TDEE Calculator

What TDEE actually is

So you entered your age, sex, height, weight and roughly how often you exercise, and the tool gave you a number of calories a day. That number is your TDEE, short for Total Daily Energy Expenditure, and it is the honest answer to a simple question: across an entire ordinary day, how much energy does your body actually get through?

Not at rest, which is a different and smaller number. Not during a workout, which is a different and smaller number again. Everything. Sleeping, breathing, digesting lunch, walking to the shop, sitting in traffic, the gym session, the washing up, and the fidgeting you do without noticing. Add it all up and you have your TDEE.

It matters because it is the line you eat around. Eat consistently under it and you lose weight. Eat consistently over it and you gain. Eat near it and you stay put. Almost every calorie target you have ever been given is really a TDEE with something added or taken away.

The four things your body spends calories on

Your daily burn is not one thing. It is four, and knowing the split explains a lot about why the number behaves the way it does.

• Your resting burn is the big one, usually somewhere around 60 to 70 percent of the total. This is the energy to keep you alive doing nothing at all, and it is what our BMR Calculator works out on its own.
• Digesting your food takes roughly another 10 percent. Eating costs energy, which sounds like a loophole and is not one. Our Thermic Effect of Food Calculator covers this in detail.
• Deliberate exercise is the part everyone thinks about, and for most people it is the smallest slice of the four. An hour at the gym, three times a week, is three hours out of a hundred and sixty-eight.
• Everything else you do while awake is the fourth part, and it is the one nobody counts. Walking, standing, carrying, cleaning, pacing while on the phone, tapping your foot. It has a name, and it is the most interesting number on this page. There is a section on it below.

The activity dropdown in this calculator is really a rough attempt to bundle the last two together into one multiplier. Hold that thought.

The formula this calculator uses

The tool gets to your TDEE in two steps. First it works out your resting burn using the Mifflin-St Jeor equation, which is the most accurate of the common formulas for the general population:

Men: BMR = (10 × weight in kg) + (6.25 × height in cm) − (5 × age) + 5
Women: BMR = (10 × weight in kg) + (6.25 × height in cm) − (5 × age) − 161

Then it multiplies that resting figure by an activity factor based on what you picked:

Enter your height in centimetres or inches and your weight in kilograms or pounds; the tool converts before it calculates. And that is the whole machine. A well-validated equation, multiplied by a number from a dropdown. The first half is science. The second half, as you are about to see, is closer to an educated guess.

A worked example

Take a 30 year old man, 180 cm tall, 75 kg, who exercises moderately 3 to 5 times a week. First the resting burn:

BMR = (10 × 75) + (6.25 × 180) − (5 × 30) + 5
BMR = 750 + 1125 − 150 + 5
BMR = 1730 Calories/day

Then the activity factor for moderate exercise, which is 1.55:

TDEE = 1730 × 1.55 ≈ 2682 Calories/day

So his body gets through roughly 2,682 calories on a normal day. Eat around that and his weight holds steady.

Why the tool shows you every activity level

Notice that the calculator does not just hand you one number. It prints the whole ladder, from your bare resting rate up to the most active setting, with your choice highlighted. That is deliberate, and it is worth looking at properly.

For the man in the example above, the full table reads:

Look at the spread. Same man, same body, same equation, and yet the answer swings by more than 1,200 calories depending purely on which line of a dropdown he clicked. That is the size of a substantial meal, decided by a self-assessment nobody checks.

This is why the table is shown rather than hidden. Your true daily burn is somewhere in that column, and the honest thing a calculator can do is show you the range rather than pretend one row is the truth. Most people, when they are being straight with themselves, sit lower than they first pick. If you are torn between two rows, take the lower one and let real life correct you.

The gap the dropdown cannot see

Here is the part that changes how you should read your result. The activity dropdown asks about exercise, because exercise is easy to count. But exercise is not where most people's activity calories come from.

The energy you spend on everything that is not sleeping, eating or deliberate exercise has a name: non-exercise activity thermogenesis, or NEAT. Walking to the bus. Standing at a counter. Carrying shopping. Cooking. Pacing. Fidgeting. It sounds trivial. It is not.

Researchers at the Mayo Clinic found that NEAT varies between people of the same weight by up to 2,000 calories a day. Read that again, because it is remarkable: two people of identical size can differ by two thousand calories of daily burn purely through how much they move without calling it exercise. In an overfeeding study by the same group, the people who resisted gaining fat were the ones who unconsciously ramped up their fidgeting and moving, and those NEAT changes accounted for roughly two-thirds of the increase in their daily burn.

Now look back at the dropdown. It asks how many times a week you go to the gym. It cannot see whether you are a builder or a bookkeeper, whether you walk to work or drive, whether you sit perfectly still for nine hours or never stop moving. The single biggest source of variation in the answer is the one input the tool never asks for.

Which is not a reason to ignore your TDEE. It is a reason to hold it loosely, and to know that if you want to move your daily burn, the boring stuff between workouts has more leverage than most people credit.

Where the estimate can be off

Beyond the activity question, the usual honest limits apply:

• The equation cannot see your body composition. Same age, height, weight and sex gives the same resting figure whether you are mostly muscle or not, even though muscle burns more at rest.
• Health shifts it. Thyroid conditions, medications, pregnancy, breastfeeding and illness all move real energy needs beyond what a formula predicts.
• It is a starting point, not a prescription. The most reliable way to find your true maintenance is to eat at a steady number for a few weeks and watch what the scale actually does. The formula gives you where to start; your own results give you the answer.

If you are making real decisions about your diet, especially with a health condition in the picture, use this as background and talk it through with a doctor or a registered dietitian.

Questions people ask

What is the difference between TDEE and BMR?

BMR is what you burn at complete rest, doing nothing. TDEE is that plus everything else you do in a day. TDEE is always the larger number, and it is the one to eat around.

Which activity level should I honestly pick?

Lower than you want to. The levels refer to deliberate exercise, and most people place themselves a rung or two above where they really sit. If you are between two, take the lower one. You can always adjust upward if the scale does not move.

Should I eat my TDEE?

Eat at it to hold your weight. To lose or gain, you adjust from it, which is what our Calorie Intake Calculator and Calorie Deficit Calculator are for.

Why does another calculator give me a different TDEE?

Usually because it uses a different resting equation, or a different set of activity multipliers. Our Maintenance Calorie Calculator, for instance, uses a slightly different multiplier set and will not always agree with this one. All of them are estimates of the same thing by slightly different routes.

How often should I recalculate?

After a meaningful change in weight or in how much you move, so every few months for most people. Your TDEE drifts down as you lose weight, simply because there is less of you to run.

References

Where the figures come from. The resting equation this tool runs is Mifflin-St Jeor, published in the American Journal of Clinical Nutrition, and the point that it is the most accurate of the common equations comes from a systematic review by the Academy of Nutrition and Dietetics. The NEAT findings, including the 2,000 calorie spread between people and the overfeeding results, come from Levine and colleagues at the Mayo Clinic.

1. Mifflin MD, St Jeor ST, Hill LA, Scott BJ, Daugherty SA, Koh YO. A new predictive equation for resting energy expenditure in healthy individuals. American Journal of Clinical Nutrition. 1990;51(2):241-247. https://doi.org/10.1093/ajcn/51.2.241
2. Frankenfield D, Roth-Yousey L, Compher C. Comparison of predictive equations for resting metabolic rate in healthy nonobese and obese adults: a systematic review. Journal of the American Dietetic Association. 2005;105(5):775-789. https://doi.org/10.1016/j.jada.2005.02.005
3. Levine JA, Vander Weg MW, Hill JO, Klesges RC. Non-exercise activity thermogenesis: the crouching tiger hidden dragon of societal weight gain. Arteriosclerosis, Thrombosis, and Vascular Biology. 2006;26(4):729-736. https://www.ahajournals.org/doi/10.1161/01.atv.0000205848.83210.73
4. Levine JA, Schleusner SJ, Jensen MD. Energy expenditure of nonexercise activity. American Journal of Clinical Nutrition. 2000;72(6):1451-1454. https://pubmed.ncbi.nlm.nih.gov/11101470/