Exercise Calories Burned Calculator
Estimates the calories you burn during exercise based on your weight, activity type, duration, and intensity. Use it after a workout to track energy expenditure or plan a calorie deficit.
About this calculator
This calculator estimates calories burned using a MET-based approach. MET (Metabolic Equivalent of Task) represents how many times more energy an activity burns compared to rest. The core formula is: Calories = MET × weight_kg × (duration_min / 60) × intensity_factor. Your weight in pounds is first converted to kilograms by dividing by 2.205. The duration in minutes is divided by 60 to express it in hours. The exercise type provides the MET value, and the intensity multiplier scales the result up or down based on effort level. This method is widely used in exercise science and gives a reliable estimate for aerobic and resistance activities alike.
How to use
Suppose you weigh 180 lbs, run for 45 minutes, with a MET value of 8 for running and an intensity factor of 1.0. Step 1 — Convert weight: 180 / 2.205 = 81.6 kg. Step 2 — Convert duration: 45 / 60 = 0.75 hours. Step 3 — Apply formula: 8 × 81.6 × 0.75 × 1.0 = 489.6, rounded to 490 calories. That means a 180 lb person burns roughly 490 calories on a 45-minute moderate-intensity run.
Frequently asked questions
How accurate is a MET-based calories burned calculator for exercise?
MET-based estimates are reasonably accurate for most healthy adults and are the standard method used in published exercise research. However, individual factors like fitness level, muscle mass, and biomechanical efficiency can cause actual calorie burn to vary by 10–20% from the estimate. For the most precise measurements, a metabolic cart or heart-rate-based monitor would be needed. That said, MET calculations are reliable enough for tracking trends and planning a calorie deficit over time.
Why does body weight affect how many calories you burn during exercise?
Heavier individuals expend more energy performing the same activity because it requires more effort to move a larger mass. The MET formula scales calories linearly with body weight in kilograms, meaning a 200 lb person burns roughly 25% more calories than a 160 lb person doing the same workout. This is why weight loss itself can gradually reduce calorie expenditure, requiring adjustments to exercise duration or intensity to maintain progress.
What intensity level should I enter for moderate versus vigorous exercise?
Intensity in this calculator acts as a multiplier on the base MET value. A factor of 1.0 represents the standard MET for that exercise at a typical pace. Values above 1.0 (e.g., 1.2–1.5) reflect vigorous effort — think sprinting instead of jogging or heavy resistance training. Values below 1.0 (e.g., 0.7–0.9) suit light effort such as a casual walk. Matching the intensity factor to your perceived exertion makes the estimate considerably more accurate.