A Calorie Burn Calculator estimates the number of calories you burn during an activity. It typically uses your weight, activity type, duration, and intensity — often combined with BMR or MET values — to produce an estimate.

Common methods include:

• BMR-based method: Uses your Basal Metabolic Rate (BMR) and applies activity multipliers (sedentary, light, moderate, vigorous).
• METs method: Uses Metabolic Equivalent of Task (MET) values for specific activities, then calculates: Calories = MET × weight(kg) × duration(hours).
• Device-based estimates: Some calculators accept heart-rate or wearable data for a more personalized estimate.

Typical inputs are:

• Weight (kg or lbs)
• Activity type (walking, running, cycling, swimming, etc.)
• Duration of the activity
• Activity intensity (light, moderate, vigorous) or speed
• Optional: age, gender, heart rate (for more accurate results)

These estimates are approximate. Accuracy varies by method and individual differences (metabolism, fitness level, body composition). MET-based and BMR+multiplier methods provide reasonable estimates, but wearable or lab tests are more accurate.

Yes. Age, muscle mass, fitness level, and genetics all influence metabolic rate and how many calories you burn. Two people performing the same activity may burn different amounts of calories.

Combine estimated calories burned with your daily calorie intake to determine net calories. Sustained calorie deficit (burning more than you consume) leads to weight loss. Consult a nutritionist for personalized plans.

Yes — enter each activity separately and add the results to get a total calories-burned figure for the day. This helps track overall energy expenditure across workouts and daily movement.

Wearables can provide useful, personalized estimates (especially when using heart-rate data), but they also have errors. Use both tools together and consider trends over time rather than single-session values.

Variations in intensity, weather, fatigue, hydration, and recent food intake can change how many calories you burn during the same activity on different days.