Three miles of walking burns roughly 210 to 360 calories, while three miles of running burns roughly 270 to 450 calories, depending primarily on your body weight. A person weighing around 155 pounds will land near the middle of both ranges. The reason for the wide spread is simple: heavier bodies require more energy to move the same distance.
Calories Burned Walking 3 Miles
Walking at a moderate pace (about 3 mph) carries a MET value of 3.5, which means it burns 3.5 times more energy than sitting still. For a 140-pound person, that works out to roughly 75 calories per mile, or about 225 calories over three miles. A 180-pound person covers the same distance and burns closer to 290 calories. At 200 pounds, expect around 320 calories for the full three miles.
The time commitment matters here. Three miles at a moderate walking pace takes about 45 minutes. At an easy, leisurely pace, you’re looking at a full hour. A brisk walk can get it done in around 33 minutes. The total calorie burn stays roughly the same regardless of speed because you’re covering the same distance. Walking faster just compresses the burn into a shorter window, with a slightly higher per-minute rate but a similar per-mile cost.
Calories Burned Running 3 Miles
Running the same three miles burns more total calories than walking it. At 6 mph (a 10-minute mile), running carries a MET value of 9.8, nearly three times the intensity of a moderate walk. A 140-pound runner at that pace burns about 318 calories in 30 minutes, which aligns closely with three miles. A 180-pound runner at the same pace burns roughly 408 calories over the same distance.
You may have heard the rule of thumb that running burns about 100 calories per mile. That holds reasonably well for someone in the 150- to 160-pound range. If you weigh significantly less or more than that, adjust your expectations accordingly. A 130-pound runner will burn closer to 80 calories per mile, while a 200-pound runner can exceed 120.
Why Running Burns More Than Walking
Running and walking cover the same ground, so it might seem like they should burn the same energy. They don’t, because the mechanics are fundamentally different. When you run, your body leaves the ground with each stride and absorbs impact on landing. That repeated launch-and-catch cycle demands significantly more muscle activation than the smoother, always-grounded motion of walking.
A study published in The Journal of Strength and Conditioning Research measured this directly over one mile. Walkers burned about 89 calories during the mile itself, while runners burned about 113 calories. But the gap widened further after exercise. Runners continued burning elevated calories for about 15 minutes post-workout, while walkers returned to resting levels after just 10 minutes. When that post-exercise burn was included, the total jumped to roughly 111 calories for walking and 159 calories for running per mile. Over three miles, that afterburn adds up to a meaningful difference, potentially 30 to 50 extra calories on top of what your fitness tracker shows.
How Your Weight Changes the Math
Body weight is the single biggest variable in calorie burn for any distance-based exercise. The relationship is nearly linear: a person who weighs twice as much burns close to twice the calories covering the same route at the same pace. Here’s a rough breakdown for three miles of walking at a moderate pace and running at a 10-minute mile:
- 130 pounds: ~200 calories walking, ~250 calories running
- 155 pounds: ~240 calories walking, ~300 calories running
- 180 pounds: ~290 calories walking, ~400 calories running
- 210 pounds: ~340 calories walking, ~460 calories running
These are estimates based on standard metabolic equations. Your actual burn will vary with fitness level, muscle mass, and walking or running efficiency. Trained runners, for instance, tend to burn slightly fewer calories per mile than beginners because their bodies have adapted to move more economically.
How Hills and Terrain Affect Your Burn
Adding incline dramatically increases the energy cost of covering three miles. Each 1% increase in grade boosts calorie burn by about 12% compared to flat ground. That means walking three miles on a 5% incline (a noticeable but manageable hill) burns roughly 60% more calories than the same distance on a flat surface. For a 155-pound walker, that could push a 240-calorie flat walk closer to 385 calories.
The surface you’re on matters less than you might think. Treadmill versus outdoor running produces nearly identical calorie expenditure. The small difference comes from air resistance outdoors, but it only amounts to about 1% for people running a seven-minute mile or faster. For most walkers and casual runners, there’s no practical difference. If you want to make a treadmill session match outdoor conditions exactly, setting it to a 1% incline compensates for the lack of wind resistance. Trail running on uneven ground or sand does increase energy cost more meaningfully, since your muscles work harder to stabilize with each step.
Getting an Accurate Personal Estimate
The simplest way to estimate your own burn is to multiply your weight in pounds by 0.53 for walking or 0.75 for running, then multiply by three (for three miles). These multipliers are rough but serviceable for flat terrain at moderate effort. A 170-pound person walking three miles: 170 × 0.53 × 3 = about 270 calories. The same person running: 170 × 0.75 × 3 = about 383 calories.
Wrist-based heart rate monitors and GPS watches will give you a more personalized number because they factor in your heart rate response, which captures individual fitness differences. They’re not perfect, but they’re typically within 10 to 20% of laboratory measurements. Calorie counters on gym equipment, by contrast, tend to overestimate by 15 to 30% because they often don’t account for your actual weight or effort level. If your treadmill asks for your weight before you start, the number it gives will be more reliable than one that uses a generic default.