity two ways at once, as the GHG Protocol Scope 2 Guidance requires in
markets with energy attribute certificates. The location-based method applies the average grid factor
for where power is consumed; the market-based method reflects contractual instruments —
market = covered share × 0 + uncovered share × residual mix. Pick a grid, choose an instrument (residual
mix, EACs — RECs/GOs/REGOs/I-RECs, a PPA, or a supplier-specific factor), set the renewable coverage, and
watch certificates drive the market-based number toward zero while the location-based number holds.
- Standard: GHG Protocol Scope 2 Guidance — dual reporting
- Factors: IEA / Ember location factors · AIB & EPA eGRID residual mix · GWP: IPCC AR6 GWP-100
Calculates GHG Protocol Scope 3, Category 6 travel with the activity method —
emissions = activity × factor — across air (domestic, short-haul, long-haul economy & business), rail,
car/taxi, and hotel stays, with the optional radiative-forcing uplift (×1.9) for the non-CO₂
high-altitude effects of flying. Doubles as a hub linking the full Scope 3 value-chain suite (23 live
calculators across Categories 1–14): spend-based purchased goods, well-to-tank, T&D losses, freight by six
modes, waste, commuting & WFH, leased assets, use of sold products, end-of-life, franchises, and more — all
rolled up by the GHG Inventory Aggregator.
- Standard: GHG Protocol Corporate Value Chain (Scope 3) — Category 6
- Factors: UK DESNZ 2024 (pax-km / room-night) · GWP: IPCC AR6 GWP-100
Builds a science-based near-term target with the Absolute Contraction Approach (ACA) —
target = baseline × (1 − rate)^years. Picks an ambition tier (Minimum 1.5°C, Accelerated,
Leadership, or custom rates), tests Scope 3 materiality (the ≥40% trigger and ≥67%
coverage rule), validates the 4.2%/yr Scope 1+2 floor, and projects a year-by-year
reduction trajectory with cumulative cuts.
- Standard: SBTi Corporate Near-Term Criteria · GHG Protocol · IPCC AR6 WG3
- Method: Absolute Contraction Approach (used by >90% of validated companies)
Calculates Forest, Land & Agriculture emissions across three pillars reported as separate inventory lines: Land Use Change (one-time deforestation stock loss, optionally amortised over 20 years; ongoing peatland drainage), Land Management (annual biogenic CH₄/N₂O from livestock, nitrogen fertiliser, rice, and crop-residue burning), and Carbon Removals (forestry and soil sequestration — reported separately, never netted). Includes the SBTi FLAG 20% eligibility check.
- Standard: GHG Protocol Land Sector & Removals Standard (2026) · SBTi FLAG
- Factors: IPCC AR6 Tier 1 · DEFRA 2025 · GWP: IPCC AR6 GWP-100
One universal engine for all 7 PCAF Part A asset classes — financed emissions = (outstanding ÷ denominator) × investee emissions. Selecting an asset class relabels the
attribution denominator (EVIC, total equity + debt, property value at origination,
PPP-adjusted GDP, …), computes the attribution factor and the auto-derived PCAF
data-quality score (1–5), and deep-links to that class's live calculator. Doubles as a
hub linking the full 10-calculator PCAF suite (Part A, facilitated, insurance-associated,
and the cross-asset data-quality tool).
- Standard: PCAF Global GHG Accounting & Reporting Standard (Financed Emissions)
- Method: attribution-factor accounting · auto-derived data-quality score
Estimates the embedded emissions of EU imports across the six CBAM goods (cement, iron
& steel, aluminium, fertilisers, hydrogen, electricity) — embedded = quantity × (direct + indirect intensity) — then layers on the certificate liability: the 2026–2034 phase-in
(2.5% rising to 100% as EU ETS free allocation is withdrawn) and a rebate for any carbon
price already paid in the country of origin. A transitional toggle reflects the report-only
period through 2025. Doubles as a hub linking the full 12-calculator climate disclosure &
compliance suite (EU ETS, CSRD E1, IFRS S2, TCFD, CDP, SECR, SEC, CA SB-253/261, AASB S2,
Singapore).
- Regulation: (EU) 2023/956 — Carbon Border Adjustment Mechanism
- Method: embedded-emissions accounting · phase-in factor · origin carbon-price rebate
- Note: intensity defaults are illustrative; the live tool uses the Commission's published default-value tables per good and country of origin
| Property | Detail |
|---|---|
| Dependencies | Zero — Vanilla JS only |
| Rendering | Modern CSS, clamp() fluid typography, dark theme |
| Numbers | JetBrains Mono, tabular-nums |
| Hosting | GitHub Pages |
| License | MIT |
Note: these are simplified, self-contained reference implementations. The production calculators on GreenCalculus.com read live emission factors from the Master Brain data layer and add full audit trails, export, and uncertainty disclosure.
All emission factors and GWP values are documented in: → greencalculus/greencalculus-methodology
Fifteen open reference calculators from the GreenCalculus traceable carbon-accounting platform — built for sustainability officers, engineers, and CSRD compliance teams.
Built and maintained by Jeremiah Say — Lead Systems Architect · GHG Protocol · IPCC AR6 · CSRD/ESRS E1 · SBTi · PCAF
MIT