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Emission Factor Calculator

Work out emission factor instantly with clear inputs, formula shown and shareable results.

About Emission Factor Calculator

Carbon dioxide emissions follow stoichiometry: carbon oxidised times 44/12, the ratio of molecular masses. Dividing by energy content gives the emission factor in kilograms of carbon dioxide per gigajoule — about 95 for coal, 74 for oil and 56 for natural gas, which is the basis of fuel switching arguments.

Formulas

Emissions

CO2 (t) = fuel (t) x carbon content x oxidation factor x 44/12

Emission factor

Factor (kg CO2/GJ) = CO2 (t) x 1000 / energy (GJ)

Worked example

With the default values below, Emission Factor Calculator returns Carbon Dioxide Emissions of 22,506.00. Change any input above and every figure here is recalculated in your browser.

Inputs used

Fuel Consumedminimum 0 tonnes
10,000 tonnes
Carbon Contentaccepts 0–100 %
62 %
Oxidation Factoraccepts 0–100 %
99 %
Energy Contentminimum 0 GJ/t
25 GJ/t

Results

Carbon Dioxide Emissions
22,506.00
Emission Factor
90.024
Carbon Oxidised
6,138.000
Total Energy Content
250,000.0

Step by step

  1. 1Values used
  2. 2Emissions
  3. 3Emission factor
  4. 4Carbon Dioxide Emissions= 22,506.00
  5. 5Emission Factor= 90.024
  6. 6Carbon Oxidised= 6,138.000
  7. 7Total Energy Content= 250,000.0

Assumptions and limits

  • The result is derived only from the 4 inputs listed above. Anything not among them is not part of the calculation.
  • In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
  • Figures are rounded for display to 3 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.
  • Greenhouse gas reporting must use the emission factors and methodology prescribed by the applicable reporting scheme.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

Greenhouse gas reporting must use the emission factors and methodology prescribed by the applicable reporting scheme.

Frequently Asked Questions

Why is the oxidation factor less than 100%?

A small fraction of carbon leaves unburned in ash and soot. IPCC default oxidation factors are 98-100% depending on fuel and combustion technology.

Where does 44/12 come from?

Carbon has atomic mass 12 and carbon dioxide molecular mass 44, so each tonne of carbon burnt produces 3.667 tonnes of carbon dioxide.

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