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Calculate how many calories you burn during exercise. Select your activity, enter your weight and duration for instant results.
MET (Metabolic Equivalent of Task) is a standardized measure of exercise intensity. 1 MET represents the energy cost of sitting quietly (approximately 3.5 ml of oxygen per kg of body weight per minute). Activities are rated by their MET values — walking is about 3.5 METs, while running is about 9.8 METs.
Calories burned are calculated using the formula: Calories = MET × weight (kg) × duration (hours). For example, a 70 kg person jogging (7 MET) for 30 minutes burns approximately 7 × 70 × 0.5 = 245 calories. This formula provides a reliable estimate for most activities.
The WHO recommends adults get at least 150 minutes of moderate-intensity aerobic activity or 75 minutes of vigorous-intensity aerobic activity per week. Additionally, muscle-strengthening activities should be done 2 or more days per week. These guidelines support cardiovascular health, weight management, and mental wellbeing.
Several factors influence calorie burn beyond MET values: body weight and composition, fitness level, exercise intensity and technique, environmental conditions (temperature, altitude), age, and genetics. Fitter individuals may burn fewer calories for the same activity as their bodies become more efficient.
Understanding how your body produces energy during exercise helps explain why different activities burn different amounts of calories. Your body uses three energy systems, each dominant at different exercise intensities and durations. The phosphocreatine (PCr) system provides immediate energy for explosive efforts lasting 0-10 seconds, such as a single sprint or heavy lift, by rapidly regenerating ATP from stored creatine phosphate in muscles. The anaerobic glycolysis system dominates during high-intensity efforts lasting 10 seconds to 2 minutes, breaking down glucose without oxygen to produce ATP and lactate — this is the 'burning' sensation you feel during intense intervals. The aerobic system, which uses oxygen to metabolize carbohydrates, fats, and eventually protein, becomes the primary energy source for activities lasting longer than 2-3 minutes and can sustain effort indefinitely at moderate intensities. During low-intensity exercise (walking, easy cycling), your body primarily burns fat, which provides 9 calories per gram but requires more oxygen to metabolize. At higher intensities, the body shifts toward carbohydrate oxidation, which is less oxygen-efficient but provides energy faster. This is why lower-intensity exercise burns a higher percentage of fat but fewer total calories, while high-intensity exercise burns more total calories but primarily from carbohydrates. The concept of Excess Post-Exercise Oxygen Consumption (EPOC), commonly called the 'afterburn effect,' describes the elevated calorie burn that continues after exercise ends. Research shows that high-intensity interval training (HIIT) and heavy resistance training produce the greatest EPOC effect, increasing metabolic rate by 6-15% for up to 24-72 hours post-exercise, potentially burning an additional 50-200 calories.
Our calculator uses the Metabolic Equivalent of Task (MET) system, developed by Dr. Barbara Ainsworth and colleagues, and published in the Compendium of Physical Activities. The Compendium, first published in 1993 and regularly updated, assigns MET values to over 800 specific physical activities based on measured oxygen consumption. One MET equals the oxygen consumption at rest: approximately 3.5 ml of O2 per kilogram of body weight per minute, which corresponds to approximately 1 calorie per kilogram of body weight per hour. The calorie burn formula is: Calories = MET x weight (kg) x duration (hours). For example, running at 8 km/h (MET 8.3) for a 70 kg person for 45 minutes: 8.3 x 70 x 0.75 = 435.75 calories. This formula has been validated against direct calorimetry (measuring actual heat production) and indirect calorimetry (measuring oxygen consumption and CO2 production) in laboratory settings, with typical accuracy within 10-20% for most activities and individuals. However, the MET system has known limitations. MET values represent averages across populations and do not account for individual variations in movement efficiency, fitness level, or body composition. A highly trained runner may burn 10-15% fewer calories than a beginner at the same pace because their movement is more biomechanically efficient. Similarly, MET values do not capture the thermic effect of the exercise itself (muscle repair, glycogen replenishment) which occurs in the hours following the workout.
Structure your exercise program with progressive overload — gradually increasing intensity, duration, or frequency every 2-4 weeks to continue challenging your body and avoid plateaus. The most efficient approach for calorie burn combines cardiovascular exercise with resistance training. A study in the Journal of Applied Physiology found that participants who combined aerobic and resistance training lost 47% more fat than those who did only aerobic exercise. Incorporate High-Intensity Interval Training (HIIT) 2-3 times per week: alternate between 20-30 seconds of maximal effort and 60-90 seconds of recovery for 15-25 minutes. Research published in the British Journal of Sports Medicine shows that HIIT burns 25-30% more calories than continuous moderate exercise for the same duration. Use compound movements in strength training (squats, deadlifts, bench press, rows) rather than isolation exercises, as they engage multiple large muscle groups simultaneously and produce greater calorie expenditure and EPOC. Exercise in the morning if your schedule allows — research from Brigham Young University found that morning exercisers are more consistent and that morning exercise reduces food cravings throughout the day. Track your workouts to ensure you are meeting the WHO guidelines: at least 150-300 minutes of moderate-intensity or 75-150 minutes of vigorous-intensity aerobic activity per week, plus muscle-strengthening activities on 2 or more days. To prevent overtraining, follow the 10% rule — increase your weekly training volume by no more than 10% per week. Listen to your body: persistent fatigue, elevated resting heart rate, decreased performance, and mood disturbances are signs you need more recovery time.
While regular exercise provides enormous health benefits, understanding exercise-related risks helps you train safely. The most common exercise injuries are musculoskeletal: sprains, strains, and overuse injuries account for approximately 65% of all exercise-related injuries. Overuse injuries develop gradually from repetitive stress and include runner's knee (patellofemoral pain syndrome), shin splints, Achilles tendinitis, tennis elbow, and stress fractures. These are largely preventable through proper progression, adequate rest days, appropriate footwear, and cross-training to avoid repetitive strain on the same structures. Acute injuries such as ACL tears, muscle tears, and ankle sprains are more common in high-impact and team sports. Always warm up with 5-10 minutes of light activity followed by dynamic stretching before exercise, and cool down with gradual intensity reduction and static stretching afterward. Cardiac events during exercise, while rare, are a serious concern. The risk of sudden cardiac death during vigorous exercise is approximately 1 in 1.51 million exercise sessions for men and even lower for women. However, previously sedentary individuals have a temporarily elevated cardiac risk when beginning a vigorous exercise program, which is why gradual progression is essential. Exertional rhabdomyolysis, a serious condition where overworked muscles break down and release their contents into the bloodstream, can occur with extreme or unaccustomed exercise. Symptoms include severe muscle pain, weakness, and dark (cola-colored) urine and require immediate medical attention. Exercise in extreme heat without adequate hydration can cause heat exhaustion or heat stroke — exercise when temperatures exceed 35 degrees C (95 degrees F) requires careful hydration, appropriate clothing, and reduced intensity.
The Metabolic Equivalent of Task (MET) is the standardized unit used to express the energy cost of physical activities. One MET represents the rate of energy expenditure while sitting quietly at rest, which equals approximately 3.5 ml of oxygen consumed per kilogram of body weight per minute, or about 1 calorie per kilogram of body weight per hour. Activities are assigned MET values based on their measured oxygen consumption: walking at a normal pace is about 3.5 METs, meaning it requires 3.5 times more energy than resting. Running rates around 9-10 METs, swimming about 6-8 METs, and cycling 4-12 METs depending on intensity.
The calorie burn formula used in exercise science is straightforward: Calories = MET x weight (kg) x duration (hours). For example, a 70 kg person jogging (7 METs) for 45 minutes burns approximately 7 x 70 x 0.75 = 367.5 calories. This formula has been validated against direct and indirect calorimetry in laboratory settings, with typical accuracy within 10-20% for most activities and individuals. However, it does not account for the afterburn effect (Excess Post-Exercise Oxygen Consumption, or EPOC), which can add 50-200 additional calories in the hours following high-intensity or resistance exercise.
Heart rate zones provide another framework for understanding exercise intensity and are closely related to MET values. Five zones are commonly defined based on maximum heart rate (estimated as 220 minus age): Zone 1 (50-60% max HR) corresponds to very light activity, Zone 2 (60-70%) to fat-burning aerobic exercise, Zone 3 (70-80%) to moderate aerobic training, Zone 4 (80-90%) to anaerobic threshold work, and Zone 5 (90-100%) to maximum effort. Training in different zones produces different adaptations: Zone 2 builds aerobic base and fat oxidation capacity, Zone 3 improves cardiovascular fitness, and Zones 4-5 increase anaerobic capacity and VO2 max.
The Compendium of Physical Activities, first published by Dr. Barbara Ainsworth in 1993 and regularly updated, catalogs MET values for over 800 specific activities. This resource forms the scientific basis for calorie burn calculators worldwide. Importantly, MET values represent population averages and do not capture individual variations in movement efficiency. A trained runner may burn 10-15% fewer calories than a beginner at the same pace because their biomechanics are more efficient. Similarly, as fitness improves, the same activity becomes less metabolically demanding, which is why progressive overload through increased intensity, duration, or complexity is essential for continued fitness gains.
Our calculator uses the MET-based calorie burn formula: Calories = MET x weight (kg) x duration (hours). Each exercise type in our calculator is assigned a standard MET value from the Compendium of Physical Activities: Walking (3.5), Brisk Walking (4.3), Jogging (7.0), Running (9.8), Cycling (7.5), Swimming (6.0), Yoga (2.5), Pilates (3.0), Weight Training (5.0), HIIT (8.0), Dancing (4.5), Hiking (6.0), Jump Rope (11.0), Rowing (7.0), Tennis (7.3), Basketball (6.5), Soccer (7.0), and Boxing (9.0).
The formula is applied directly: for a 70 kg person running (9.8 METs) for 30 minutes, the calculation is 9.8 x 70 x 0.5 = 343 calories. The calculator also provides food equivalents (how many apples, bananas, or pizza slices the burned calories represent) and a walking-equivalent conversion, calculated by dividing the total calories burned by the per-minute calorie burn of walking at your weight. These comparisons help contextualize abstract calorie numbers into tangible daily-life terms.