Producing renewable natural gas from dairy manure? Use the dedicated dairy RNG calculator — it uses a farm-level herd and digester model instead of these sections.
Fuel pathway
Feedstock production
Cultivation, fertiliser and field N2O, collection, rendering and drying, per tonne of feedstock.
Feedstock transport
Add one leg per movement, choose the mode and distance; emissions scale with the mass hauled.
Process energy sources
One parameter per row — choose the supply, the amount and the unit.
Chemicals and fugitive emissions
Process chemicals and catalysts per tonne of fuel, plus methane, nitrous oxide, vented CO2 and carbon storage.
Co-products and avoided emissions
Displacement credits for co-products, exported power and avoided methane, plus optional energy allocation.
Fuel distribution
Finished fuel movements, terminal storage, blending, dispensing, compression and losses.
Tailpipe and end use
Point-of-use methane and nitrous oxide by end-use mode, fossil carbon share and aftertreatment.
16.33
gCO2e / MJ of renewable diesel (hefa) — used cooking oil
Detailed results are a premium feature
The free calculator shows the headline carbon intensity for your scenario. Premium members also get the emission source breakdown, the full line-by-line emissions table, the regulatory program comparison and the Excel export with all background factors.
How a biofuel CI score is calculated
Every carbon intensity score follows the same lifecycle logic used by programs such as California's LCFS, Oregon's CFP, Canada's CFR and the EU's RED. The calculator above walks through exactly these stages.
1. Count feedstock production emissions
Start with growing or collecting the feedstock: fertiliser, field energy and land-use effects for crops, or collection and pre-processing for wastes and residues. Waste feedstocks such as used cooking oil or manure typically carry a much smaller production footprint than purpose-grown crops.
2. Add transport to the facility
Emissions from moving the feedstock to the processing plant depend on distance and mode — truck, rail, barge or ocean vessel each carry a different emission factor per tonne-kilometre.
3. Add processing energy and inputs
Conversion is usually the largest term: electricity, natural gas, propane, diesel, steam, hydrogen or biomass used in the plant, plus chemicals and fugitive emissions. The electricity grid region matters — the same pathway scores very differently on a coal-heavy grid versus a hydro-heavy one.
4. Subtract co-product credits
Most pathways make more than one product — animal feed, renewable power, glycerine or captured CO2. Programs credit the fuel for the products it displaces, which lowers the score and can push some pathways below zero.
5. Add distribution and finishing
Include the fuel's journey to the end user — transport to blending terminals or airports, blending, and any program-specific adjustments such as tailpipe factors or energy economy ratios.
6. Divide by the fuel's energy content
Total lifecycle emissions divided by the fuel's energy gives the CI score in gCO2e/MJ. Comparing it with each program's benchmark gives the GHG saving: (benchmark − CI) ÷ benchmark. A pathway earns credits when its CI sits below the benchmark.
Carbon intensity questions, answered
- How is the carbon intensity of a biofuel calculated?
- Add up the lifecycle emissions — feedstock production, transport, processing energy and chemicals, distribution — subtract co-product and avoided-emission credits, then divide by the fuel's energy content. The result is expressed in grams of CO2-equivalent per megajoule (gCO2e/MJ).
- What units is carbon intensity measured in?
- The standard unit is gCO2e/MJ — grams of carbon-dioxide-equivalent emissions per megajoule of fuel energy. Some programs express benchmarks the same way, which allows a direct comparison between a pathway score and the program baseline.
- How is carbon intensity calculated for California's LCFS?
- The Low Carbon Fuel Standard scores each fuel pathway against an annual declining benchmark for gasoline and diesel. Pathways with a CI below the benchmark generate credits; those above it generate deficits. The scoring follows CA-GREET, which uses the same lifecycle stages shown in this calculator.
- Can a biofuel have a negative carbon intensity?
- Yes. Pathways that avoid emissions elsewhere — dairy manure RNG capturing methane that would otherwise escape, for example — can score below zero once the avoided-emission credit exceeds all other lifecycle emissions. This calculator shows negative scores on a signed scale.
- What is a good carbon intensity score?
- It depends on the benchmark. Fossil diesel sits near 100 gCO2e/MJ and the California LCFS diesel benchmark declines each year; ethanol pathways often land around 50–70, waste-based biodiesel and renewable diesel around 20–40, and some RNG pathways below zero. Use the program comparison in the calculator to see where a pathway stands.