ConverterFuel Economy Converter
Convert between US miles per gallon and litres per 100 kilometres with the gallon convention visible.
Derives the reciprocal from exact US-gallon and international-mile definitions, rejects the undefined zero case, and labels finite decimal output honestly.
What This Category Covers
- MPG distance-per-fuel values
- L/100km fuel-per-distance values
- Higher-is-better versus lower-is-better interpretation
- U.S. and imperial gallon ambiguity
- Vehicle comparisons rather than trip-cost prediction
Common Use Cases
- MPG on these pages means miles per US liquid gallon.
- Higher US MPG and lower L/100 km indicate lower stated consumption.
- Imperial MPG uses a different gallon and is not silently substituted.
Quick Reference
| Task | Recommended Tool | Why It Helps |
|---|---|---|
| Import car research | MPG to L/100km | Aligns MPG listings with metric consumption values. |
| Metric-to-US comparisons | L/100km to MPG | Translates lower-is-better consumption into higher-is-better mileage. |
| Fleet reporting | MPG to L/100km | Keeps dashboards in a single unit system while preserving source labels. |
MPG Convention And Reciprocal Direction
The two established MPG routes use the US liquid gallon. Imperial MPG uses a different gallon, so an unlabeled regional value should be identified before comparison rather than silently converted under the wrong convention.
US MPG measures distance per fuel quantity, while L/100 km measures fuel quantity per fixed distance. The relationship is reciprocal: higher MPG and lower L/100 km can describe the same more-efficient stated value.
The conversion factor is derived from exact mile and US-gallon definitions but has a repeating decimal expansion. Zero has no reciprocal result, and the conversion does not predict trip cost or real-world vehicle performance.
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Related Guides
These references explain why MPG and L/100km move in opposite directions, why regional fuel-economy reporting differs, and when original source labels should be preserved.
All 2 Tools In This Category
MPG to L/100km
Convert a US-MPG fuel-economy figure into metric fuel consumption. MPG means miles per US liquid gallon on these two established routes; Imperial MPG uses a different gallon.
FuelL/100km to MPG
Convert metric fuel consumption into US miles per gallon. MPG means miles per US liquid gallon on these two established routes; Imperial MPG uses a different gallon.
Related Categories
Fuel Economy Converter FAQ
MPG measures distance per fuel amount, so higher means farther travel. L/100km measures fuel consumed per fixed distance, so lower means less fuel used.
Yes. Keep the source value beside the converted result, especially when comparing regional listings or fleet data.
No. It only changes the unit. Trip cost also depends on distance, fuel price, driving conditions, and load.