How Many Big Macs in A Gallon of Gas?

April 8, 2008 – 9:27 pm

Welcome to Rough Equivalents. This is where my twisted brain comes up with odd factoids like how long it would take to drive to the moon in rush hour traffic, creating strange correlations and using odd measurements. It's fun with math, but plain enough that you don't have to be a poindexter to get it.

For the first ever exercise in Rough Equivalents I've picked Energy as the topic, most notably the amount of energy in one American gallon of gasoline/petrol (128 fluid ounces). With the price of gas rising and rising, and slated to rise some more, I thought I'd look at how much energy is in a gallon of gasoline and what that's roughly equivalent to in humanity's oldest energy source... food.

The energy available in an average gallon of gasoline, measured in joules, is around 121 megajoules, or 121 million. Lucky for us, the energy available in a food calorie can also be measured in joules as 4,187 joules. Divide 121 million by 4,187 and your rough equivalent for a gallon of gas is 28,900 food calories.

We can then start figuring out how much of various things you'd need to eat to match the energy in a gallon of gas.

• 1 gallon of gas roughly equals 53.52 Big Macs (based on 540 calories per sandwich as listed on the McDonalds web site)

• 1 gallon of gas roughly equals 22.58 gallons of nonfat milk (based on 80 calories per 8 fluid ounces)
• 1 gallon of gas roughly equals 19.35 gallons of Coca Cola classic (based on 240 calories per 12 fluid ounce serving)
• 1 gallon of gas roughly equals 13 pounds of chocolate (based on 270 calories for a 55g Hershey's milk chocolate bar)
• 1 gallon of gas roughly equals 8.93 pounds of butter (based on 1628 calories per 227g)
• 1 gallon of gas roughly equals 20.96 pounds of prime rib (based on 1038 calories per 12 ounce serving)
• 1 gallon of gas roughly equals 65.95 pounds of Oscar Mayer deli sliced smoked turkey breast (based on 60 calories per 62 gram serving)

But we can also convert a gallon of gas to exercise based on average calorie expenditures. For example, the average figure cited for a mile of leisurely walking is 100 calories. If you burned 100 calories per mile walked, you would get 289 miles per gallon.

And those are some rough equivalents. What other rough equivalents can you come up with for a gallon of gas?