21 Calorie (th) to Joule
Quick answer
21 Calorie (th) (cal) equals
87.864 J
To convert 21 Calorie (th)s to Joules, multiply by 4.184. Therefore, 21 Calorie (th) (cal) equals 87.864 Joule (J).
Formula: J = cal × 4.184. Calculation: 21 × 4.184 = 87.864 J.
Convert Calorie (th) (cal) to Joule (J) online with our free unit converter. In energy, 1 cal = 4.184 J. Explore step-by-step conversion steps, mathematical formulas, and quick conversion reference tables below.
Worked example: converting Calorie (th) to Joule
- Step 1 — start with the formula. J = cal × 4.184
- Step 2 — substitute your figure. 21 cal × 4.184
- Step 3 — read the result. 21 cal = 87.864 J
- Step 4 — check it in reverse. cal = J × 0.2390057361 returns 21 cal, which matches the figure you started with.
Energy Converter
27 units available
21 cal = 87.864 J
Formula:
J = cal × 4.184With your value: 21 cal = 87.864 J
How big is that?
Everyday references on a logarithmic scale, all expressed in calorie (th) so you can sanity-check the result.
Other Calorie (th) to Joule conversions
Calorie (th) to Joule Conversion Table
| Calorie (th) (cal) | Joule (J) |
|---|---|
| 0.5 | 2.092 |
| 1 | 4.184 |
| 2 | 8.368 |
| 5 | 20.92 |
| 10 | 41.84 |
| 15 | 62.76 |
| 20 | 83.68 |
| 25 | 104.6 |
| 50 | 209.2 |
| 100 | 418.4 |
| 250 | 1,046 |
| 500 | 2,092 |
| 1000 | 4,184 |
Joule to Calorie (th) Conversion Table
| Joule (J) | Calorie (th) (cal) |
|---|---|
| 0.5 | 0.119503 |
| 1 | 0.239006 |
| 2 | 0.478011 |
| 5 | 1.195029 |
| 10 | 2.390057 |
| 15 | 3.585086 |
| 20 | 4.780115 |
| 25 | 5.975143 |
| 50 | 11.950287 |
| 100 | 23.900574 |
| 250 | 59.751434 |
| 500 | 119.502868 |
| 1000 | 239.005736 |
Where these values come from
Every factor on this page is traced to the document that defines it. See the full provenance dataset or our methodology.
Calorie (th) (cal)
Energy
The thermochemical calorie is exactly 4.184 J.
The International Table calorie (4.1868 J) and the 15 °C calorie differ slightly.
Source: NIST Special Publication 811, Guide for the Use of the International System of Units
National Institute of Standards and Technology (US) · Reviewed 2026-07-01
Joule (J)
Energy
Derived from the joule (1 J = 1 kg·m²/s²). Thermochemical and IT calories, BTU and kWh are exact defined multiples.
Source: NIST Special Publication 811, Guide for the Use of the International System of Units
National Institute of Standards and Technology (US) · Reviewed 2026-07-01
Standards and context behind Calorie (th) to Joule
- Thermochemical calorie
- Exactly 4.184 J.
- International Table calorie
- 4.1868 J — a slightly different definition still used in steam tables.
- Food Calorie (kcal)
- Nutrition labels' capital-C Calorie is 1,000 small calories.
How to Convert Calorie (th) to Joule
To convert from Calorie (th) (cal) to Joule (J), multiply the value by 4.184.
Formula: J = cal × 4.184
Reverse: cal = J × 0.2390057361
Step-by-Step Example
- Start with your value in Calorie (th). For example: 5 cal
- Multiply by the conversion factor: 5 x 4.184
- The result is: 20.92 J
Calorie (th) and Joule Relationship
This calculation facilitates standardized conversion between recognized units of energy. Since 1 Calorie (th) equals approximately 4.184 Joules, the Calorie (th) represents a larger unit interval than the Joule. Understanding the relationship between Calorie (th) and Joule is essential for accurate calculations in physics, engineering, commerce, and daily applications.
About Calorie (th)
The thermochemical calorie equals 4.184 joules. Not to be confused with the food Calorie (kcal), which equals 1,000 calories.
Common uses of Calorie (th): chemistry, nutrition, heating.
About Joule
The joule is the SI unit of energy. One joule equals the work done when a force of one newton moves an object one meter.
Common uses of Joule: physics, electrical engineering, chemistry.
Frequently Asked Questions
- What is 21 Calorie (th) in Joule?
- 21 Calorie (th) equals 87.864 Joule.
- How many Joules are in 1 Calorie (th)?
- There are exactly 4.184 Joules in 1 Calorie (th). This means the conversion factor from Calorie (th) to Joule is 4.184.
- What is the formula to convert Calorie (th) to Joule?
- The formula to convert Calorie (th) to Joule is: J = cal × 4.184. For example, to convert 10 Calorie (th)s to Joules, you would multiply 10 by 4.184.
- What is a Calorie (th)?
- The thermochemical calorie equals 4.184 joules. Not to be confused with the food Calorie (kcal), which equals 1,000 calories.
- What is a Joule?
- The joule is the SI unit of energy. One joule equals the work done when a force of one newton moves an object one meter.
- What are the common uses of Calorie (th)?
- The Calorie (th) is commonly used in chemistry, nutrition, heating.
- Is a food Calorie a kilocalorie?
- Yes. One dietary Calorie equals 1 kcal = 4,184 joules.
Related Energy Conversions
Cite this page
UnitConvertLab. (2026). 21 Calorie (th) to Joule. UnitConvertLab. Retrieved from https://unitconvertlab.com/convert/21-calorie-to-joule