AJ Designer

Calories Burned Calculator

kg

Type minutes (e.g. 30) or use HH:MM:SS / MM:SS (e.g. 1:30:00 = 90 minutes).

Solution

—
Share:

How It Works

The Calories Burned Calculator uses the MET (Metabolic Equivalent of Task) method to estimate energy expenditure during a single bout of physical activity: kcal = MET × body weight (kg) × duration (hours). One MET is defined as the resting metabolic rate, roughly 1 kcal/kg/hour or 3.5 mL O₂/kg/min. Each activity in the dropdown has a published MET value — for example, running 6 mph is 9.8 MET, cycling moderate (12–14 mph) is 8.0 MET, and walking 3 mph is 3.5 MET. Multiply the activity's MET by body weight in kilograms and duration in hours and you get total kilocalories burned. The same formula divided by 60 gives calories per minute, and the comparison table shows what the same body weight and duration would burn across five other common activities so you can see how the choice of activity, more than the choice of effort, changes the burn.

Example Problem

A 70 kg adult runs at 6 mph (10 km/h) for 30 minutes. Running 6 mph has a MET value of 9.8 in the Compendium of Physical Activities. How many calories does the runner burn, and what is the burn rate per minute?

  1. Identify knowns: MET = 9.8 (running 6 mph), body weight = 70 kg, duration = 30 minutes = 0.5 hours.
  2. Apply the MET formula: kcal = MET × weight(kg) × duration(hr).
  3. Substitute: kcal = 9.8 × 70 × 0.5.
  4. Multiply step-by-step: 9.8 × 70 = 686; 686 × 0.5 = 343 kcal total.
  5. Compute calories per minute: kcal/min = MET × weight(kg) / 60 = 9.8 × 70 / 60 ≈ 11.4 kcal/min.
  6. Same person cycling moderate (MET 8.0) for the same 30 minutes would burn 8.0 × 70 × 0.5 = 280 kcal — about 18% less than running for the same time.

Key Concepts

The MET concept was introduced by Bruce Balke in the 1950s and standardized by the Compendium of Physical Activities (Ainsworth BE et al., Medicine & Science in Sports & Exercise, 2011 update — 43(8):1575–1581), the most widely cited reference for activity energy cost in research and clinical practice. The 2011 update lists more than 800 activity codes, each with a MET value derived from indirect calorimetry studies. By definition 1 MET ≈ 3.5 mL O₂/kg/min, which works out to about 1 kcal per kg of body weight per hour for typical adults. The values used by this calculator (3.5 MET walking, 9.8 MET running 6 mph, 8.0 MET moderate cycling, etc.) are taken directly from the Compendium. MET is a population average — measured energy expenditure varies ±15–20% across individuals at the same activity due to differences in fitness, body composition, biomechanics, terrain, and ambient conditions. For research-grade accuracy, indirect calorimetry or doubly labeled water are used; for everyday planning, MET-based estimates are accurate enough to guide calorie budgeting.

Applications

  • Estimating daily exercise calories for a weight-loss or maintenance plan — multiply by frequency per week to get weekly burn.
  • Comparing the energy cost of two workouts at the same duration (a 30-minute run vs. 30-minute strength session burns very different totals).
  • Sports nutrition planning — calculating fueling needs for long endurance bouts (hikes, cycling, running) by combining MET × duration.
  • Public-health guidance — moderate-intensity activity (3.0–5.9 MET) and vigorous (≥6.0 MET) are the official categories used by ACSM and the WHO physical activity guidelines.
  • Clinical exercise prescription — cardiac and pulmonary rehabilitation programs use MET targets to progress patients gradually from light to moderate to vigorous activity.
  • Comparing activity choices for joint health: hiking (6 MET) and elliptical (5 MET) deliver high cardiovascular work with much less impact than running.

Common Mistakes

  • Assuming the calorie number is exact. MET values are population averages — your true burn at a given activity can be 15–20% higher or lower based on fitness and efficiency.
  • Eating back every calorie a watch or app reports as 'burned'. Most consumer estimates are already MET- or heart-rate-derived with their own error bars, and stacking them on top of a TDEE that already includes activity double-counts the workout.
  • Picking the wrong MET tier — 'running' is not one number. Running 5 mph (8 MET) and running 8 mph (12.8 MET) differ by 60% per minute. Use the speed-specific entry when you know your pace.
  • Forgetting to convert pounds to kilograms. The MET formula uses kg; using lb directly inflates the answer by 2.2×. This calculator handles the conversion automatically when you toggle the unit pill.
  • Treating MET as a measure of intensity for HIIT or interval workouts. MET assumes steady-state effort. A 30-minute HIIT session with 10 minutes of work and 20 minutes of rest does not burn 8 MET × 0.5 hr — only the work intervals are at high MET. Use a heart-rate-based estimate for those.
  • Ignoring the weight dependence. A 100 kg runner burns roughly 43% more calories per minute than a 70 kg runner at the same MET. Borrowing someone else's calorie number is rarely accurate.

Frequently Asked Questions

How do you calculate calories burned by activity?

Use the MET formula: kcal = MET × body weight (kg) × duration (hours). Look up the MET value for the activity (running 6 mph = 9.8, walking 3 mph = 3.5, cycling moderate = 8.0, etc.), multiply by your weight in kilograms, then multiply by duration in hours. Example: 70 kg × 9.8 MET × 0.5 hr = 343 kcal for 30 minutes of running 6 mph.

What is the formula for calories burned during exercise?

Calories burned = MET × body weight in kg × duration in hours. MET (Metabolic Equivalent of Task) is a dimensionless number from the Compendium of Physical Activities; 1 MET ≈ 1 kcal/kg/hour ≈ 3.5 mL O₂/kg/min (resting metabolism). Calories per minute = MET × kg ÷ 60.

How accurate is the MET formula?

The MET method is a population estimate with ±15–20% individual variability. The MET value itself comes from indirect calorimetry studies on small groups, then generalized across all adults at the same activity. Real-world burn shifts with fitness level, biomechanical efficiency, terrain, ambient heat, and body composition. For a single bout, treat the answer as a starting point — accurate to within ~150 kcal for a typical 30-minute session — not an exact ledger entry.

Why does my watch say different calorie numbers?

Fitness watches typically use heart-rate-based VO₂ estimation, GPS-based pace-and-grade models, or a blend. They incorporate your resting HR, max HR, and personal fitness profile, so two different methods can disagree by 20–30% even for the same workout. The MET method is simpler — it uses only weight, duration, and activity type, so it does not adapt to fitness or heart-rate response. Neither is right; both are estimates with similar error bars.

Is MET or heart rate a better way to estimate calorie burn?

For steady-state activities (jogging, cycling at a set pace, walking, elliptical), MET-based estimates are typically within ±15% of measured values and are very stable across sessions. For interval workouts, mixed-intensity sports (basketball, soccer, tennis), or activities where pace varies a lot, heart-rate-based estimates are more responsive because they reflect the actual physiological strain. Many sports scientists combine the two — MET for the baseline, HR for the within-session adjustment.

What are the best activities for fat loss?

The best activity for fat loss is the one you can do consistently with a calorie deficit. Higher-MET activities (running, HIIT, cycling vigorous, swimming hard) burn more per minute, but lower-MET activities like brisk walking (5 MET) are easier to sustain daily and have less injury risk. For a 70 kg adult, 45 minutes of brisk walking 4× a week burns roughly 700 kcal/week — meaningful when paired with a small daily food deficit. Strength training (6 MET) burns less per minute than running but preserves muscle during weight loss, which improves long-term outcomes.

How many calories does walking burn?

Walking 3 mph (5 km/h, a casual pace) is 3.5 MET — roughly 3.5 × your body weight in kg = kcal per hour. A 70 kg adult burns about 245 kcal per hour. Walking 4 mph (6.4 km/h, brisk) is 5.0 MET, or about 350 kcal/hr for the same person. Hilly walking, walking with a loaded pack, or walking uphill on a treadmill raises the effective MET into the 6–7 range.

How do MET values compare for strength training vs. cardio?

General strength training is 6.0 MET — comparable to moderate hiking — but the effort is intermittent. A 30-minute strength session with realistic rest periods often delivers about 180 kcal for a 70 kg lifter. Running 6 mph (9.8 MET) for the same 30 minutes burns ~343 kcal. Cardio burns more per minute, but strength training preserves lean mass during weight loss, raises resting metabolic rate over time, and improves bone density and insulin sensitivity in ways pure cardio does not. Most experts recommend both.

Worked Examples

Running — Steady-State Cardio

How many calories does a 70 kg runner burn in 30 minutes at 6 mph?

A 70 kg adult runs at a steady 6 mph (10 km/h) on a treadmill for 30 minutes. Running 6 mph has a MET value of 9.8 in the Compendium of Physical Activities. What is the total energy expenditure?

  • Knowns: MET = 9.8 (running 6 mph), weight = 70 kg, duration = 30 min = 0.5 hr.
  • Apply the MET formula: kcal = MET × weight(kg) × duration(hr).
  • Substitute: kcal = 9.8 × 70 × 0.5.
  • Multiply: 9.8 × 70 = 686; 686 × 0.5 = 343.
  • Calories per minute = 9.8 × 70 / 60 ≈ 11.4 kcal/min.

≈ 343 kcal · ≈ 11.4 kcal/min

MET-based estimates assume mechanical efficiency similar to the lab subjects in the Compendium. Real-world burn can vary ±15% for hills, wind, individual fitness, and gait economy. Watches with heart-rate + GPS often estimate slightly differently because they layer in HR-based VO₂ models on top of speed.

Cycling — Long Bout

How many calories does a 70 kg cyclist burn in 1 hour at 12–14 mph?

A 70 kg rider cycles at a moderate 12–14 mph pace for 60 minutes. Cycling moderate has a MET value of 8.0. What is the total kcal cost?

  • Knowns: MET = 8.0 (cycling moderate 12–14 mph), weight = 70 kg, duration = 1 hr.
  • Apply: kcal = MET × weight(kg) × duration(hr).
  • Substitute: kcal = 8.0 × 70 × 1.0.
  • Multiply: 8.0 × 70 = 560; 560 × 1.0 = 560.
  • Calories per minute = 8.0 × 70 / 60 ≈ 9.3 kcal/min.

≈ 560 kcal · ≈ 9.3 kcal/min

Drafting in a paceline, riding on rollers, or sitting on a stationary bike with low resistance all produce different real-world MET values even at the same nominal speed. The Compendium value assumes outdoor riding on flat terrain at the stated speed.

Walking — Daily Habit

How many calories does a 180 lb adult burn walking 45 minutes at 3 mph?

A 180 lb (≈ 81.6 kg) adult walks 3 mph for 45 minutes during a lunch break. Walking 3 mph has a MET value of 3.5. What is the total burn?

  • Convert weight: 180 lb ÷ 2.20462 ≈ 81.6 kg.
  • Knowns: MET = 3.5 (walking 3 mph), weight = 81.6 kg, duration = 45 min = 0.75 hr.
  • Apply: kcal = 3.5 × 81.6 × 0.75.
  • Multiply: 3.5 × 81.6 ≈ 285.6; 285.6 × 0.75 ≈ 214.
  • Calories per minute ≈ 3.5 × 81.6 / 60 ≈ 4.76 kcal/min.

≈ 214 kcal · ≈ 4.8 kcal/min

Walking is one of the most sustainable ways to add a daily calorie deficit. Five 45-minute walks a week at this pace burn roughly 1,070 kcal — about 0.3 lb of fat per week from walking alone, without changing diet.

MET Formula for Calories Burned

The MET (Metabolic Equivalent of Task) method estimates the energy cost of physical activity as a multiple of resting metabolic rate. By definition 1 MET ≈ 1 kcal/kg/hour ≈ 3.5 mL O2/kg/min — the oxygen uptake of a healthy adult sitting quietly. Multiplying by the MET value for a chosen activity, body weight in kilograms, and duration in hours gives a first-order estimate of kilocalories burned:

kcal = MET × weightkg × durationhr
kcal/min = MET × weightkg ÷ 60

Where:

  • MET — Metabolic Equivalent of Task, a dimensionless ratio (1 MET = resting metabolism). See the activity list for the value used by this calculator.
  • weightkg — body weight in kilograms. Pounds are converted as kg = lb ÷ 2.20462.
  • durationhr — total active time in hours. Plain minutes are divided by 60; HH:MM:SS is converted to a decimal hour count.

MET values are taken from the 2011 update of the Compendium of Physical Activities (Ainsworth BE et al., Medicine & Science in Sports & Exercise, 43(8): 1575–1581). The Compendium is the most widely used reference for physical-activity energy cost in research and clinical practice. The MET method is a population estimate and carries ±15–20% variability for individual fitness, body composition, terrain, ambient temperature, and biomechanical efficiency. It is informational only and not a substitute for direct measurement (indirect calorimetry, doubly labeled water) when precise energy expenditure is needed.

Related Calculators

Related Sites