Which fuel consumption units are supported?

The converter supports L/100km, mpg US, mpg UK, and km/L.

What is the difference between mpg US and mpg UK?

They use different gallon sizes. An Imperial gallon is larger than a US gallon, so the same vehicle generally has a higher numeric mpg UK value.

Can I convert mpg to L/100km?

Yes. Enter a positive mpg US or mpg UK value, choose L/100km as the output unit, and calculate.

Why are mpg and L/100km reciprocal?

mpg measures distance per gallon, while L/100km measures fuel used per distance. Higher mpg therefore corresponds to lower L/100km.

How many decimal places can I display?

You can choose from 0 to 10 decimal places. The default is 4.

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Fuel Consumption Converter (L/100km / mpg US / mpg UK / km/L)

Convert fuel consumption / fuel economy between L/100km, miles per US gallon (mpg US), miles per Imperial gallon (mpg UK), and km/L. mpg and L/100km are reciprocal (higher mpg = lower L/100km), so conversion goes through the km/L axis, not a single multiplier. Defining constants are exact by law: 1 US gallon = 3.785411784 L (NIST HB 44), 1 Imperial gallon = 4.54609 L (UK W&M Act 1985), 1 mile = 1.609344 km (1959 agreement). Reference: a compact car at ~6 L/100km ≈ 39 mpg US ≈ 47 mpg UK.

Execution

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2 examples

6 L/100km (compact) → mpg US ≈ 39.2024

km/L = 100/6 = 16.6667; mpg US = 16.6667 / 0.425144 = 39.2024. A typical compact car fuel economy.

{"result":"6 L/100km = 39.2024 mpg (US). All units: L/100km=6, mpg (US)=39.2024, mpg (UK)=47.0794, km/L=16.6667.","metadata":{"input":{"inputUnit":"L/100km","value":6,"outputUnit":"mpgUS"},"result":{"outputValue":39.2024,"outputUnit":"mpgUS","L/100km":6,"mpgUS":39.2024,"mpgUK":47.0794,"km/L":16.6667}}}

30 mpg US → L/100km ≈ 7.8405

km/L = 30 × 0.425144 = 12.7543; L/100km = 100/12.7543 = 7.8405. A mid-size sedan fuel economy.

{"result":"30 mpg (US) = 7.8405 L/100km. All units: L/100km=7.8405, mpg (US)=30, mpg (UK)=36.0285, km/L=12.7543.","metadata":{"input":{"inputUnit":"mpgUS","value":30,"outputUnit":"L/100km"},"result":{"outputValue":7.8405,"outputUnit":"L/100km","L/100km":7.8405,"mpgUS":30,"mpgUK":36.0285,"km/L":12.7543}}}

Inputs

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4 options

SettingsAdjust formats, ranges, numbers, and modes.4

Input unitselectOptionalValuenumberRequiredFuel consumption in the selected Input unit. Must be strictly positive.Output unitselectOptionalDecimal PlacesnumberOptional

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Samples

Fuel Consumption Converter (L/100km / mpg US / mpg UK / km/L)

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Examples

1. Convert compact-car consumption to mpg US

2. Convert US fuel economy to L/100km

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