Calories Burned Calculator
Calculate how many calories you burn during exercise and daily activities.
📖 What is the Calories Burned Calculator?
The calories burned calculator estimates the energy expenditure for common physical activities using MET (Metabolic Equivalent of Task) values - the established scientific standard for quantifying physical activity intensity. It tells you roughly how many calories you burn during a workout based on your body weight, the activity, and how long you do it.
MET values were developed by the American College of Sports Medicine and are compiled in the Compendium of Physical Activities, which lists hundreds of activities with standardised energy costs. A MET of 1 equals resting metabolic rate (about 1 kcal per kg per hour). Walking at 5 km/h has a MET of 3.5 - meaning it burns 3.5 times more energy than rest. Running at 10 km/h has a MET of about 8.3.
Understanding calorie expenditure from exercise helps with energy balance - the fundamental driver of body weight. If your goal is weight loss, knowing your exercise calorie burn makes it easier to plan a sustainable calorie deficit. For muscle gain or performance, it helps ensure you're eating enough to fuel training and recovery.
The fat burned estimate uses 7.7 kcal per gram of fat - accounting for the fact that fat contains 9 kcal/g but metabolising it consumes energy. This is an approximation; actual fat burn during exercise depends on intensity and your metabolic state.
📐 Formula
📖 How to Use This Calculator
💡 Example Calculations
Example 1 - 30-minute brisk walk, 70 kg person
Example 2 - 45-minute run at 10 km/h, 80 kg person
Frequently Asked Questions
🔗 Related Calculators
How are calories burned during exercise calculated?
The most common method uses MET (Metabolic Equivalent of Task) values: Calories = MET × Weight (kg) × Duration (hours). MET values are standardised effort multipliers - rest = 1 MET, brisk walking = 3.5 MET, running = 8–12 MET. This gives a reasonable estimate but individual variation (fitness level, efficiency) affects actual burn.
Does body weight affect calories burned?
Yes, significantly. A heavier person burns more calories doing the same activity because more energy is required to move greater mass. A 100 kg person running at the same pace as a 60 kg person burns roughly 67% more calories per minute.
Do I burn fat during exercise?
Your body always burns a mixture of fat and carbohydrates (glycogen). At lower intensities (Zone 2, ~65% max HR), fat provides 50–60% of fuel. At high intensities, carbohydrates dominate. However, total fat loss depends on your overall caloric balance over days and weeks, not what you burn during a single session.
Are smartwatch calorie estimates accurate?
Consumer wearables (Apple Watch, Garmin, Fitbit) have MET-based accuracy of roughly ±15–20% in studies. They are useful for tracking relative changes in activity over time, but should not be used as precise measurements for planning calorie deficits.
What activities burn the most calories per hour?
High-calorie activities per hour for a 70 kg person: Jumping rope = ~700–800 kcal, Running at 10 km/h = ~590 kcal, Cycling at 25+ km/h = ~740 kcal, Swimming laps = ~500–600 kcal, HIIT = ~600–700 kcal. Brisk walking = ~280 kcal. Intensity and body weight are the key variables.
How many calories does 30 minutes of walking burn?
Walking at a moderate pace (5 km/h) burns approximately 3.5 METs. For a 70 kg person: 3.5 x 70 x 0.5 hours = 122 calories in 30 minutes. For a 90 kg person, the same walk burns approximately 158 calories. Running at 8 km/h (8 METs) for 30 minutes burns approximately 280 calories for a 70 kg person.
Why do calorie burn estimates differ between devices and calculators?
Calorie burn estimates are based on MET (Metabolic Equivalent of Task) values, which are averages derived from group studies. Individual variation in fitness level, body composition, age, and biomechanics means actual calorie burn can differ by 15-30% from estimates. Heart rate monitors use heart rate data to personalise estimates, making them somewhat more accurate than MET-only calculations. All estimates remain approximate and are best used for tracking trends.
Why does body weight affect calories burned during exercise?
Heavier individuals do more work against gravity in most activities (walking, running, climbing) and generate more heat, burning more calories per unit time. Calories burned = MET x weight(kg) x time(hours). A 90 kg person running at 10 km/h burns ~900 kcal/hour vs 600 kcal for a 60 kg person - 50% more calories for 50% more body weight.