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Fuel Efficiency Converter - Btu(IT)/lb to J/kg Calculator

How to Convert Fuel Efficiency

The Fuel Efficiency Converter calculates the equivalent fuel efficiency between British thermal unit (International Table) per pound (Btu(IT)/lb) and joule per kilogram (J/kg) using the following conversion factors:

From Btu(IT)/lb to J/kg:

\( \text{Fuel Efficiency (J/kg)} = \text{Fuel Efficiency (Btu(IT)/lb)} \times 2326 \)

From J/kg to Btu(IT)/lb:

\( \text{Fuel Efficiency (Btu(IT)/lb)} = \text{Fuel Efficiency (J/kg)} \times 0.000429923 \)

Where:

  • \( \text{Btu(IT)/lb} \): British thermal unit (International Table) per pound, a unit of fuel efficiency by mass, commonly used in energy calculations in the US and UK.
  • \( \text{J/kg} \): Joule per kilogram, a metric unit used in scientific and engineering applications to measure energy per unit mass.

Enter the fuel efficiency value and select the unit to convert between Btu(IT)/lb and J/kg.

Using the Fuel Efficiency Converter

This converter is designed to assist with converting fuel efficiency between Btu(IT)/lb and J/kg, useful in fields like thermodynamics, energy engineering, and HVAC systems.

Input the fuel efficiency value and select the unit (Btu(IT)/lb or J/kg). The calculator will display the converted values in both units.

Example: Convert 4 Btu(IT)/lb to J/kg.


  1. Fuel Efficiency: \( 4 \, \text{Btu(IT)/lb} \)
  2. Conversion: \( 4 \times 2326 = 9304 \, \text{J/kg} \)
  3. Result: \( 4 \, \text{Btu(IT)/lb} = 9304 \, \text{J/kg} \)

Use this tool for quick and accurate conversions in scientific and engineering applications.

Common Conversion Table

The following table provides quick reference conversions for common fuel efficiency values between Btu(IT)/lb and J/kg:

Btu(IT)/lb J/kg
1 2326
2 4652
5 11630
10 23260
20 46520

Use this table for quick lookups or to verify calculator results.

Common FAQ

Below are frequently asked questions about fuel efficiency conversions between Btu(IT)/lb and J/kg:

  • Q: What is the difference between Btu(IT)/lb and J/kg?
    A: Btu(IT)/lb (British thermal unit per pound) measures energy per pound, while J/kg (joule per kilogram) measures energy per kilogram. 1 Btu(IT)/lb equals 2326 J/kg due to unit scaling (1 lb ≈ 0.453592 kg).
  • Q: Why convert between Btu(IT)/lb and J/kg?
    A: Conversions are needed in industries like HVAC and energy engineering, where Btu(IT)/lb is common in the US/UK, and J/kg is used in metric systems globally.
  • Q: How accurate is this converter?
    A: The converter uses the precise conversion factor (1 Btu(IT)/lb = 2326 J/kg) and provides results rounded to 6 decimal places for Btu(IT)/lb and 5 for J/kg, ensuring high accuracy.
  • Q: Can negative values be converted?
    A: Yes, the converter handles negative values, which may be relevant in specific scientific contexts, and performs conversions accurately.
  • Q: How does Btu(IT)/lb differ from other Btu definitions?
    A: Btu(IT) (International Table) is slightly different from Btu(th) (thermochemical). 1 Btu(IT)/lb = 2326 J/kg, while 1 Btu(th)/lb ≈ 2324.444 J/kg, due to different Btu definitions.
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