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Fuel heating value and equivalence

Compare three fuels by the cost of useful heat, see how much of each delivers the same energy and how moisture cuts biomass heating value.

Pre-sizing and estimating tool: results do not replace design, calculations or reports signed by a licensed professional, nor verification against the applicable codes and standards.

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Heat demand
Fuel 1
Fuel 2
Fuel 3
—Fuel with the lowest cost per useful heat
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Cost per GJ of useful heat

Price per GJ of LHV divided by equipment efficiency.

Tap the chart to see the values.

Biomass LHV versus moisture

Lower heating value as received, per ISO 18125, for the biomass fuels in the list.

Tap the chart to see the values.

Equivalence between the fuels

Quantity of each fuel delivering the same useful heat, including each equipment efficiency.

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Method, assumptions and references

Equations used

Biomass LHV (ISO 18125): LHVar = (HHVd − 0.2122·H − 0.0008·(O + N)) × (1 − M/100) − 0.02443·M [MJ/kg]
Gas and liquid HHV from LHV: HHV = LHV + 9 · H · 2.442 [MJ/kg]
Cost per useful GJ = price per GJ (LHV) ÷ efficiency
Fuel use = useful heat ÷ (efficiency × LHV)

Assumptions and limits

  • Default LHVs: natural gas from EPA 40 CFR 98 Table C-1 (1,026 Btu/scf HHV) converted to LHV; liquids from EPE (Brazil) factors, close to EPA defaults. Adjust to your supplier’s certificate.
  • Biomass with typical wood composition (C 49%, H 6%, O 44%, dry basis); bagasse C 47%, H 6.3%.
  • Hydrogen mass share used for HHV: natural gas 24%, propane 18%, residual oil 11%, distillate 13.3%.
  • Gas volumes at the supplier’s reference condition (scf at 60 °F and 14.696 psia in the U.S.; m³ at 20 °C and 1 atm in Brazil).

Standards and technical documents

  • ISO 18125:2017: Solid biofuels — Determination of calorific value
  • ISO 17225-1:2021: Solid biofuels — Fuel specifications and classes
  • ISO 6976:2016: Natural gas — Calculation of calorific values, density, relative density and Wobbe indices from composition
  • ASTM D240: Heat of Combustion of Liquid Hydrocarbon Fuels by Bomb Calorimeter
  • EPE, Balanço Energético Nacional; ANP, Anuário Estatístico 2026: fatores de conversão, massas específicas e PCI
  • EPA 40 CFR Part 98, Table C-1: Default CO2 emission factors and high heat values for various types of fuel

U.S. regulations

  • EPA 40 CFR Part 98, Subpart C: greenhouse gas reporting for stationary combustion (uses Table C-1 heat values)
  • EPA 40 CFR Part 63, Subparts DDDDD and JJJJJJ: boiler emission standards by fuel category
  • FERC and state PUC tariffs: natural gas billed on a heat-content (therm or MMBtu, HHV) basis

Frequently asked questions

How much wood equals 1 MMBtu of natural gas?

At about 5,000 Btu/lb LHV for wood at 30% moisture, 1 MMBtu of gas (HHV) holds the energy of about 180 lb of wood. With 88% efficiency on gas and 78% on wood, it takes about 200 lb of wood for the same useful heat.

What is the difference between LHV and HHV?

HHV includes the condensation heat of the water formed in combustion; LHV does not. For natural gas, HHV is about 11% higher than LHV; for dry wood, about 7%.

Why compare cost per useful heat?

Because each piece of equipment has a different efficiency. A fuel that is cheaper per MMBtu can cost more per useful MMBtu if its boiler is less efficient.