Calories Burned Calculator

The number of calories you burn during everyday activities or workouts depends on a variety of personal factors, so it’s not an exact science. This calculator provides an estimated value based on standardized data that reflects an “average” individual. Details about the formula and how it works can be found in the “How Calories Are Calculated” section below.

If you’re interested in learning how many calories you need each day to maintain, lose, or gain weight, check out our Calorie Calculator. In general, your weight changes depending on the balance between the calories you eat and the calories you burn through daily activity and your basal metabolic rate (BMR). If the balance is zero, your weight stays the same. A negative balance usually leads to weight loss, while a positive one leads to weight gain. For more details on BMR, refer to our BMR Calculator.

Key Factors That Influence Calories Burned

Several variables impact how many calories your body burns during any activity. Our calculator mainly considers three important elements: body weight, duration of the activity, and MET (Metabolic Equivalent of Task) values.

1. Body Weight and Duration

Body weight plays a significant role in calorie burn—even when you’re resting. Heavier individuals naturally burn more calories because their bodies require more energy to function. This effect becomes more pronounced during physical activity. For example, a person weighing 200 pounds will burn more calories running a mile than someone weighing 100 pounds, assuming all other factors are equal.

Exercise duration also matters. The longer you engage in an activity, the more calories you’ll burn. However, intensity also plays a role—walking 5 miles in an hour burns more calories than walking 1 mile in the same amount of time.

2. Exercise Intensity

The intensity of an activity greatly influences how many calories are burned. This can be measured in several ways:

• Heart Rate: A higher heart rate usually means the activity is more intense, though this isn’t always a perfect measure due to individual differences in fitness and heart health.

• Oxygen Consumption: A more accurate method is measuring how much oxygen you use during exercise. There’s a direct relationship between oxygen consumption and exercise intensity—the more intense the exercise, the more oxygen your body requires.

This brings us to METs. MET is a unit that helps measure the intensity of a physical activity. One MET represents the amount of energy used at rest (about 3.5 mL of oxygen per kilogram per minute). A MET of 2 indicates twice the energy use of resting, while a MET of 8 means eight times the energy output.

Here are some examples of MET values:

• 2.0 MET – Slow walking (light intensity)

• 5.0 MET – Doubles tennis (moderate intensity)

• 11.0 MET – Jumping rope at 100 jumps/min (vigorous intensity)

Fat Burning and Intensity

If your goal is to burn fat, lower-intensity exercises over a longer duration are typically more effective. As exercise intensity increases, your body begins to use more carbohydrates for energy instead of fat.

3. Additional Influencing Factors

While body weight, activity duration, and intensity are core components, other factors can affect calorie expenditure too:

• Age: Older individuals often burn fewer calories due to reduced muscle mass.

• Body Composition: Muscle burns more calories than fat, so having more muscle increases calorie burn.

• Environmental Temperature: Warmer environments can slightly increase calorie burn as the body doesn’t need to generate as much heat.

• Fitness Level: Fitter individuals tend to burn fewer calories for the same activity because their bodies are more efficient.

• Diet: Eating habits can impact metabolism, affecting how quickly calories are burned.

• Sleep: Poor sleep can slow metabolism and reduce physical activity, resulting in fewer calories burned overall.

How Calories Are Calculated

The following formula is used to estimate calories burned:

Calories Burned = (Time × MET × Body Weight in kg) ÷ 200

This equation, along with standardized MET data from scientific studies, helps estimate calorie burn based on your body weight and how long you perform an activity.

Understanding Accuracy

These calculations offer general estimates, not exact figures. The standard 1 MET value was originally based on a healthy 40-year-old man weighing 70 kg. Because every individual has unique traits like body composition, age, and fitness level, the actual number of calories burned can vary widely.

Additionally, many physical activities aren’t performed at a constant rate. For example, playing tennis may include breaks, which can lead to overestimating calorie burn if the entire session duration is counted.

For the most precise measurement, professional testing in a lab is needed—something not practical for most people. That’s why MET-based estimates are commonly used. They serve as useful tools to understand relative exercise intensity and provide a solid reference point for setting personal fitness goals.