US gallons per 100 miles to miles per US gallon
Type a value in US gallons per 100 miles to see it in miles per US gallon straight away, or type in the second box to convert back.
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How to use it
- Type the value in the US gallons per 100 miles box.
- Read the result in miles per US gallon as you type, and pick the precision you need.
- Swap the direction to convert back, or copy the result.
How it is calculated
mpg (US) = 100 ÷ gal (US)/100 mi
Divide 100 by the value in US gallons per 100 miles, because the two units are reciprocal.
Example
To convert 25 gal (US)/100 mi to miles per US gallon: 100 ÷ 25 = 4 mpg (US).
Conversion table
| US gallons per 100 miles (gal (US)/100 mi) | Miles per US gallon (mpg (US)) |
|---|---|
| 1 | 100 |
| 2 | 50 |
| 3 | 33.3333 |
| 5 | 20 |
| 10 | 10 |
| 20 | 5 |
| 25 | 4 |
| 50 | 2 |
| 100 | 1 |
| 250 | 0.4 |
| 500 | 0.2 |
| 1,000 | 0.1 |
About the units
- US gallon per 100 miles
- US gallons used to travel 100 miles, shown on US fuel economy labels. It equals 100 divided by US mpg.
- Mile per US gallon
- Miles traveled on one US gallon of 3.785411784 liters, the standard in the United States. One mile is exactly 1.609344 km.
Limits and caveats
- Results are rounded for display and computed with the browser's floating point precision (about 15 significant digits).
- Both unit factors are exact by their official definitions.
Questions about this tool
How many miles per US gallon are in one US gallon per 100 miles?
1 gal (US)/100 mi = 100 mpg (US) exactly.
How do I convert US gallons per 100 miles to miles per US gallon?
Use mpg (US) = 100 ÷ gal (US)/100 mi. For example, 25 gal (US)/100 mi = 4 mpg (US).
How many US gallons per 100 miles are in one mile per US gallon?
1 mpg (US) = 100 gal (US)/100 mi.
Why is mpg to L/100 km not a simple multiplication?
The units are reciprocal: one is distance per fuel, the other fuel per distance. You divide about 235.215 by the US mpg value, so 30 mpg is about 7.84 L/100 km.
Why do US and UK mpg differ?
The imperial gallon is 4.54609 L and the US gallon is 3.785411784 L, so the same car shows about 20% more miles per gallon in UK figures.