Forty minutes of walking burns roughly 150 to 250 calories for most people. The exact number depends on how fast you walk, how much you weigh, and the terrain you’re covering. A 155-pound person walking at a brisk 3.5 mph pace will burn about 210 calories in 40 minutes, while a lighter or slower walker might burn closer to 145.
Calorie Burn by Speed and Body Weight
Your body weight and walking speed are the two biggest factors in how many calories you use. Heavier bodies require more energy to move, and faster paces demand more work from your muscles with every step. Using the standard energy expenditure formula (0.0175 × MET value × body weight in kilograms × minutes), here’s what 40 minutes of walking looks like across common weights and speeds:
Moderate pace (3.0 mph, about a 20-minute mile):
- 130 lbs: ~145 calories
- 155 lbs: ~173 calories
- 185 lbs: ~206 calories
Brisk pace (3.5 mph, about a 17-minute mile):
- 130 lbs: ~178 calories
- 155 lbs: ~212 calories
- 185 lbs: ~253 calories
Very brisk pace (4.5 mph, about a 13-minute mile):
- 130 lbs: ~289 calories
- 155 lbs: ~346 calories
- 185 lbs: ~412 calories
The jump between moderate and very brisk is dramatic. Walking at 4.5 mph doubles the MET value (a measure of exercise intensity) compared to 3.0 mph, which means it burns roughly twice the calories in the same amount of time. That said, 4.5 mph is closer to a power walk or light jog for most people, and it’s difficult to sustain for a full 40 minutes without training.
How the Calculation Works
Every physical activity is assigned a MET value, which stands for Metabolic Equivalent of Task. Sitting quietly is 1.0 MET. Walking at a slow 2.0 mph pace is 2.8 METs, meaning it burns 2.8 times more energy than sitting still. A brisk 3.5 mph walk is 4.3 METs, and a very fast 4.5 mph walk is 7.0 METs.
To estimate your own calorie burn for 40 minutes of walking, use this formula: divide your weight in pounds by 2.2 to get kilograms, then multiply that by the MET value for your speed and by 0.0175, then multiply the result by 40. For example, a 170-pound person walking at 3.5 mph: 170 ÷ 2.2 = 77.3 kg × 4.3 METs × 0.0175 = 5.8 calories per minute × 40 = about 232 calories.
Walking on Hills and Uneven Ground
Flat pavement gives you the baseline numbers above, but adding incline changes the math quickly. Each 1% increase in grade adds roughly 12% more calories burned compared to walking on flat ground. So if you’re on a treadmill set to a 5% incline, or walking up a moderate hill, you could be burning 50 to 60% more than the flat-ground estimates. A 155-pound person who would normally burn 212 calories in 40 minutes of brisk walking on flat ground could burn closer to 320 calories on a steady uphill route.
The surface underfoot matters too. Walking on sand, thick grass, or uneven trails forces your muscles to work harder because the ground gives way beneath your feet. Research from the University of Liverpool found that softer, more “compliant” surfaces cause longer strides and increase the workload on hip and knee muscles. You won’t find a clean percentage for every surface, but expect a noticeable increase in effort and calorie burn on a beach or soft trail compared to a sidewalk.
Walking vs. Running for the Same Time
Running burns roughly double the calories of walking over the same time period. If a 40-minute brisk walk burns around 210 calories for a 155-pound person, a 40-minute moderate jog would burn closer to 400 to 450. The tradeoff is impact on your joints, recovery time, and sustainability. Many people can walk for 40 minutes daily without any issue, while running that frequently takes more conditioning.
There’s one interesting exception: power walking at 4.5 mph burns the same calories per hour as jogging at 4.5 mph. At that speed, walking actually becomes less mechanically efficient than running, so your body works harder to maintain the walking gait. If you can sustain that pace, you get a running-level calorie burn with lower impact.
Practical Ways to Burn More
If your goal is to increase calorie burn without walking longer, speed is the most effective lever. Going from a moderate 3.0 mph to a brisk 3.5 mph adds about 20% more calories. Pushing to 4.0 mph or above adds significantly more, though it takes some practice to walk that fast comfortably.
Adding hills or using a treadmill incline is the next best option. Even a modest 3% grade, barely noticeable visually, would add roughly 36% more calorie burn based on the 12%-per-percent-grade estimate. Combining a brisk pace with a moderate incline is one of the most efficient ways to get a higher-intensity workout from walking alone.
Carrying extra weight, whether in a backpack or a weighted vest, also increases energy expenditure because your body has to move more mass with every step. Walking on soft sand, trails with roots and rocks, or grass all demand more stabilization from your legs and core, quietly increasing your calorie burn without any change in speed or distance.