Carbon Footprint Calculator | Honeyguide Energy Engineering

Organisation details

This information appears on your emissions report. Set the organisational boundary first — it decides which activities belong in Scope 1 and 2 and which move to Scope 3 (e.g. leased assets, joint ventures).

Organisation name

Country / region

Reporting period start

Reporting period end

Consolidation approach

How this tool works

1. Log activities. Use the Scope 1, 2 and 3 tabs to add each fuel, vehicle trip, refrigerant top-up, purchase or utility bill as a line item. Each line is converted to CO₂e instantly.

2. Gas-by-gas, AR6 by default. Emission factors come from the UK Government (DESNZ) 2026 conversion factors. Where DESNZ publishes the CO₂/CH₄/N₂O split, the tool re-weights it with IPCC AR6 GWPs (CH₄ 27.0 for combustion, 29.8 for fossil fugitive methane; N₂O 273). Switch to AR5 in the header to match regimes that still use it (e.g. UK SECR, US EPA, UNFCCC inventories) — every total recalculates.

3. Kyoto gases in, everything else as memo items. Only the seven GHG Protocol / Kyoto gases count toward your scopes. Biogenic CO₂, Montreal Protocol refrigerants (e.g. R22), HFOs and aviation radiative forcing are reported separately as memo items, as the GHG Protocol and ISO 14064-1 require.

4. Dual Scope 2. Every electricity line carries a location-based and a market-based value. Choose which one feeds the headline total in the header; the Report shows both.

5. Review the Report tab for totals, a gas-by-gas table, memo items, AR6-vs-AR5 comparison and CSV / JSON / PDF export.

6. Nothing is sent anywhere. This tool runs entirely in your browser. Use Export session (JSON) before closing the tab if you want to resume later — import it back in on your next visit.

Fuels — stationary & mobile combustion

Gaseous, liquid and solid fuels burned on-site or in owned equipment (boilers, generators, furnaces, owned vehicles when you have fuel records). Energy units in GJ or kWh on a gross (HHV) or net (LHV) calorific value basis — check which one your supplier invoices on.

Bioenergy

Biofuels, biomass and biogas burned on-site. The CH₄ and N₂O count in Scope 1; the biogenic CO₂ is reported separately as an “outside of scopes” memo item, per the GHG Protocol.

Refrigerants & other fugitive gases AR6 / AR5 GWP

Refrigeration, air-conditioning, heat-pump and fire-suppression losses. Choose the quantification method your records support (direct top-up records, the simplified mass-balance method or a screening estimate). Blends are split into their component gases; HCFC/CFC and HFO components are reported as memo items, not in Scope 1.

Process & measured emissions

Enter emissions quantified outside this tool — continuous emissions monitoring (CEMS), process emissions (e.g. calcination, SF₆ from switchgear) or site-specific mass balances — as a mass of each gas.

Owned vehicles

Distance-based method for cars, motorbikes, vans and HGVs your organisation owns or controls. If you have fuel receipts, log the litres under Fuels instead (more accurate) — never both.

Passenger vehicles

Delivery vehicles (vans & HGVs)

Purchased electricity, heat, steam & cooling

Pick your country to auto-fill the location-based grid factor (official national factors for South Africa, the UK and the US; Ember national data for ~210 other countries), then add your market-based factor if you buy renewable certificates, have a green tariff or a PPA. Leave it blank and the location-based factor is used, as the GHG Protocol allows where no residual-mix factor exists.

Scope 3 — value chain emissions

All 15 GHG Protocol Scope 3 categories. Screen them all, then measure the relevant ones in more detail. Most categories offer DESNZ 2026 activity factors plus a supplier-specific or spend-based option.

Emissions report

Scope 1 / 2 / 3 breakdown

By category

Inventory summary

Totals — selected vs. alternative GWP basis

Emissions by greenhouse gas

Memo items — reported separately, not included in scope totals

Full activity log

Methodology notes. Accounting framework: GHG Protocol Corporate Standard, Scope 2 Guidance and Corporate Value Chain (Scope 3) Standard; consistent with ISO 14064-1:2018.
GWPs: IPCC Sixth Assessment Report (AR6), 100-year, from the GHG Protocol reference table (Aug 2024): CH₄ 27.0 (combustion and biogenic sources; fuel CO₂ factors already assume full oxidation), CH₄ 29.8 (fossil fugitive), N₂O 273, plus all HFCs, PFCs, SF₆ and NF₃. AR5 values (as used by DESNZ 2026) are available via the header toggle. Refrigerant blends are calculated from their ASHRAE 34 compositions (checked against the DESNZ AR5 blend values to within 0.03%).
Activity factors: UK Government GHG Conversion Factors for Company Reporting 2026 (DESNZ, flat file v1.2, July 2026). Where DESNZ publishes the CO₂/CH₄/N₂O split, gas masses are recovered and re-weighted to AR6; well-to-tank, waste, material, water and hotel factors are only published as CO₂e and are used as published (flagged in each hint). Vehicle, freight and hotel factors reflect UK conditions and are a widely used international default — replace them with local data where available.
Scope 2: location-based factors from DFFE South Africa (2023 grid emission factors report, NGGEF 0.906 kg CO₂e/kWh), DESNZ 2026 (UK, 2025 data), US EPA eGRID2023; other countries from Ember national data via Our World in Data, which is on a lifecycle basis and slightly overstates a combustion-only Scope 2 factor. Market-based factors are user-entered; where none is given the location-based factor is used.
Memo items: biogenic CO₂ from bioenergy (DESNZ “outside of scopes”), Montreal Protocol gases, other non-Kyoto gases, and aviation radiative forcing (flights are counted without RF unless you choose to include it).
This is a self-assessment and training tool, not a substitute for a verified GHG inventory.