Calories burned calculator

How calories burned is calculated

Every activity in the picker has a MET value: a metabolic equivalent of task. One MET is the energy you burn sitting quietly, roughly 1 kcal per kilogram of body weight per hour. An activity with a MET of 8 burns eight times that, regardless of who is doing it. The number scales with your weight because moving a heavier body costs more energy, and it scales with time because the longer you move, the more you burn.

The calculator turns a MET value into calories with the standard metabolic equation used in exercise science: calories burned equals MET multiplied by 3.5, multiplied by your weight in kilograms, divided by 200, multiplied by the number of minutes. The 3.5 and the 200 come from converting the MET definition, which is expressed in millilitres of oxygen per kilogram per minute, into kilocalories.

Worked example

Take someone weighing 70 kg cycling at a moderate effort, MET 8.0, for 30 minutes. That is 8.0 times 3.5 times 70, divided by 200, times 30, which comes to 294 kcal. Double the weight to 140 kg at the same pace and time and the answer doubles too, because the formula is linear in body weight.

The calculator does that arithmetic for whichever activity, weight and duration you enter, in metric or imperial, and shows the working underneath the result.

Why MET values, and how they compare to a fitness watch

MET values come from the Compendium of Physical Activities, a reference list built and maintained by exercise scientists that assigns a measured energy cost to hundreds of activities, from walking at a specific pace to washing a car. This calculator uses the 2011 edition. It is the same reference most exercise physiology textbooks and clinical calculators use, because the values were measured under controlled conditions rather than estimated. The compendium has been updated several times since it first appeared in 1993, each revision adding activities and refining values as more measured data became available.

MET tables

The advantage is consistency: the same activity at the same intensity gives the same answer for everyone, and the method needs only weight and time as inputs. The limit is that it assumes you are doing the activity at roughly the pace the compendium describes. Walk slower than 3.2 km/h or push harder than a listed pace and the true number drifts from the estimate.

Heart rate monitors and fitness watches

A chest strap or wrist watch measures your actual heart rate and estimates effort from that, alongside your age, sex and weight. It adapts to how hard you personally are working on the day, including hills, wind or fatigue that a flat MET value cannot see. The trade off is that consumer optical sensors are noisy, especially during fast changes in pace, and the built in formulas are rarely published. For a heart rate based estimate you can check by hand, use the calories burned by heart rate calculator, which runs the Keytel 2005 equations.

Which to trust

For a single steady activity at a known pace, a MET table and a well fitted heart rate monitor usually land within 10 to 15 percent of each other. Neither is a laboratory measurement. Use either one to guide weekly totals and trends, not to justify eating back an exact number of calories after a workout.

Calories burned at a glance

Calories burned in 30 minutes for a selection of common activities, shown for three body weights. Your own result may differ slightly depending on the exact pace or effort you select in the calculator above.

What changes how many calories you burn

Four things drive the number: how much you weigh, how hard you work, how long you keep going, and to a smaller degree how fit you already are.

Body weight

Moving more mass costs more energy at any given pace, which is why the formula multiplies MET by kilograms directly. Two people walking side by side at the same speed burn different totals if their weight differs.

Intensity

Pace, incline, resistance and effort all raise the MET value. Running at 12.9 km/h burns roughly 40 percent more than running at 8.0 km/h for the same person and the same time, because the MET climbs from 8.3 to 11.8.

Duration

The relationship with time is linear in the formula: twice the minutes, twice the calories, as long as pace stays constant. In practice pace usually drops a little over a long session, so real totals grow slightly slower than the maths implies once fatigue sets in.

Fitness level and afterburn

A trained person moves more efficiently at a given pace, which can lower the true cost slightly compared with a beginner working at the same MET. Harder efforts also trigger excess post exercise oxygen consumption, a small extra burn in the hours after you stop, which MET tables for the activity itself do not include.

How exercise compares to everyday movement

Structured exercise is not the only source of calories burned in a day. Sitting, standing, chores and casual movement all carry their own MET values, and together they can add up to more than a single workout, especially for someone with a physically active job or a habit of staying on their feet.

This is sometimes called non exercise activity thermogenesis, or NEAT: everything from standing at a desk to carrying shopping. It varies enormously between people with otherwise similar workout routines, and it is a large part of why two people who train identically can have noticeably different total daily energy expenditure.

How to use the number

The result is most useful as an input to your weekly energy balance, not as a licence to eat a specific meal afterwards.

If you are managing a deficit, add expected training burn into your activity level rather than eating it back meal by meal. The calorie deficit calculator already builds a training allowance into its activity multiplier, so treat this number as a sanity check rather than a top up.

For tracking progress over weeks, compare totals from the same activity and pace rather than switching between activities and reading too much into small differences. A 20 kcal gap between two similar sessions is noise, not a signal.

If your total daily energy expenditure feels higher than a training log alone would predict, everyday movement is usually the reason, not a measurement error. Someone who walks around a lot at work, stands for meetings or takes the stairs by default can add several hundred kcal a day compared with someone who sits for most of it, entirely outside any tracked workout.

Common mistakes

Picking a pace you are not actually holding. Choosing "vigorous" when the session was closer to moderate inflates the total by a third or more.

Stacking a watch estimate on top of a MET estimate. Use one method per session, not both added together.

Eating back the full number. Any additional food on top of a deficit already sized for your activity level cancels part of the deficit.

Ignoring body weight changes. As you lose or gain weight the calories burned for the same activity and pace change too, so an old number goes stale.

Treating a single walk or run as the whole picture. Total daily energy expenditure includes everything outside the gym, not only the tracked session.

How accurate is this, honestly

MET based estimates are built for the average adult performing the activity as described, and the typical error against directly measured oxygen consumption runs in the range of 15 to 20 percent for any one person. That is accurate enough to plan a training week and track trends, not accurate enough to be the sole input to a very tight calorie budget.

The estimate also gets less reliable at the edges: very low or very high body weights, activities done far outside the described pace, and very short sessions under five minutes where the linear formula has little data to work with. Use it as one input alongside how your weight and performance trend over weeks, not as a precise daily figure.

Combining a MET estimate with a fitness tracker

A MET based number from this calculator and a heart rate based number from a watch or chest strap are both estimates of the same underlying quantity, energy expended, arrived at through different data. When the two land close together, that agreement is a reasonable sign that both the activity you selected and the sensor reading behind the watch number are accurate for that session. When they diverge by more than roughly 20 percent, the more useful response is to check which input is more likely to be wrong for that particular session, rather than averaging the two numbers together or defaulting to whichever one happens to be higher.

Which one to default to

For a genuinely steady activity at a known, describable pace, a treadmill run held at a fixed speed, a set resistance on a stationary bike, a MET based estimate is usually the more trustworthy default, since it does not depend on how well a chest strap or optical sensor happens to be reading on that particular day. For anything less predictable, a mixed circuit class, an outdoor ride into a variable headwind, a hike with a lot of stopping and starting for photos or water breaks, a heart rate based estimate from the calories burned by heart rate calculator adapts to the real effort in a way a single fixed MET value cannot.

Mixed sessions

Many real sessions combine more than one activity, a warm up walk, a main run or ride, a cool down stretch, and applying one MET value to the whole block understates the easy parts and overstates the stretch. The more accurate approach is to estimate each distinct block separately at its own pace or effort using the picker above and add the totals together, rather than guessing at one blended average MET for the entire session and applying it across the full duration.

What still counts on a rest day

A day without a structured workout is not a day with zero movement, and treating it that way tends to make the gap between a training day and a rest day look larger than it really is. Getting dressed, walking to a car or train, standing in a kitchen and ordinary fidgeting all carry a MET value above the 1.0 baseline for sitting quietly, and together across a full day they add up to a meaningful share of total energy expenditure, often more than a single training session contributes on its own once the whole day is added up.

Non exercise activity thermogenesis on rest days

This everyday movement, sometimes summarised as NEAT, tends to fall on a genuine rest day compared with a normal working day that includes plenty of incidental walking, simply because there are fewer reasons to be up and moving without a commute or a shift on your feet. Someone recovering from a hard session by spending most of a rest day sitting is burning meaningfully less than their own average daily total, which is one reason a single rest day rarely needs the same calorie intake as a heavy training day, independent of any training specific adjustment layered on top.

Active recovery

A short, easy walk or an easy spin on a rest day sits at the light end of the MET scale in the tables on this page, low enough that it rarely interferes with recovery, while still adding a small amount to the day's total and, for many people, feeling better than complete inactivity. Treat it as a minor addition to the day's number rather than a session that needs its own dedicated calorie budget the way a structured, higher intensity workout does.

Deload and taper weeks

A planned lighter week, a deload in a strength block or a taper before a race, drops total training volume on purpose, and the calorie total from this calculator will drop along with it if you recalculate session by session. That fall in the number is expected and does not need to be matched by an equally sharp cut in food intake, since a deload week still supports recovery from the preceding weeks of harder training even though the session totals on the page look smaller than usual.

How coaches use a calories burned calculator

For a trainer building a weekly plan, the number is a starting estimate for how much a session is worth in a client's energy budget, used to set expectations rather than to chase an exact figure.

A workable approach: estimate the session burn when you programme it, fold it into the client's activity level once rather than per session, and let the scale trend and check in answers do the fine tuning from there.

Scraler logs the workouts you programme and pairs them with the nutrition targets a client is working to, so an estimated burn from a session slots into the same plan instead of living in a separate app.