How Many Calories Do You Lose Per Mile?

The exact number of calories you burn for every mile you run or walk depends on a number of factors, from your body weight, overall body composition and how fast you go, right down to your genetic makeup. However, you can make some helpful estimates based on body weight and speed.

Unless you're hooked up to clinical equipment, it's almost impossible to determine exactly how many calories you burn when you work out. An online calories-burned-running calculator can be very helpful, but it's still just an estimate.

That's because, as the Mayo Clinic explains, a great many factors affect the actual number of calories you burn during any given workout. They range from things you have absolutely no control over, such as your gender, hormone levels and genetic predisposition, to factors that you can affect in the moment (the intensity and duration of your workout) and factors that you can gradually affect over time (your body weight and body composition).

As if that wasn't all vague enough, clinical trials have also shown that most fitness trackers are quite inaccurate when it comes to estimating calories burned. For example, in a May 2017 issue of the Journal of Personalized Medicine, researchers recruited a small group of 60 volunteers to evaluate seven fitness-tracking devices and found that they were all wildly inaccurate when it came to estimating calories burned. Even the most accurate device was off by 27 percent, while the least accurate was off by 93 percent.

That might all sound a little discouraging, but the good news is that even if calorie-burn estimates aren't 100 percent exact, they're still useful for estimating your daily energy balance — or to put it another way, the balance between calories you take in versus calories you burn. You can also use calorie-burn estimates to track your progress over time (as you get more fit and more active, the number will go up) and to gauge the relative intensity of your workouts.

The trick is to use the same device, method or calorie calculator so that the relationship between any estimates you get stays constant. (If you poke around in different online calorie calculators, you'll see that their estimates for the same activities can vary quite a bit.)

Of course, those numbers can be great for impressing your friends or just cheering each other on, because the accountability and positive support you get from peer groups are most definitely "things" when it comes to meeting your fitness goals.

Read more: Burning Belly Fat: Run or Walk?

With all that in mind, here are some useful estimates of how many calories you can burn per mile according to your pace and your body weight, based on figures from Harvard Health Publishing and starting with a body weight of 135 pounds. As you'll see, although the specific numbers do vary somewhat, there's a general threshold for how many calories you burn at a specific body weight per mile at a run or walk.

If you weigh 135 pounds and walk or run at the following paces, you could burn:

• 3.5 mph: 69 calories/mile (walking)
• 4 mph: 68 calories/mile (walking)
• 4.5 mph: 67 calories/mile (walking)
• 5 mph: 96 calories/mile (running)
• 6 mph: 100 calories/mile (running)
• 7.5 mph: 100 calories/mile (running)

Read more: Normal Speed for Jogging

If you weigh 155 pounds and run or walk at the same paces, you could burn this many calories:

• 3.5 mph: 85 calories/mile (walking)
• 4 mph: 84 calories/mile (walking)
• 4.5 mph: 83 calories/mile (walking)
• 5 mph: 119 calories/mile (running)
• 6 mph: 124 calories/mile (running)
• 7.5 mph: 124 calories/mile (running)

And if you weigh 185 pounds and walk or run at the specified paces, you could burn this many calories:

• 3.5 mph: 102 calories/mile (walking)
• 4 mph: 100 calories/mile (walking)
• 4.5 mph: 99 calories/mile (walking)
• 5 mph: 142 calories/mile (running)
• 6 mph: 148 calories/mile (running)
• 7.5 mph: 148 calories/mile (running)

Hopefully, you like the "calories burned per mile" estimates that you're seeing. If you don't, the obvious answer is to run or walk faster — but that isn't always an option, especially when you're first starting out. In fact, working out too hard, too soon is a good way to get injured and set yourself back instead of advancing toward your fitness goals.

However, as long as you introduce any new challenges gradually, there are several ways you can up your calorie burns right away. The simplest is to run or walk just a little farther at every workout. That gradual increase gives your body time to adapt to the new levels of exertion and weight-bearing exercise. Another option is to walk or run up hills — that harder workout is a sure way to burn more calories.

And finally, even if you can't increase your overall speed or workout time, you might be able to squeeze a few short intervals — walking or running faster for a short period, then slowing back to your normal pace — into your workout. Those intervals are a great way to burn more calories in the same amount of time.

Your body also needs a certain amount of rest to rebuild and prepare for the next workouts. If you're so focused on reaching a certain number of calories burned that you never give yourself a break, you might experience some of the unpleasant — and dangerous — symptoms of overtraining. As explained by the American Council on Exercise, these include sleep disturbances, fatigue, nagging injuries, everything feeling harder than it should, and even depression or altered mood.

The simple solution? Start with whatever level of exertion your body is at — not where you wish it were — and gradually increase your workout duration, intensity or frequency from there. You might just see that you advance faster than you expect.

You should also give yourself at least one full rest day per week, and pay attention to what your body tells you between workouts. Some mild soreness or tiredness is normal after a tough workout, but it shouldn't be extreme — and any feelings of fatigue should quickly fade as your body rebuilds its energy stores. Your workouts should, on balance, be energizing instead of fatiguing.