Unit converter

Fuel Efficiency - Mass converter

Convert energy-per-mass units including joules per kilogram, calories per gram, and BTU per pound.

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1 J/kg = 0.001 kJ/kg

All Fuel Efficiency - Mass units

From 1 J/kg
UnitValue
Joule/kilogram J/kg 1
Kilojoule/kilogram kJ/kg 0.001
Calorie/gram cal/g 0.0002388459
Kilocalorie/kilogram kcal/kg 0.0002388459
Btu/pound Btu/lb 0.0004299226
Btu/kilogram Btu/kg 0.0009478134
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Common tasks

Joule/kilogram to Kilojoule/kilogramJ/kg to kJ/kg Kilojoule/kilogram to Joule/kilogramkJ/kg to J/kg Joule/kilogram to Calorie/gramJ/kg to cal/g Calorie/gram to Joule/kilogramcal/g to J/kg Joule/kilogram to Kilocalorie/kilogramJ/kg to kcal/kg Kilocalorie/kilogram to Joule/kilogramkcal/kg to J/kg

Reference

How fuel efficiency - mass conversion works

Mass-based fuel energy density compares available energy with fuel mass. Values are normalized to Joule/kilogram before conversion to the requested output unit.

Values are converted to joule/kilogram first, then from that reference into the requested unit. Keeping a single documented reference reduces inconsistent pair-by-pair constants.

Accuracy note: SI relationships follow the cited reference. Conventional and domain-specific factors use the established ConvertWin factor inventory; verify safety-critical work against the governing standard.

Unit reference

UnitSymbol1 unit in J/kg
Joule/kilogramJ/kg1
Kilojoule/kilogramkJ/kg1,000
Calorie/gramcal/g4,186.8
Kilocalorie/kilogramkcal/kg4,186.8
Btu/poundBtu/lb2,326
Btu/kilogramBtu/kg1,055.06

Long-tail directory

Every indexed conversion

Choose a source unit to see all available destinations.

From Joule/kilogram (J/kg)
Joule/kilogram to Kilojoule/kilogramJoule/kilogram to Calorie/gramJoule/kilogram to Kilocalorie/kilogramJoule/kilogram to Btu/pound
From Kilojoule/kilogram (kJ/kg)
Kilojoule/kilogram to Joule/kilogramKilojoule/kilogram to Calorie/gramKilojoule/kilogram to Kilocalorie/kilogramKilojoule/kilogram to Btu/pound
From Calorie/gram (cal/g)
Calorie/gram to Joule/kilogramCalorie/gram to Kilojoule/kilogramCalorie/gram to Kilocalorie/kilogramCalorie/gram to Btu/pound
From Kilocalorie/kilogram (kcal/kg)
Kilocalorie/kilogram to Joule/kilogramKilocalorie/kilogram to Kilojoule/kilogramKilocalorie/kilogram to Calorie/gramKilocalorie/kilogram to Btu/pound
From Btu/pound (Btu/lb)
Btu/pound to Joule/kilogramBtu/pound to Kilojoule/kilogramBtu/pound to Calorie/gramBtu/pound to Kilocalorie/kilogram

Primary source

Definitions and standards

The SI framework is checked against NIST Guide for the Use of the International System of Units. Conventional factors are retained from the extended ConvertWin inventory and carry the accuracy note shown above.

See Methods & sources for rounding rules, exact-value handling, and review policy.

Questions

Fuel Efficiency - Mass FAQ

What is the reference unit for fuel efficiency - mass conversions?

ConvertWin uses joule/kilogram (J/kg) as the internal reference for this category, then converts to the selected output unit.

How accurate is this fuel efficiency - mass converter?

SI relationships follow the cited reference. Conventional and domain-specific factors use the established ConvertWin factor inventory; verify safety-critical work against the governing standard.