21 Kilometer/Gallon (US) to Miles/Gallon (UK)
Quick answer
21 Kilometer/Gallon (US) (km/gal) equals
15.670956 mpg (UK)
To convert 21 Kilometer/Gallon (US)s to Miles/Gallon (UK)s, multiply by 0.7462359936. Therefore, 21 Kilometer/Gallon (US) (km/gal) equals 15.670956 Miles/Gallon (UK) (mpg (UK)).
Formula: mpg (UK) = km/gal × 0.7462359936. Calculation: 21 × 0.7462359936 = 15.670956 mpg (UK).
Convert Kilometer/Gallon (US) (km/gal) to Miles/Gallon (UK) (mpg (UK)) online with our free unit converter. In fuel economy, 1 km/gal = 0.746236 mpg (UK). Explore step-by-step conversion steps, mathematical formulas, and quick conversion reference tables below.
Worked example: converting Kilometer/Gallon (US) to Miles/Gallon (UK)
- Step 1 — start with the formula. mpg (UK) = km/gal × 0.7462359936
- Step 2 — substitute your figure. 21 km/gal × 0.7462359936
- Step 3 — read the result. 21 km/gal = 15.670956 mpg (UK)
- Step 4 — check it in reverse. km/gal = mpg (UK) × 1.3400586524 returns 21 km/gal, which matches the figure you started with.
Fuel Economy Converter
11 units available
21 km/gal = 15.670956 mpg (UK)
Formula:
mpg (UK) = km/gal × 0.7462359936With your value: 21 km/gal = 15.67095587 mpg (UK)
Other Kilometer/Gallon (US) to Miles/Gallon (UK) conversions
Kilometer/Gallon (US) to Miles/Gallon (UK) Conversion Table
| Kilometer/Gallon (US) (km/gal) | Miles/Gallon (UK) (mpg (UK)) |
|---|---|
| 0.5 | 0.373118 |
| 1 | 0.746236 |
| 2 | 1.492472 |
| 5 | 3.73118 |
| 10 | 7.46236 |
| 15 | 11.19354 |
| 20 | 14.92472 |
| 25 | 18.6559 |
| 50 | 37.3118 |
| 100 | 74.623599 |
| 250 | 186.558998 |
| 500 | 373.117997 |
| 1000 | 746.235994 |
Miles/Gallon (UK) to Kilometer/Gallon (US) Conversion Table
| Miles/Gallon (UK) (mpg (UK)) | Kilometer/Gallon (US) (km/gal) |
|---|---|
| 0.5 | 0.670029 |
| 1 | 1.340059 |
| 2 | 2.680117 |
| 5 | 6.700293 |
| 10 | 13.400587 |
| 15 | 20.10088 |
| 20 | 26.801173 |
| 25 | 33.501466 |
| 50 | 67.002933 |
| 100 | 134.005865 |
| 250 | 335.014663 |
| 500 | 670.029326 |
| 1000 | 1,340.058652 |
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.
Kilometer/Gallon (US) (km/gal)
Fuel Economy
Composite of a defined volume and a defined length. US and imperial gallons differ, so mpg figures are not interchangeable between them.
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
Miles/Gallon (UK) (mpg (UK))
Fuel Economy
Composite of a defined volume and a defined length. US and imperial gallons differ, so mpg figures are not interchangeable between them.
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 Kilometer/Gallon (US) to Miles/Gallon (UK)
To convert from Kilometer/Gallon (US) (km/gal) to Miles/Gallon (UK) (mpg (UK)), multiply the value by 0.7462359936.
Formula: mpg (UK) = km/gal × 0.7462359936
Reverse: km/gal = mpg (UK) × 1.3400586524
Step-by-Step Example
- Start with your value in Kilometer/Gallon (US). For example: 5 km/gal
- Multiply by the conversion factor: 5 x 0.7462359936
- The result is: 3.73118 mpg (UK)
Kilometer/Gallon (US) and Miles/Gallon (UK) Relationship
This calculation facilitates standardized conversion between recognized units of fuel economy. Since 1 Kilometer/Gallon (US) represents a fraction of a Miles/Gallon (UK) (1 Miles/Gallon (UK) ≈ 1.3401 Kilometer/Gallon (US)s), the Miles/Gallon (UK) is the larger measurement interval. Understanding the relationship between Kilometer/Gallon (US) and Miles/Gallon (UK) is essential for accurate calculations in physics, engineering, commerce, and daily applications.
About Kilometer/Gallon (US)
The Kilometer/Gallon (US) (symbol: km/gal) is a recognized unit in the US Customary / Imperial measurement framework, utilized within fuel economy applications for precision and standardized data representation.
Common uses of Kilometer/Gallon (US): fuel economy calculations, engineering and science, education.
About Miles/Gallon (UK)
The Miles/Gallon (UK) (symbol: mpg (UK)) is a recognized unit in the Standard measurement framework, utilized within fuel economy applications for precision and standardized data representation.
Common uses of Miles/Gallon (UK): fuel economy calculations, engineering and science, education.
Frequently Asked Questions
- What is 21 Kilometer/Gallon (US) in Miles/Gallon (UK)?
- 21 Kilometer/Gallon (US) equals 15.670956 Miles/Gallon (UK).
- How many Miles/Gallon (UK)s are in 1 Kilometer/Gallon (US)?
- There are exactly 0.7462359936 Miles/Gallon (UK)s in 1 Kilometer/Gallon (US). This means the conversion factor from Kilometer/Gallon (US) to Miles/Gallon (UK) is 0.7462359936.
- What is the formula to convert Kilometer/Gallon (US) to Miles/Gallon (UK)?
- The formula to convert Kilometer/Gallon (US) to Miles/Gallon (UK) is: mpg (UK) = km/gal × 0.7462359936. For example, to convert 10 Kilometer/Gallon (US)s to Miles/Gallon (UK)s, you would multiply 10 by 0.7462359936.
- What is a Kilometer/Gallon (US)?
- The Kilometer/Gallon (US) (symbol: km/gal) is a recognized unit in the US Customary / Imperial measurement framework, utilized within fuel economy applications for precision and standardized data representation.
- What is a Miles/Gallon (UK)?
- The Miles/Gallon (UK) (symbol: mpg (UK)) is a recognized unit in the Standard measurement framework, utilized within fuel economy applications for precision and standardized data representation.
- What are the common uses of Kilometer/Gallon (US)?
- The Kilometer/Gallon (US) is commonly used in fuel economy calculations, engineering and science, education.
Related Fuel Economy Conversions
Cite this page
UnitConvertLab. (2026). 21 Kilometer/Gallon (US) to Miles/Gallon (UK). UnitConvertLab. Retrieved from https://unitconvertlab.com/convert/21-km_per_gallon_us-to-mpg_uk