How Many Miles Will a Gallon of Gas Get You?

The average new vehicle sold in the United States gets about 27 miles per gallon, according to the EPA's Automotive Trends Report, and the average of everything actually on the road is a little lower, around 24. Small cars and sedans get 30 to 40, compact SUVs 25 to 33, large SUVs and pickups 17 to 23, and hybrids 45 to 57. So one gallon of gas takes most cars 25 to 35 miles.

Those are combined figures, blending city and highway. In town, with stops and cold starts, the same car covers fewer miles on a gallon; on a steady highway run at 60 mph it covers more. A car rated 30 mpg combined might get 26 in the city and 36 on the highway, and its window sticker shows all three.

• A Toyota Prius or similar small hybrid: 50 to 57 miles on one gallon.
• A compact sedan such as a Honda Civic or Toyota Corolla: 33 to 36 miles.
• A mid-size sedan: 30 to 33 miles for petrol, 45 to 52 for a hybrid version.
• A compact crossover such as a RAV4 or CR-V: 28 to 31 miles, or 37 to 40 for a hybrid.
• A three-row SUV: 21 to 26 miles.
• A full-size pickup: 18 to 23 miles, 25 with a hybrid powertrain.
• A large body-on-frame SUV: 15 to 18 miles.

These are approximate EPA combined figures for recent model years and the common car fuel economy table lists specific models. A twenty-year-old version of any of them would get fewer miles per gallon, and any of them driven hard in winter would too.

Divide the price of a gallon by the car's mpg to get the cost per mile. At 3.50 a gallon, a 30 mpg car costs 11.7 cents a mile to fuel, a 20 mpg pickup 17.5 cents and a 50 mpg hybrid 7 cents. Over 12,000 miles a year, that is 1,400, 2,100 and 840 respectively. The gap between the pickup and the hybrid is more than 1,200 a year at that price.

The fuel cost calculator does this for a trip or a year in any mix of units. The same sum works in any currency and any unit. A British driver paying 1.45 a litre for a car doing 45 mpg (imperial) pays 1.45 times 4.54609 for a gallon, which is 6.59, and 6.59 divided by 45 is 14.6 pence a mile.

Fill the tank, note the mileage, drive until the tank is at least half empty, fill it again and note the gallons on the receipt and the new mileage. Miles driven divided by gallons added is your miles per gallon. If the pump gave litres, convert them first with the litres to gallons page: divide by 3.785411784 for US gallons or 4.54609 for imperial ones.

The MPG calculator does the sum for you from miles and fuel in any unit, and the manual calculation guide explains how to make the result reliable: stop at the pump's first click every time, use a long sample, and average three or four tanks.

No, and it changes the answer by a fifth. The US gallon is 3.785411784 litres. The imperial gallon used for British mpg figures is 4.54609 litres, which is 20.095% more fuel, so a car goes 20.095% further on it. A car that gets 30 miles on a US gallon gets 36 miles on an imperial one.

So a British figure of 45 mpg and an American figure of 37.5 mpg describe the same efficiency. Anyone comparing a figure from one country with a figure from the other needs the US to UK mpg converter, and the gallon guide explains how the two sizes came about.

A car that gets 30 miles to the US gallon travels 48.3 km on 3.785 litres, which is 12.75 km per litre, or 7.84 litres per 100 km. Those are the two ways the rest of the world states the same fact: km/L in Japan, India and Brazil, and L/100km in Europe, Canada and Australia.

A litre of gas, for readers who buy it that way, takes a 30 mpg (US) car about 12.75 km or 7.9 miles. A 50 mpg hybrid gets 21.3 km, about 13.2 miles, from a litre.

Multiply the gallons by the car's mpg. Four gallons in a 30 mpg car is 120 miles; in an 18 mpg pickup it is 72 miles; in a 52 mpg hybrid it is 208 miles. A quarter of a 16 gallon tank is four gallons, which is why the low fuel light in a mid-size car usually comes on with about 60 to 100 miles of range left.

For the reverse, how many gallons a trip will take, divide the miles by the mpg. A 300 mile trip in a 25 mpg car needs 12 gallons, which at 3.50 a gallon is 42.

Speed above 55 mph, hard acceleration, short trips from cold, winter temperatures, a roof rack, extra weight and under-inflated tyres, roughly in that order. Together they can cut the miles you get from a gallon by a quarter compared with the sticker figure. The improving fuel economy guide puts a number on each, and the real-world MPG guide explains why the sticker is optimistic in the first place.