Calories Burned Calculator

How to Calculate Calories Burned

Calories burned during physical activity depend on three things: how intense the activity is, how much you weigh, and how long you do it. Exercise scientists express intensity using a MET value — Metabolic Equivalent of Task — where 1 MET is the energy your body uses just sitting quietly at rest. An activity rated at 8 MET burns roughly eight times the energy of sitting still. The MET values used in this calculator come from the Compendium of Physical Activities, a reference catalog maintained and updated by exercise-science researchers and widely used in fitness and clinical research.

$$\text{Calories Burned} = \text{MET} \times \text{weight (kg)} \times \text{time (hours)}$$

Worked Example: 30 Minutes of Moderate Cycling

A 160-pound person is about 72.6 kilograms. Moderate cycling (12-14 mph) carries a MET value of 8.0. Thirty minutes is 0.5 hours. Multiplying it out: $8.0 \times 72.6 \times 0.5 = 290.4$ calories burned — roughly 9.7 calories per minute at that pace and body weight.

Why the Same Activity Burns Different Calories for Different People

Because the formula multiplies MET by body weight, a heavier person burns more calories doing the exact same activity for the exact same duration than a lighter person does — the muscular and metabolic cost of moving a larger mass is simply higher. This is also why MET-based estimates are population averages rather than individually measured values: actual energy expenditure varies with fitness level, muscle mass, effort, terrain, and even outdoor temperature, so treat the result here as a solid estimate rather than a lab-precise number.

MET Values for Common Activities

MET values span a wide range depending on intensity — restorative activities like yoga sit around 2.5 MET, brisk walking around 3.5 MET, moderate cycling or HIIT around 8.0 MET, and all-out running can exceed 11 MET. Choosing the activity (and matching pace or effort level) that best represents what you actually did gives the most accurate estimate — a leisurely bike ride and a hard interval ride on the same bike have very different MET values.

Common Calories-Burned Estimation Mistakes

Picking a MET value for an activity's general category without matching the actual effort level — walking at a stroll versus a brisk power-walk — is one of the most common sources of an inaccurate estimate, since MET values differ significantly by pace within the same activity. Forgetting to convert weight or duration into the units the formula expects (kilograms and hours) is another frequent error when calculating this by hand instead of using a calculator that converts automatically. Treating the result as an exact number rather than a reasonable estimate can also lead to over- or under-eating relative to actual energy expenditure, especially when the number is used to "earn back" calories eaten.

Calories Burned Terms You Should Know

MET (Metabolic Equivalent of Task) — a ratio comparing an activity's energy cost to the energy cost of sitting quietly at rest (1 MET).

Compendium of Physical Activities — an academic reference cataloging MET values for hundreds of activities, maintained by exercise-science researchers and widely used as a standard source.

Energy Expenditure — the general term for calories burned through any combination of resting metabolism, digestion, and physical activity.

Active Calories — the portion of total calories burned specifically from movement and exercise, as opposed to calories burned at rest (see the Calorie Calculator for your full daily energy needs).