Upload a bill

Free calculator

Manufacturing site carbon calculator

Convert electricity, gas, gensets, LPG, process refrigerant, outbound freight and production waste into kgCO2e for a manufacturing site — free, region-aware, fully sourced.

Prefer to skip the typing? Upload the bill instead — the numbers get read for you, three documents a day free.

How this calculation works

A manufacturing site has more moving parts than an office, but the method doesn't change:

Emissions (kgCO₂e) = quantity used × the factor for that activity

Seven inputs, seven multiplications: electricity and gas run the building and process equipment; diesel and LPG cover gensets, forklifts, and process-heating equipment that don't run off the grid; a refrigerant top-up covers fugitive losses from process and cold-chain cooling; outbound freight covers finished goods leaving the gate by contracted haulage; and production waste covers non-hazardous solid waste from the process itself. Electricity is Scope 2; gas, diesel, LPG, and the refrigerant leak are Scope 1; outbound freight and production waste are Scope 3 (categories 4/9 and 5 respectively).

For most manufacturing sites, electricity and process fuel dominate, but the mix shifts a lot by industry — a site with heavy cold-chain refrigeration can find its R-404A top-up rivals its diesel line, and a site shipping bulky low-value goods can find outbound freight is a bigger number than its own process energy.

Why four separate fuel and gas lines

Standby generators, forklifts, and process equipment often run on fuels different from the grid electricity and piped gas that light and heat the building — and each fuel has its own combustion chemistry and therefore its own factor. Treating diesel gensets as "more electricity" or LPG process heat as "more gas" would misstate both the total and, more importantly, hide which piece of plant to target for the next efficiency or electrification project. A forklift fleet converted from LPG to electric changes the LPG line to zero and adds a small amount to the electricity line — a shift this calculator can show clearly only if the two started out separate.

Process and cold-chain refrigeration gets its own line for the same reason site-wide electricity gets a country-specific factor: R-404A carries a global warming potential of 3,943, among the highest of the commonly used refrigerant blends, because it's a mix of HFCs chosen for performance in low-temperature industrial cooling rather than for a low climate impact. A leak that would be a footnote in kilograms of gas becomes a serious line in kilograms of CO₂-equivalent once that multiplier is applied.

The factors we apply

| Activity | Factor | Unit | Source | | --- | --- | --- | --- | | Electricity | country-specific, e.g. 0.4020 (Singapore, 2024) | kgCO₂e/kWh | EMA / Ember / EPA / DEFRA | | Natural gas | 0.18293 | kgCO₂e/kWh | DESNZ 2025 | | Diesel | 2.686 | kgCO₂e/litre | DESNZ 2025 | | LPG | 1.5594 | kgCO₂e/litre | DESNZ 2025 | | R-404A refrigerant | 3,943.0 | kgCO₂e/kg | EPA GHG Emission Factors Hub 2025 | | Road freight | 0.1153 | kgCO₂e/tonne-km | DESNZ 2025 | | Production waste, landfill | 520.5327 | kgCO₂e/tonne | DESNZ 2025 |

Every factor here is published by a national government body or agency under an open licence — DESNZ (UK), EMA (Singapore), or the EPA — which is what lets this calculator run free with full source attribution on every result.

A worked example

A light manufacturing site producing packaged components tallies a month of records: 50,000 kWh of electricity, 10,000 kWh of gas for process heating, 800 litres of diesel for a standby genset and forklifts, 300 litres of LPG for a curing oven, 2 kg of R-404A topped up in the cold store, 5,000 tonne-km of contracted outbound freight, and 3 tonnes of production waste to landfill.

Electricity (Singapore factor): 50,000 × 0.4020 = 20,100.0 kgCO₂e

Gas: 10,000 × 0.18293 = 1,829.3 kgCO₂e

Diesel: 800 × 2.686 = 2,148.8 kgCO₂e

LPG: 300 × 1.5594 = 467.8 kgCO₂e

Refrigerant: 2 × 3,943.0 = 7,886.0 kgCO₂e

Freight: 5,000 × 0.1153 = 576.5 kgCO₂e

Waste: 3 × 520.5327 = 1,561.6 kgCO₂e

Total = 20,100.0 + 1,829.3 + 2,148.8 + 467.8 + 7,886.0 + 576.5 + 1,561.6 = 34,570.0 kgCO₂e ≈ 34.6 tCO₂e

The refrigerant top-up, at just 2 kilograms of gas, is the second-largest line on the page — bigger than the genset diesel, the LPG, and the freight combined. That's the pattern process refrigeration produces almost everywhere it appears: a small physical quantity, a very large GWP multiplier, and a result that's easy to miss if the top-up records aren't being kept.

What this calculator doesn't cover

  • Hazardous or licensed-disposal waste. Wastewater sludge, chemical waste, and anything requiring specialist licensed disposal isn't represented by the commercial-landfill factor used here.
  • Owned delivery fleet fuel. If the site runs its own trucks rather than contracting haulage, that diesel is Scope 1 — use the fleet fuel calculator instead of the freight field.
  • Inbound raw-material freight and purchased materials. This calculator covers outbound finished-goods freight only. Inbound logistics and the embodied carbon of raw materials fall under Scope 3 purchased goods — see the purchased goods & services calculator for a spend-based estimate.
  • Other refrigerant blends. Only R-404A is covered here. For R-410A, R-32, R-134a, R-407C, or SF6, use the refrigerant & air-con leaks calculator.
  • Process-specific combustion (e.g. furnaces, kilns). Sites with specialised high-temperature process fuel use beyond gas, diesel, and LPG should track those fuel streams against the appropriate DESNZ or IPCC factor separately.

Where this fits in your reporting

Electricity is Scope 2; gas, genset diesel, LPG, and the refrigerant leak are Scope 1; outbound freight and production waste are Scope 3. That split holds for a small parts fabricator and a large multi-line plant alike, and it's the breakdown that an ISSB IFRS S2 filing, a GRI 305 disclosure, a CDP questionnaire, or a customer's supply-chain survey will all expect in the same shape. Singapore-listed manufacturers and their suppliers can check the SGX climate reporting deadlines guide for the FY2025/FY2026 listed-issuer timeline this arithmetic feeds into. When utility bills, fuel-card statements, and service records are easier to hand over than retype, upload them directly instead.

Sources

Frequently asked questions

Why does this calculator separate diesel and LPG from electricity and gas?
Manufacturing sites commonly run standby diesel gensets, forklifts, and LPG-fired process equipment alongside their grid electricity and piped gas — four separate fuel streams with four separate combustion factors. Lumping them together would hide which piece of plant is actually driving the number, which matters when you're deciding where to invest in efficiency or electrification.
Why R-404A specifically, and not another refrigerant?
R-404A is the refrigerant most commonly used in industrial and commercial cold-chain and process refrigeration — cold stores, chillers, and process cooling loops — which is why it's the one this calculator asks for directly. It also carries one of the higher global warming potentials in common use, at 3,943, so leaks from process refrigeration are often a manufacturing site's largest single Scope 1 line after fuel combustion. If your site uses a different blend, use the refrigerant & air-con leaks calculator instead.
Is outbound freight always Scope 3 for the manufacturer?
If a manufacturer pays a third-party carrier to move finished goods to a customer or distributor, that's Scope 3 category 4 (upstream transport, from the customer's point of view it's category 9 downstream, or category 4 for the shipper depending on Incoterms). If the site runs its own delivery trucks, that fuel is Scope 1 instead — use the fleet fuel calculator for owned vehicles and this freight field only for contracted haulage.
What counts as production waste versus general office waste?
Production waste here means solid, non-hazardous waste generated by the manufacturing process itself — offcuts, packaging waste, rejected units — sent to landfill via commercial waste collection. Hazardous process waste, wastewater treatment sludge, and any waste requiring specialist licensed disposal isn't covered by the commercial-landfill factor and should be tracked separately.
Does this replace a full manufacturing LCA?
No. This gives an organizational carbon footprint under the GHG Protocol — energy, fuel, refrigerant, freight, and waste for the site as a whole. A life-cycle assessment of a specific product's carbon footprint is a different, more granular exercise that allocates emissions per unit produced. Use this calculator for site-level Scope 1/2/3 screening, not per-product LCA.