Convert Joules per Kilogram to Calories per Gram
Instantly convert Joules per Kilogram (J/kg) to Calories per Gram (cal/g) with our free online calculator.
Formula: J/kg to cal/g — multiply by 2.3901e-4
Reference Table
| Joules per Kilogram (J/kg) | Calories per Gram (cal/g) |
|---|---|
| 1 | 0.000239006 |
| 5 | 0.00119503 |
| 10 | 0.00239006 |
| 25 | 0.00597514 |
| 50 | 0.0119503 |
| 100 | 0.0239006 |
How to Convert Joules per Kilogram to Calories per Gram
Formula
To convert Joules per Kilogram (J/kg) to Calories per Gram (cal/g): multiply by 2.3901e-4
Step-by-Step
- Start with your value in Joules per Kilogram (J/kg).
- Multiply by 2.3901e-4 to perform the conversion.
- The result is your value expressed in Calories per Gram (cal/g).
Conversion Factor
1 J/kg = 0.000239006 cal/g
Reverse Factor
1 cal/g = 4184 J/kg
Worked Example
Convert 25 Joules per Kilogram to Calories per Gram: 25 J/kg = 0.00597514 cal/g
About Joule per Kilogram (J/kg)
The SI unit of specific energy (energy per unit mass) per ISO 80000-5 §5-15 — used for gravimetric energy density of fuels, batteries, explosives, and propellants. J/kg is the universal unit for cross-technology energy-storage comparisons, and the natural unit for kinetic-energy-per-mass (E_k/m = ½v² in J/kg = m²/s²). Reference values for energy-storage media per Sandia National Labs / DOE battery testing protocols and NFPA 921 fire-investigation reference data: lithium-ion 18650 cell ~550,000 J/kg (gravimetric); lithium-iron-phosphate (LFP, LiFePO₄) cells 360,000-450,000 J/kg; lead-acid battery 110,000-180,000 J/kg; gasoline 46,400,000 J/kg lower heating value (LHV) per ASTM D4868; diesel 45,500,000 J/kg LHV; coal (bituminous) ~24,000,000 J/kg; TNT 4,184,000 J/kg (the explosive-yield reference standard, basis of 'megaton' nuclear yield); hydrogen H₂ gas 120,000,000 J/kg LHV (highest gravimetric of any chemical fuel); jet fuel Jet-A 43,150,000 J/kg per ASTM D1655. Specific energy is also the key metric for compressed-air storage (CAES), pumped-hydro per-mass equivalent (gh = 9.81·h J/kg), and projectile kinetic energy per unit mass.
About Calorie per Gram (cal/g)
A CGS specific-energy unit equal to exactly 4,184 J/kg (using the thermochemical calorie definition per NIST SP 811), numerically identical to kcal/kg. cal/g is the working unit for chemistry reaction enthalpies per unit mass (heats of combustion measured in bomb calorimeters per ASTM D240 / D5865), food science nutritional energy (1 dietary 'Calorie' = 1 kcal = 1,000 cal — a confusing convention that persists despite ISO 80000-5 deprecation), thermochemistry per the NIST WebBook and Linstrom-Mallard NIST Standard Reference Database 69, and DSC (Differential Scanning Calorimetry) integration output for biological and pharmaceutical samples (TA Instruments, Mettler Toledo, PerkinElmer instruments default to cal/g for some legacy methods). Reference values per Atkins Physical Chemistry: water heat of vaporization at 100°C ≈ 540 cal/g; ice heat of fusion ≈ 80 cal/g; sucrose heat of combustion ≈ 3,940 cal/g; protein heat of combustion ≈ 4,100 cal/g; fats/oils ≈ 9,200 cal/g (the basis of the '9 calories per gram' nutritional rule of thumb for fat). Food labels outside the US showing 'kcal per 100g' display this unit scaled to a 100-gram serving size.
Quick Facts
- 1 Joule per Kilogram equals 0.000239006 Calories per Gram
- 1 Calorie per Gram equals 4184 Joules per Kilogram
- Joule per Kilogram is a unit of specific energy
- Calorie per Gram is a unit of specific energy
- This conversion is commonly used in fuel comparison, battery technology, and rocket propulsion
- The Joule per Kilogram belongs to the metric system
Common Joule per Kilogram to Calorie per Gram Conversions
| Joules per Kilogram (J/kg) | Calories per Gram (cal/g) |
|---|---|
| 0.01 | 0.00000239006 |
| 0.1 | 0.0000239006 |
| 0.25 | 0.0000597514 |
| 0.5 | 0.000119503 |
| 1 | 0.000239006 |
| 2 | 0.000478011 |
| 3 | 0.000717017 |
| 5 | 0.00119503 |
| 10 | 0.00239006 |
| 15 | 0.00358509 |
| 20 | 0.00478011 |
| 25 | 0.00597514 |
| 50 | 0.0119503 |
| 75 | 0.0179254 |
| 100 | 0.0239006 |
| 250 | 0.0597514 |
| 500 | 0.119503 |
| 1000 | 0.239006 |
| 5000 | 1.19503 |
| 10000 | 2.39006 |
Understanding Joules per Kilogram
The Joule per Kilogram (symbol: J/kg) is a unit of specific energy. The SI unit of specific energy (energy per unit mass) per ISO 80000-5 §5-15 — used for gravimetric energy density of fuels, batteries, explosives, and propellants. J/kg is the universal unit for cross-technology energy-storage comparisons, and the natural unit for kinetic-energy-per-mass (E_k/m = ½v² in J/kg = m²/s²). Reference values for energy-storage media per Sandia National Labs / DOE battery testing protocols and NFPA 921 fire-investigation reference data: lithium-ion 18650 cell ~550,000 J/kg (gravimetric); lithium-iron-phosphate (LFP, LiFePO₄) cells 360,000-450,000 J/kg; lead-acid battery 110,000-180,000 J/kg; gasoline 46,400,000 J/kg lower heating value (LHV) per ASTM D4868; diesel 45,500,000 J/kg LHV; coal (bituminous) ~24,000,000 J/kg; TNT 4,184,000 J/kg (the explosive-yield reference standard, basis of 'megaton' nuclear yield); hydrogen H₂ gas 120,000,000 J/kg LHV (highest gravimetric of any chemical fuel); jet fuel Jet-A 43,150,000 J/kg per ASTM D1655. Specific energy is also the key metric for compressed-air storage (CAES), pumped-hydro per-mass equivalent (gh = 9.81·h J/kg), and projectile kinetic energy per unit mass.
It belongs to the metric measurement system.
Joules per Kilogram are commonly used in fuel comparison, battery technology, and rocket propulsion.
Understanding Calories per Gram
The Calorie per Gram (symbol: cal/g) is a unit of specific energy. A CGS specific-energy unit equal to exactly 4,184 J/kg (using the thermochemical calorie definition per NIST SP 811), numerically identical to kcal/kg. cal/g is the working unit for chemistry reaction enthalpies per unit mass (heats of combustion measured in bomb calorimeters per ASTM D240 / D5865), food science nutritional energy (1 dietary 'Calorie' = 1 kcal = 1,000 cal — a confusing convention that persists despite ISO 80000-5 deprecation), thermochemistry per the NIST WebBook and Linstrom-Mallard NIST Standard Reference Database 69, and DSC (Differential Scanning Calorimetry) integration output for biological and pharmaceutical samples (TA Instruments, Mettler Toledo, PerkinElmer instruments default to cal/g for some legacy methods). Reference values per Atkins Physical Chemistry: water heat of vaporization at 100°C ≈ 540 cal/g; ice heat of fusion ≈ 80 cal/g; sucrose heat of combustion ≈ 3,940 cal/g; protein heat of combustion ≈ 4,100 cal/g; fats/oils ≈ 9,200 cal/g (the basis of the '9 calories per gram' nutritional rule of thumb for fat). Food labels outside the US showing 'kcal per 100g' display this unit scaled to a 100-gram serving size.
It belongs to the metric measurement system.
Calories per Gram are commonly used in fuel comparison, battery technology, and rocket propulsion.
Why Convert Joules per Kilogram to Calories per Gram?
Converting between Joules per Kilogram and Calories per Gram is a frequent requirement for engineers, scientists, and students working with specific energy values. Different industries and regions favour different unit systems, so having a dependable conversion tool saves time and prevents errors in technical calculations. Whether you are verifying a specification sheet, cross-checking simulation results, or preparing a report for an international audience, accurate specific energy conversion is essential.
Frequently Asked Questions
How do I convert Joules per Kilogram to Calories per Gram?
The SI unit of specific energy (energy per unit mass) per ISO 80000-5 §5-15 — used for gravimetric energy density of fuels, batteries, explosives, and propellants. To convert Joules per Kilogram to Calories per Gram, multiply by 2.3901e-4. For example, 25 J/kg equals 0.00597514 cal/g.
How many Calories per Gram are in 1 Joule per Kilogram?
There are 0.000239006 Calories per Gram in 1 Joule per Kilogram.
How many Joules per Kilogram are in 1 Calorie per Gram?
There are 4184 Joules per Kilogram in 1 Calorie per Gram.
What is the formula for Joule per Kilogram to Calorie per Gram conversion?
The formula is: multiply by 2.3901e-4. This means 1 J/kg = 0.000239006 cal/g.
Is a Joule per Kilogram bigger than a Calorie per Gram?
Yes. One Joule per Kilogram is larger than one Calorie per Gram because 1 J/kg equals 0.000239006 cal/g, which is less than 1.
When do you need to convert between Joules per Kilogram and Calories per Gram?
A CGS specific-energy unit equal to exactly 4,184 J/kg (using the thermochemical calorie definition per NIST SP 811), numerically identical to kcal/kg. Joule per Kilogram and Calorie per Gram are both specific energy units, so conversion comes up whenever one source of information uses one unit and another uses the other — a classic cross-reference challenge in engineering, trade, travel, and everyday life.