What’s the difference between US mpg and UK mpg?

Fuel Cost Calculator

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Efficiency unitsDistance (one way)Fuel efficiencyFuel pricePer gallon or per litre, matching the units abovePeople in the carTripCurrency

What the same trip costs if pump prices move, handy when you’re budgeting a drive weeks ahead.
Fuel price	Rate	Trip cost	Per person
-20%	$2.760 / gal	$27.60	$13.80
-10%	$3.105 / gal	$31.05	$15.53
Today’s price	$3.450 / gal	$34.50	$17.25
+10%	$3.795 / gal	$37.95	$18.98
+20%	$4.140 / gal	$41.40	$20.70

How it works

Fuel Cost Calculator in MPG, L/100km or km/L

Enter the distance, your car’s efficiency and the pump price to see what the drive costs, how much fuel you need, and each passenger’s share.

What this does

US mpg, imperial mpg, L/100 km or km per litre, matched to how the pump price is quoted
One-way or round-trip distance, and the cost split evenly across the car
Fuel needed in both gallons and litres, plus cost per mile and per kilometre
Table of the same trip at pump prices 10% and 20% either side of today’s

FAQ

The gallon. A US gallon is 3.785 litres, an imperial gallon is 4.546 litres, so the same car scores about 20% higher in UK mpg than in US mpg. Picking the wrong one is the quickest way to a badly wrong answer here, so match the setting to wherever the efficiency figure came from.

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