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Calories Burned Calculator

What Is a MET and How Does It Measure Calories?

A MET (Metabolic Equivalent of Task) is a unit that measures the energy cost of physical activity relative to rest. One MET equals the energy your body uses while sitting quietly — approximately 3.5 mL of oxygen per kilogram of body weight per minute, or about 1 kilocalorie per kilogram per hour. When an activity has a MET value of 5, it means you're expending five times more energy than at rest. The MET system was developed by researchers to standardize how we compare the intensity of different activities, from light housework to competitive athletics. The 2011 Compendium of Physical Activities catalogs 821 activities with their measured MET values, making it the most comprehensive scientific resource for estimating calorie expenditure. This calculator uses the standard formula: Calories = (MET × 3.5 × weight in kg) / 200 × duration in minutes.

How to Get Accurate Results

For the most accurate calorie estimate, select the activity that most closely matches what you actually did — intensity matters significantly. A casual neighborhood bike ride (4.0 METs) burns roughly half the calories of moderate road cycling at 12-14 mph (8.0 METs). Enter your actual body weight, as it directly affects the calculation: a 200 lb person burns about 30% more calories than a 150 lb person doing the identical activity. Duration should reflect your active exercise time, excluding warm-up, cool-down, and rest periods between sets. Keep in mind that MET values represent steady-state energy expenditure — if you took breaks during your workout, your actual burn will be somewhat lower than the estimate. For weight training, count total time including rest between sets, as the MET value already accounts for typical rest intervals.

Frequently Asked Questions

What is a MET and why is it used to calculate calories?

A MET (Metabolic Equivalent of Task) measures how much energy an activity requires compared to sitting at rest. One MET equals approximately 1 kcal/kg/hour. The system was developed by exercise scientists and is used by the American College of Sports Medicine, the WHO, and researchers worldwide. It provides the most standardized and scientifically-validated way to estimate calorie expenditure across different activities.

How accurate is this calories burned calculator?

MET-based calculations are considered the gold standard for estimating energy expenditure from self-reported activity, with typical accuracy within ±15-20%. However, individual factors like fitness level, body composition, exercise technique, and environmental conditions can affect actual calorie burn. For comparison, consumer fitness trackers have been shown to overestimate by 27-93% in research studies.

Does body weight really affect how many calories I burn?

Yes, significantly. Body weight is directly proportional in the calorie formula — a 200 lb person burns roughly 33% more calories than a 150 lb person doing the exact same activity for the same duration. This is because moving a heavier body requires more energy. It's one of the most important variables in the calculation.

What exercise burns the most calories?

Based on MET values, the highest-calorie activities include running at 10 mph (14.5 METs), swimming butterfly (13.8 METs), running at 9 mph (12.8 METs), and jump rope (10.0 METs). However, sustainability matters — most people can sustain moderate activities like brisk walking or cycling much longer, potentially burning more total calories per session.

Why does this calculator show different results than my fitness tracker?

Fitness trackers use heart rate and accelerometer data with proprietary algorithms, while this calculator uses scientifically-measured MET values from the Compendium of Physical Activities. Research from Stanford University found that popular wearable devices overestimate calorie burn by 27-93%. MET-based calculations, while not perfect, use validated scientific data and are generally considered more reliable for estimating exercise energy expenditure.

Does this include the 'afterburn effect' (EPOC)?

No, MET values measure the energy cost during the activity itself. EPOC (Excess Post-Exercise Oxygen Consumption), often called the 'afterburn effect,' can increase your total calorie expenditure by 6-15% for moderate exercise and up to 15-25% for high-intensity exercise. This additional burn occurs in the hours following vigorous activity as your body returns to its resting state.

How many calories should I burn per day through exercise?

The American Heart Association recommends at least 150 minutes of moderate-intensity aerobic activity (3.0-6.0 METs) or 75 minutes of vigorous activity (>6.0 METs) per week. In MET-minutes, the target is 500-1,000 MET-minutes per week for substantial health benefits. For weight loss, creating a deficit of 500-750 calories per day through a combination of diet and exercise is commonly recommended.

Are the MET values the same for everyone?

MET values from the Compendium are population averages based on measured oxygen consumption in adults aged 19-59. Trained athletes may be more metabolically efficient (burning slightly fewer calories), while beginners or older adults may burn slightly more. The standard baseline of 3.5 mL O₂/kg/min was derived from a 70 kg, 40-year-old male, so individual resting metabolic rates may differ.