It doesn't get any better than heading outside and going for a killer run under the sun….Well, there's actually one thing that can make that run better: knowing exactly how many calories you burned while doing it. Tracking calories definitely isn't for everyone, and that's perfectly fine. But some of us only feel seriously accomplished knowing that number. 

Julie Upton, RD, tells Health that as a very general estimate, you can assume you burn about 100 calories per mile. Again, that's super general, and we know sometimes you want to nail the amount down more specifically. To get a more accurate number, you have to factor in both your weight and speed. 

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The faster you run, the more calories you burn. The same goes for weight: The more you weigh, the more you burn while exercising. If two people run the same distance at the same speed, the person who weighs more will always burn more calories. 

"The person who weighs more has to move a heavier body against gravity," says Cynthia Sass, RD, Health contributing nutrition editor. "It's harder to move a 165-pound body than it is a 150-pound body, so it burns more calories." 

As to why a faster pace burns more, Sass says, "When you're running faster, your cells are working harder, so you're burning more calories." That means if you run three miles in 30 minutes or three miles in 45 minutes, you'll always burn more calories doing it in 30. 

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So how can you know how many calories you're burning per mile? A chart by The American Council on Exercise says a 140-pound person burns about 13.2 calories per minute running. Let's say that person runs a 10-minute mile; that means they’ll burn 132 calories per mile. A 160-pound person, on the other hand, burns about 15.1 calories per minute, putting them at a 151 calories per mile.

If you want to get even more specific, you can check out MyFitnessPal's calories burned calculator. Enter your running speed (e.g. 10-minute mile), your weight, and the duration of your run—and viola, you'll have your calories burned number. This calculator also estimates the calories burned for other exercises, like spinning, hiking, and rowing. 

Before you get too caught up in counting calories, Sass says to remember that there's much more to staying healthy than tracking calories in versus calories out. "The key to exercise and weight management is consistency—consistency with a healthy, balanced diet and moving your body. It doesn't have to be the toughest workout, as long as you're getting your heart rate up, you enjoy it, and you can do it regularly." 

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