Convert Calories per Gram to Joules per Kilogram
Instantly convert Calories per Gram (cal/g) to Joules per Kilogram (J/kg) with our free online calculator.
Formula: cal/g to J/kg — multiply by 4184
Reference Table
| Calories per Gram (cal/g) | Joules per Kilogram (J/kg) |
|---|---|
| 1 | 4184 |
| 5 | 20920 |
| 10 | 41840 |
| 25 | 104600 |
| 50 | 209200 |
| 100 | 418400 |
How to Convert Calories per Gram to Joules per Kilogram
Formula
To convert Calories per Gram (cal/g) to Joules per Kilogram (J/kg): multiply by 4184
Step-by-Step
- Start with your value in Calories per Gram (cal/g).
- Multiply by 4184 to perform the conversion.
- The result is your value expressed in Joules per Kilogram (J/kg).
Conversion Factor
1 cal/g = 4184 J/kg
Reverse Factor
1 J/kg = 0.000239006 cal/g
Worked Example
Convert 25 Calories per Gram to Joules per Kilogram: 25 cal/g = 104600 J/kg
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.
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.
Quick Facts
- 1 Calorie per Gram equals 4184 Joules per Kilogram
- 1 Joule per Kilogram equals 0.000239006 Calories per Gram
- Calorie per Gram is a unit of specific energy
- Joule per Kilogram is a unit of specific energy
- This conversion is commonly used in fuel comparison, battery technology, and rocket propulsion
- The Calorie per Gram belongs to the metric system
Common Calorie per Gram to Joule per Kilogram Conversions
| Calories per Gram (cal/g) | Joules per Kilogram (J/kg) |
|---|---|
| 0.01 | 41.84 |
| 0.1 | 418.4 |
| 0.25 | 1046 |
| 0.5 | 2092 |
| 1 | 4184 |
| 2 | 8368 |
| 3 | 12552 |
| 5 | 20920 |
| 10 | 41840 |
| 15 | 62760 |
| 20 | 83680 |
| 25 | 104600 |
| 50 | 209200 |
| 75 | 313800 |
| 100 | 418400 |
| 250 | 1046000 |
| 500 | 2092000 |
| 1000 | 4184000 |
| 5000 | 20920000 |
| 10000 | 41840000 |
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.
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.
Why Convert Calories per Gram to Joules per Kilogram?
Converting between Calories per Gram and Joules per Kilogram 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 Calories per Gram to Joules per Kilogram?
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. To convert Calories per Gram to Joules per Kilogram, multiply by 4184. For example, 25 cal/g equals 104600 J/kg.
How many Joules per Kilogram are in 1 Calorie per Gram?
There are 4184 Joules per Kilogram in 1 Calorie per Gram.
How many Calories per Gram are in 1 Joule per Kilogram?
There are 0.000239006 Calories per Gram in 1 Joule per Kilogram.
What is the formula for Calorie per Gram to Joule per Kilogram conversion?
The formula is: multiply by 4184. This means 1 cal/g = 4184 J/kg.
Is a Calorie per Gram bigger than a Joule per Kilogram?
No. One Calorie per Gram is smaller than one Joule per Kilogram because 1 cal/g equals 4184 J/kg, which is greater than 1.
When do you need to convert between Calories per Gram and Joules per Kilogram?
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. Calorie per Gram and Joule per Kilogram 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.