Calories Burned Calculator

A 160 lb (about 73 kg) person running a 10-minute mile (MET 9.8) for 30 minutes burns roughly 375 calories. The math: 9.8 × 3.5 × 73 ÷ 200 × 30 ≈ 375 kcal. Swap in your own activity, weight and time above to see your number, plus how it compares to walking, cycling, swimming and lifting for the same workout length.

The formula

Calories burned are estimated using the widely used MET equation:

The constants come from oxygen consumption: 1 MET equals about 3.5 milliliters of oxygen per kilogram of body weight per minute, and burning one liter of oxygen releases roughly 5 calories. Dividing by 200 converts those units into calories per minute, which is then multiplied by your workout duration. Heavier body weight and higher-MET activities both push the number up.

What is a MET?

A MET (Metabolic Equivalent of Task) rates how hard an activity is compared with sitting still, which is defined as 1 MET. Light activity such as slow walking is about 2-3 METs, moderate activity such as brisk walking or easy cycling is 4-6 METs, and vigorous activity such as running or fast cycling is 8 METs or more. The U.S. Department of Health and Human Services recommends at least 150 minutes of moderate or 75 minutes of vigorous activity per week for adults.

Why your weight matters most

Body weight is one of the largest drivers of calories burned, because moving more mass costs more energy. At the same MET and duration, a 200 lb person burns about 25% more than a 160 lb person and roughly 50% more than a 130 lb person. That is why two people doing the exact same class can burn very different amounts - and why the calculator asks for your weight rather than using a one-size-fits-all average.

Gross vs net calories

The MET formula returns gross calories, which include the energy your body would have used at rest during that time. To estimate net calories burned by the exercise itself, subtract about 1 MET worth (your resting rate) from the activity's MET before calculating. For everyday tracking, most apps and labels use the gross figure, so this calculator does too.

Using it for weight management

Roughly 3,500 calories is often cited as about one pound of body fat. Pairing the calories you burn here with a sensible eating plan helps you build a daily deficit, though research shows diet typically moves the needle more than exercise alone. For a full picture, combine this with your maintenance calories and a realistic target.

How to use this calculator

You only need three pieces of information to get a useful estimate. Work through the inputs in order:

1. Pick your activity: choose the option that best matches what you did. If an activity has light, moderate, and vigorous versions, select the intensity that reflects how hard you actually worked, not your best-case effort.
2. Enter your body weight: use your current weight in pounds or kilograms. This is one of the biggest factors, so an accurate number matters more than people expect.
3. Set the duration: type the minutes you spent actively doing the activity - exclude long rest breaks, water stops, or warm-up time that was much easier than the main effort.

The result updates instantly, showing total calories along with the per-minute and per-hour rate so you can compare activities at a glance. Re-run it with a different activity to see how walking, running, cycling, swimming, and strength training stack up for the same amount of time.

A second worked example: a 30-minute walk

Suppose a 180 lb (about 82 kg) person walks briskly at a 3.5 mph pace (MET 4.3) for 30 minutes. The math: 4.3 × 3.5 × 82 ÷ 200 × 30 ≈ 185 calories. Now compare the same person and the same 30 minutes on a few other activities so you can see how much intensity changes the number:

• Brisk walking (MET 4.3): about 185 calories.
• Leisurely cycling (MET 5.8): about 250 calories.
• Running a 10-minute mile (MET 9.8): about 422 calories.
• Vigorous swimming (MET 9.8): about 422 calories.

The activity you choose can more than double the result for the exact same person and time - which is why the dropdown matters as much as your weight and minutes.

Who this calculator is for

Anyone who wants a quick, research-based estimate of energy expended during exercise can use it, but a few groups get the most out of it:

• People tracking a calorie deficit who want to add a workout figure to their daily food log.
• Walkers and runners comparing routes or paces to see which session does more.
• Gym-goers deciding whether cardio or a strength session fits their time budget.
• Anyone with a fitness tracker who wants a second, formula-based number to sanity-check a watch or machine readout.
• Beginners building a routine who want to understand what "moderate" and "vigorous" actually mean in calories.

Factors that change your real burn

MET values are averages, so your true expenditure can run higher or lower than the estimate. The main variables are:

• Fitness level: a well-trained person moves more efficiently and may burn slightly fewer calories at the same pace than an untrained person.
• Terrain and incline: hills, sand, and stairs raise the MET well above flat-ground values.
• Intensity within an activity: "cycling" can be anywhere from 4 to 10+ METs depending on speed and effort.
• Body composition: more muscle mass tends to raise energy use, while the formula only sees total weight.
• Environment: heat, cold, wind, and altitude all nudge calorie burn up or down.

Tips to burn more in the same time

If your goal is to get more out of each session, a few changes have an outsized effect on the number:

• Raise the intensity: adding short bursts (intervals) pushes the average MET up without adding minutes.
• Add incline or resistance: walking uphill or increasing bike resistance can lift the MET by several points.
• Use more muscle: full-body activities like swimming, rowing, or circuit training burn more than isolated movements.
• Stay consistent: a moderate session you actually repeat beats an intense one you skip - weekly totals drive results.

Activity intensity reference

Choosing the right intensity is the single most common place people go wrong, so it helps to know roughly where each activity falls. As a quick guide for common workouts:

• Light (2-3 METs): slow walking, gentle stretching, light housework, and casual standing tasks. Good for active recovery but a modest calorie burn.
• Moderate (4-6 METs): brisk walking, leisurely cycling, doubles tennis, water aerobics, and general yard work. You can talk but not sing - this is the zone most weekly-activity guidelines target.
• Vigorous (7+ METs): running, fast cycling, lap swimming, singles tennis, and high-intensity classes. You can only say a few words at a time, and the calorie rate climbs sharply.

A simple talk test confirms the category: if you can hold a full conversation, you are likely in the light-to-moderate range; if you are too breathless to speak in sentences, you are in the vigorous range. Matching the calculator's intensity option to that real-world feel keeps your estimate honest.

Strength training and "afterburn"

The MET formula captures the calories you burn during an activity, which works well for steady cardio. Strength training and high-intensity intervals add a second effect: your metabolism stays slightly elevated for hours afterward as your body recovers, sometimes called excess post-exercise oxygen consumption (EPOC) or the "afterburn." This extra burn is real but usually modest - typically a small percentage of the workout's calories, not a workout's worth on its own. The calculator does not model afterburn, so for resistance sessions treat the number as a conservative floor rather than the full picture.

How this compares to a fitness tracker

Wrist trackers and cardio machines estimate calories from heart rate, step counts, or built-in tables, and they often read 15-30% high. The MET method here is transparent and reproducible: it uses a published value for the activity, your weight, and your time, with no proprietary algorithm. Neither approach is exact for one individual, so the smart move is to pick one method and use it consistently. This calculator is ideal as a steady baseline you can compare workouts against week to week, even if your watch shows a different headline number.

Limitations and assumptions

Treat the result as a well-grounded estimate rather than a precise measurement, and keep these assumptions in mind:

• It uses population-average MET values from healthy adults; very fit, deconditioned, older, or larger individuals can deviate.
• It reports gross calories, which include the energy you would have burned at rest during that time.
• It assumes a steady effort at the chosen intensity for the whole duration, not a mix of hard and easy stretches.
• It does not use heart-rate data, terrain, weather, or body composition, all of which affect real burn.
• It is an estimate for general fitness planning, not medical advice - consult a healthcare professional before starting a new program.

Sources

• U.S. Department of Health and Human Services - Physical Activity Guidelines for Americans.
• National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), NIH - Weight management and physical activity.
• Centers for Disease Control and Prevention (CDC) - Physical Activity Basics: measuring intensity and METs.
• National Heart, Lung, and Blood Institute (NHLBI), NIH - Energy balance, calories, and weight.