Walking 3 miles burns roughly 200 to 350 calories for most adults, depending primarily on body weight. A 150-pound person burns about 225 calories over that distance, while someone weighing 220 pounds burns closer to 350. Your pace, the terrain, and whether you’re walking uphill all shift that number further.
Calories Burned by Body Weight
Body weight is the single biggest factor in how many calories you burn walking any distance. Heavier bodies require more energy to move, so a larger person burns significantly more per mile than a smaller one. At a typical walking pace on flat ground, here’s what 3 miles costs in calories:
- 120 lbs: ~192 calories
- 140 lbs: ~222 calories
- 160 lbs: ~255 calories
- 180 lbs: ~288 calories
- 200 lbs: ~318 calories
- 220 lbs: ~351 calories
- 250 lbs: ~399 calories
- 300 lbs: ~480 calories
You may have heard the rule of thumb that walking burns about 100 calories per mile. That’s a reasonable shortcut for someone around 180 pounds, but it overstates the burn for lighter people and understates it for heavier ones. A study published in the Journal of Strength and Conditioning Research measured energy expenditure across body types and found that mass and sex were the strongest predictors, with women burning slightly fewer calories per mile than men of the same weight.
How Walking Speed Changes the Burn
Walking faster does burn more calories per minute, but the relationship isn’t as dramatic as you might expect. Researchers use a measurement called a MET value to compare the intensity of different activities. A slow stroll (2.0 to 2.4 mph) registers at 2.8 METs. A moderate pace (2.8 to 3.4 mph) jumps to 3.8 METs. And a very brisk walk (4.0 to 4.4 mph) hits 5.5 METs, nearly double the slow walk.
In practical terms, that means a 160-pound person walking 3 miles at a brisk 4 mph pace burns roughly 370 calories, compared to about 255 at a moderate pace. The tradeoff is time: a brisk walk finishes the 3 miles in about 45 minutes, while a moderate pace takes closer to an hour. Since you’re covering the same distance either way, the per-mile calorie difference comes from your muscles working harder to maintain the faster turnover.
How Long 3 Miles Takes
The average adult walks at about 3 miles per hour, which puts a 3-mile walk right at 60 minutes. That pace holds fairly steady from your 20s through your 50s, though it starts to slow after 60. Adults in their 70s typically average 2.5 to 2.8 mph, which stretches a 3-mile walk to about 65 to 72 minutes.
If you’re walking briskly at 3.5 mph, you’ll finish in roughly 51 minutes. At a very brisk 4 mph, you’re looking at 45 minutes. And if you’re taking a more leisurely stroll at 2.5 mph, plan for about 72 minutes.
Walking Uphill Burns Significantly More
Terrain is the easiest way to increase your calorie burn without walking farther. For every 1% increase in incline, a 150-pound person burns about 10 extra calories per mile, roughly a 12% increase. That adds up quickly. At a 5% grade (a noticeable but comfortable hill), you’re burning about 60% more per mile than on flat ground. At a 10% grade, you’re burning more than double.
For a 150-pound person, that means 3 miles on flat ground burns about 225 calories, but the same distance at a 10% incline burns closer to 475. If you walk on a treadmill, this is easy to control. Outdoors, hilly routes or staircase walks can replicate the effect without needing a precise grade.
Walking on soft surfaces like sand or grass also increases your burn compared to pavement, though the effect is smaller and harder to quantify than incline.
How Many Steps That Is
Three miles of walking works out to roughly 6,000 steps for most people, though your height and stride length shift that number. A person who’s 5’4″ takes about 2,357 steps per mile, putting 3 miles at around 7,070 steps. Someone who’s 5’10” covers a mile in about 2,155 steps, so 3 miles equals roughly 6,465 steps. And at 6’2″, the count drops to about 6,117 steps for the same distance.
If you’re tracking steps on a fitness watch or phone, these numbers give you a reasonable target. The popular 10,000-step goal translates to roughly 4.5 to 5 miles for most adults, so a 3-mile walk gets you about 60% of the way there.
Why Calorie Estimates Vary Between Apps
If your fitness tracker shows a different number than the charts above, that’s normal. The calorie figures here are based on the Compendium of Physical Activities, a standardized database used in exercise science research. Most fitness watches and apps use similar formulas but layer in additional variables like heart rate, arm swing, and estimated fitness level, which can push their estimates higher or lower.
Heart rate monitors tend to overestimate calorie burn during lower-intensity activities like walking, because your heart rate can be elevated by caffeine, stress, or heat without your muscles actually doing more work. The weight-based estimates above are a more reliable baseline. If your tracker consistently shows 20 to 30% more than these numbers, the tracker is likely being generous.