TDEE calculator

What TDEE is and how it is calculated

Total daily energy expenditure is every calorie you burn in a day: lying still, digesting food, walking to the kitchen, training and everything in between. It is the number your weight is stable on. Eat above it and you gain, eat below it and you lose, eat at it and nothing changes.

Nobody measures TDEE directly outside a metabolic chamber, so every practical estimate, including this one, is built from smaller, better studied pieces: resting energy plus an activity multiplier. That two step approach is simple enough to redo by hand, transparent about where the uncertainty sits, and close enough to reality to be useful for setting and adjusting a calorie target.

The calculator builds TDEE in two steps.

Step 1: resting energy (BMR)

Your basal metabolic rate is what you burn at complete rest over 24 hours, just keeping organs running. By default it is estimated with the Mifflin St Jeor equation: 10 times weight in kilograms, plus 6.25 times height in centimetres, minus 5 times age, plus 5 for a man or minus 161 for a woman. For a 30 year old woman at 65 kg and 165 cm that is 650 plus 1,031 minus 150 minus 161, which comes to about 1,370 kcal.

If you enter a body fat percentage, the calculator switches to the Katch McArdle equation instead, because it uses lean body mass rather than total weight and can be more accurate when the body fat number is reliable. Lean mass is weight times one minus body fat percentage, and BMR is 370 plus 21.6 times lean mass in kilograms. Full detail on when this is worth doing is in the BMR calculator.

Step 2: the activity multiplier

BMR is multiplied by a physical activity level, or PAL, that scales it up for how much you move. The factors range from 1.2 for a sedentary desk job to 1.9 for athletes or physically demanding work, the conventional activity multiplier chart used alongside Harris Benedict and Mifflin St Jeor. A BMR of 1,370 kcal at a moderate PAL of 1.55 gives a TDEE of about 2,124 kcal, roughly 754 kcal above resting.

Which formula this calculator uses, and why

Three equations feed into the result, each doing a different job.

Mifflin St Jeor, the default

Published in 1990 from a sample of 498 adults spanning a wide range of body weights. A 2005 systematic review by the American Dietetic Association found it the most accurate of the common predictive equations for both lean and obese adults, which is why it is the default here and in most clinical dietetics.

Katch McArdle, when you enter body fat

This equation predicts BMR from lean body mass instead of total weight, so it does not penalise someone carrying more muscle the way a weight only formula can. It is only as good as the body fat percentage you put in. A number from a DEXA scan or a consistent set of skinfold readings is worth using; a guess pulled from a bathroom scale is not, and in that case Mifflin St Jeor stays the more reliable choice. Get a number first with the body fat calculator.

Harris Benedict, shown as a comparison

The original equation dates to 1919 and was revised by Roza and Shizgal in 1984. It is not the headline number here, but the calculator shows it alongside your result because it is still the equation many older tools and some clinical charts default to, and it tends to land a little higher than Mifflin St Jeor, typically by around 5 percent, especially for heavier people. Seeing both stops a mismatch with another calculator from looking like an error.

Picking the right activity level

The activity multiplier moves the result more than any other input, so it is worth getting right. The activity level bands used here, the conventional chart used alongside Harris Benedict and Mifflin St Jeor, are:

Sedentary, 1.2. Desk job, little to no structured exercise, mostly sitting.

Light, 1.375. Desk job plus one to three training sessions a week, or a job that involves some walking.

Moderate, 1.55. Three to five sessions a week, or a job that keeps you on your feet most of the day.

High, 1.725. Six to seven sessions a week, or hard physical work.

Athlete, 1.9. Two sessions a day, competitive training blocks, or manual labour on top of serious training.

Most people who think they are moderate are closer to light. A watch that says you burned 600 kcal training does not mean you should move up a band on top of choosing that band for your training; the multiplier already covers it.

A useful check is to separate your job from your training. If your job involves sitting most of the day, start from sedentary or light and let your training sessions push you up one band, not two. If your job is on your feet all day, such as retail, hospitality or trades, you can be at moderate or higher before training is even added. Reassess the band whenever your job or training volume changes meaningfully, not just once at the start.

What each band looks like in practice

Numbers make the gap between bands concrete. Take a BMR of 1,500 kcal, roughly a smaller woman or a lighter man, and run it through all five: sedentary gives 1,800 kcal, light gives 2,063 kcal, moderate gives 2,325 kcal, high gives 2,588 kcal, and athlete gives 2,850 kcal. Each step up is worth about 260 to 265 kcal, more than a coffee with milk and sugar, or a small chicken breast. Picking the wrong band by even one level is enough to stall a cut that should be working, or to explain unexpected weight gain on a bulk that looked conservative on paper. If you are between two bands, the lower one is the safer starting guess; it is easy to add calories after two weeks of data, harder to explain why a plan is not producing the loss it promised.

NEAT and EAT are not the same thing

The activity multiplier folds two very different kinds of movement into one number, and it helps to know they are being combined. Exercise activity thermogenesis, EAT, is the energy spent in deliberate training, a run, a lifting session, a class, a widely variable amount for a solid hour depending on intensity and body size. Non-exercise activity thermogenesis, NEAT, is everything else: walking to the car, taking the stairs, fidgeting, standing instead of sitting, pacing during a phone call, the small movements that fill the other 23 hours of the day. Research on NEAT has found it can vary by up to 2,000 kcal a day between two people of similar size (Levine, 2002), which is a far bigger swing than most training sessions account for.

This matters because two people who train identically, same sessions, same intensity, same weekly volume, can still land in different activity bands and end up with meaningfully different TDEE, purely because one of them has a job or a personality that keeps them moving and the other does not. It is also why bolting extra bands onto your activity level purely because you train hard is a common overestimate: the multiplier is meant to represent your whole day, not just the one or two hours you spend training. A desk based job with a strong NEAT habit, walking meetings, a standing desk, a daily dog walk, can genuinely land at light or even moderate before training is factored in at all, while an identical desk job without those habits sits more honestly at sedentary.

Why your wearable and this calculator disagree

A fitness watch and an equation based calculator are estimating the same thing, your daily energy burn, through completely different methods, so it is normal for the two numbers to differ, sometimes by several hundred calories, without either one being simply wrong.

Wearables infer calorie burn from heart rate and accelerometer data, run through an algorithm calibrated on a reference population that may not match your age, sex, body composition or fitness level particularly well. One study comparing seven wrist worn devices against indirect calorimetry, the lab standard for measuring real gas exchange, across sitting, walking, running and cycling found median energy expenditure errors ranging from about 27 percent for the best performing device to more than 90 percent for the worst, with no device reaching a rate the researchers considered acceptable (Shcherbina et al, 2017). Resistance training was not part of that particular study, but the same limitation applies at least as much to lifting as it does to steady state cardio: heart rate rises from exertion, tension and short rest breaks in a way that does not map cleanly onto actual energy expenditure the way it does for running or cycling.

The equation on this page takes the opposite approach: no sensors, no personalisation, a fixed formula built from population averages collected from a specific sample decades ago. It will not notice if your own metabolism happens to run meaningfully above or below what someone your size, age and sex averages, because it has no way to see you specifically, only people like you on paper.

Neither method is wrong so much as differently limited, and stacking them, adding a watch's exercise calories on top of an equation based TDEE that is meant to already include activity, is the single most common way people accidentally overeat while still hitting their number. If you want one figure to actually trust, two to three weeks of consistent weight trend data beats both, because it reflects what your body did rather than what either device predicted it would do. Use this calculator to set a sensible starting point, treat your wearable as a rough daily signal at best, and let the scale settle any disagreement between them.

TDEE at a glance: cut, maintain and bulk

Once you have TDEE, cutting, maintaining and bulking are just percentages of it. The table below uses a 2,500 kcal maintenance as an example; the calculator above uses your own number.

TDEE versus BMR

BMR and TDEE get used interchangeably in conversation and they should not be. BMR is what you burn doing nothing, usually 60 to 70 percent of the total. TDEE is BMR plus digestion, daily movement and training, and it is the number that actually governs your weight. Never diet off BMR: it ignores everything you do in a day and will leave you eating far too little.

If you only want the resting figure, on its own or compared across the four common equations, use the BMR calculator. This page always applies an activity multiplier on top.

What to do with your TDEE

TDEE is a starting estimate, not a measured fact. Every equation carries some error and the activity factor is a judgement call, so treat the first two weeks as calibration.

Set a target off it

Pick a goal, apply the adjustment from the table above, and eat that for two weeks while weighing yourself daily and averaging each week. If the weekly average moves at roughly the rate you expected, keep going. If not, adjust by 100 to 150 kcal and check again. For a target built around a specific rate of loss, the calorie deficit calculator does the maths for you.

Split it into macros

A calorie target on its own does not tell you what to eat. Run your TDEE, or the adjusted target from it, through the macro calculator to get protein, carbs and fat.

Recalculate as things change

TDEE falls as you lose weight and rises as you gain muscle or add training volume. Rerun the numbers every 5 kg of change or every two months, whichever comes first.

Treat the first estimate as a hypothesis

No equation knows your actual metabolism, only a population average for someone your size, age and sex. Two people with identical stats can have a genuinely different TDEE because of muscle mass, genetics, sleep, stress and how active they really are between formal training sessions. The number from the calculator gets you into the right range fast, but the number that actually works is the one your own weight trend confirms over two to three weeks of consistent tracking.

Common mistakes

Overstating activity level. Training three times a week while sitting at a desk the rest of the time is light activity, not moderate. Pick the lower band when unsure.

Confusing BMR with TDEE. Eating at your BMR ignores every calorie you burn moving and training, and it is far too low to sustain.

Treating the number as fixed. TDEE is not permanent. It falls as you lose weight and shifts with training changes, illness and even the weather.

Trusting a wearable over the equation without checking. Fitness trackers estimate calorie burn with their own errors, often overestimating high intensity work. Use the calculator as the baseline and adjust from real weight trend data.

Entering a guessed body fat percentage. A rough guess plugged into Katch McArdle can move BMR by hundreds of calories. If you are not confident in the number, leave it out and let the calculator use Mifflin St Jeor.

How coaches use a TDEE calculator

For a coach, TDEE is the opening estimate of a nutrition plan, never the plan itself. It sets where to start; the actual work is watching the trend and adjusting.

A simple routine: calculate TDEE at onboarding using the client's reported activity, set the target and protein, then review the weekly weight average every check-in and move the target in small steps rather than resetting it from scratch each time. Clients who see the same target quietly adjusted based on their own trend tend to trust the process more than one who gets a brand new number every few weeks with no explanation.

Scraler runs that loop for you. Set a calorie target per client, have them log meals and weight in the app, and see the weekly trend and adherence in one view instead of rebuilding a spreadsheet for every client. See nutrition coaching or read how hybrid personal training folds nutrition targets into a training programme.