What is the difference between LHV and HHV?

Lower Heating Value (LHV) is the heat released when fuel combusts and exhaust gases leave as water vapor — the practical value for engines and turbines that exhaust above the dew point. Higher Heating Value (HHV) additionally recovers the latent heat of condensing water vapor, so it is always larger. Most engine efficiency figures are based on LHV; boiler and fuel-cell specs sometimes use HHV.

Why are the values per unit volume different for ethanol vs. gasoline?

Ethanol has a lower energy density by volume (roughly 21 MJ/L LHV vs. 32 MJ/L for gasoline) because the oxygen bound in the ethanol molecule reduces the net heat released per kilogram, and ethanol is also denser than gasoline. A tank of E100 contains about 66% of the energy of the same volume of gasoline.

What units can I use for natural gas?

Natural gas is measured by volume (cubic meters, m³) at standard conditions (15 °C, 1 atm). The tabulated value used here is approximately 34.2 MJ/m³ LHV for typical pipeline-quality gas. Actual values vary with gas composition and local standards.

Are these values exact for all fuel grades?

The values are standard reference averages. Real fuels vary slightly: summer vs. winter gasoline blends, biodiesel feedstock, hydrogen purity, and natural gas composition all affect heating value by a few percent. For engineering design, verify against a fuel specification sheet for the exact batch.

Can I use this for E10 or E85 blends?

This tool covers neat fuels. For blends like E10 (10% ethanol, 90% gasoline), calculate each component's energy separately and add them. For example, 10 L of E10 = 1 L ethanol energy + 9 L gasoline energy.

Fuel Energy Content Calculator

Name: Fuel Energy Content Calculator
Availability: InStock
Author: Nham Vu

Select a fuel, enter a quantity, and instantly get total energy content in MJ or BTU using LHV and HHV values.

Fuel & Quantity

Fuel type

Quantity

Unit

Output energy unit

Megajoules (MJ) BTU

Enter a quantity and press Calculate

Reference: Heating Values

Fuel	Unit	LHV (MJ)	HHV (MJ)

Summary

Select a fuel, enter a quantity, and instantly get total energy content in MJ or BTU using LHV and HHV values.

How it works

Select a fuel type from the dropdown (gasoline, diesel, LPG, natural gas, ethanol, hydrogen, or biodiesel).
Choose the quantity unit appropriate for that fuel (liters, US gallons, kg, or m³).
Enter the quantity of fuel.
Select the output energy unit — megajoules (MJ) or BTU.
The tool displays total LHV energy, total HHV energy, and the HHV/LHV ratio.

Use cases

Compare the energy content of a tank of gasoline versus the same volume of ethanol.
Estimate the energy available in a known mass of hydrogen for fuel cell sizing.
Convert a natural gas meter reading (m³) into MJ or BTU for cost-per-energy analysis.
Check how much diesel energy is equivalent to a given volume of biodiesel.
Determine total BTU in a propane (LPG) cylinder for HVAC load calculations.
Verify fuel energy assumptions in an engine efficiency or range calculation.

Frequently Asked Questions

Last updated: 2026-07-22 · Reviewed by Nham Vu