21 Joule/Second to Horsepower (Mech)
Quick answer
21 Joule/Second (J/s) equals
0.028161 hp
To convert 21 Joule/Seconds to Horsepower (Mech)s, multiply by 0.0013410221. Therefore, 21 Joule/Second (J/s) equals 0.028161 Horsepower (Mech) (hp).
Formula: hp = J/s × 0.0013410221. Calculation: 21 × 0.0013410221 = 0.028161 hp.
Convert Joule/Second (J/s) to Horsepower (Mech) (hp) online with our free unit converter. In power, 1 J/s = 0.001341 hp. Explore step-by-step conversion steps, mathematical formulas, and quick conversion reference tables below.
Worked example: converting Joule/Second to Horsepower (Mech)
- Step 1 — start with the formula. hp = J/s × 0.0013410221
- Step 2 — substitute your figure. 21 J/s × 0.0013410221
- Step 3 — read the result. 21 J/s = 0.028161 hp
- Step 4 — check it in reverse. J/s = hp × 745.6998715823 returns 20.9997 J/s, which matches the figure you started with.
Power Converter
22 units available
21 J/s = 0.028161 hp
Formula:
hp = J/s × 0.0013410221With your value: 21 J/s = 0.02816146 hp
How big is that?
Everyday references on a logarithmic scale, all expressed in joule/second so you can sanity-check the result.
Other Joule/Second to Horsepower (Mech) conversions
Joule/Second to Horsepower (Mech) Conversion Table
| Joule/Second (J/s) | Horsepower (Mech) (hp) |
|---|---|
| 0.5 | 0.000671 |
| 1 | 0.001341 |
| 2 | 0.002682 |
| 5 | 0.006705 |
| 10 | 0.01341 |
| 15 | 0.020115 |
| 20 | 0.02682 |
| 25 | 0.033526 |
| 50 | 0.067051 |
| 100 | 0.134102 |
| 250 | 0.335256 |
| 500 | 0.670511 |
| 1000 | 1.341022 |
Horsepower (Mech) to Joule/Second Conversion Table
| Horsepower (Mech) (hp) | Joule/Second (J/s) |
|---|---|
| 0.5 | 372.849936 |
| 1 | 745.699872 |
| 2 | 1,491.399743 |
| 5 | 3,728.499358 |
| 10 | 7,456.998716 |
| 15 | 11,185.498074 |
| 20 | 14,913.997432 |
| 25 | 18,642.49679 |
| 50 | 37,284.993579 |
| 100 | 74,569.987158 |
| 250 | 186,424.967896 |
| 500 | 372,849.935791 |
| 1000 | 745,699.871582 |
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.
Joule/Second (J/s)
Power
Derived from the watt (1 W = 1 J/s).
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
Horsepower (Mech) (hp)
Power
Mechanical horsepower is exactly 550 ft·lbf/s = 745.699 871 582 270 22 W.
Metric horsepower (PS) is 735.498 75 W — about 1.4 % lower.
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
How to Convert Joule/Second to Horsepower (Mech)
To convert from Joule/Second (J/s) to Horsepower (Mech) (hp), multiply the value by 0.0013410221.
Formula: hp = J/s × 0.0013410221
Reverse: J/s = hp × 745.6998715823
Step-by-Step Example
- Start with your value in Joule/Second. For example: 5 J/s
- Multiply by the conversion factor: 5 x 0.0013410221
- The result is: 0.006705 hp
Joule/Second and Horsepower (Mech) Relationship
This calculation facilitates standardized conversion between recognized units of power. Since 1 Joule/Second represents a fraction of a Horsepower (Mech) (1 Horsepower (Mech) ≈ 745.6999 Joule/Seconds), the Horsepower (Mech) is the larger measurement interval. Understanding the relationship between Joule/Second and Horsepower (Mech) is essential for accurate calculations in physics, engineering, commerce, and daily applications.
About Joule/Second
The Joule/Second (symbol: J/s) is a recognized unit in the Metric (SI) measurement framework, utilized within power applications for precision and standardized data representation.
Common uses of Joule/Second: power calculations, engineering and science, education.
About Horsepower (Mech)
The Horsepower (Mech) (symbol: hp) is a recognized unit in the Standard measurement framework, utilized within power applications for precision and standardized data representation.
Common uses of Horsepower (Mech): power calculations, engineering and science, education.
Frequently Asked Questions
- What is 21 Joule/Second in Horsepower (Mech)?
- 21 Joule/Second equals 0.028161 Horsepower (Mech).
- How many Horsepower (Mech)s are in 1 Joule/Second?
- There are exactly 0.0013410221 Horsepower (Mech)s in 1 Joule/Second. This means the conversion factor from Joule/Second to Horsepower (Mech) is 0.0013410221.
- What is the formula to convert Joule/Second to Horsepower (Mech)?
- The formula to convert Joule/Second to Horsepower (Mech) is: hp = J/s × 0.0013410221. For example, to convert 10 Joule/Seconds to Horsepower (Mech)s, you would multiply 10 by 0.0013410221.
- What is a Joule/Second?
- The Joule/Second (symbol: J/s) is a recognized unit in the Metric (SI) measurement framework, utilized within power applications for precision and standardized data representation.
- What is a Horsepower (Mech)?
- The Horsepower (Mech) (symbol: hp) is a recognized unit in the Standard measurement framework, utilized within power applications for precision and standardized data representation.
- What are the common uses of Joule/Second?
- The Joule/Second is commonly used in power calculations, engineering and science, education.
Related Power Conversions
Cite this page
UnitConvertLab. (2026). 21 Joule/Second to Horsepower (Mech). UnitConvertLab. Retrieved from https://unitconvertlab.com/convert/21-joule_per_second-to-horsepower_mech