How to calculate your TDEE

What TDEE actually measures

TDEE stands for Total Daily Energy Expenditure: the total number of calories your body burns in a typical day, from breathing and pumping blood to walking, working, and training. It is the single most useful number in any weight plan, because eating below it, at it, or above it is what drives fat loss, maintenance, or gain.

TDEE is built from four parts. The largest by far is your resting metabolism, the energy you would burn lying still all day. On top of that sits the calories burned digesting food, the calories from deliberate exercise, and the calories from everyday movement like fidgeting, standing, and chores. You cannot measure all of that at home, so we estimate the resting piece with a formula and scale it up with an activity factor.

• Resting metabolism (BMR): usually 60 to 70 percent of the total
• Thermic effect of food: roughly 10 percent, from digestion
• Exercise activity: your workouts
• Non-exercise activity: walking, standing, fidgeting, daily life

Step 1: Find your BMR with Mifflin-St Jeor

Basal Metabolic Rate (BMR) is the calories you burn at complete rest. The Mifflin-St Jeor equation is the modern standard because it tracks real-world resting metabolism more closely than older formulas for most people. It uses weight in kilograms, height in centimeters, and age in years, with a different constant for men and women.

If you think in pounds and feet, convert first: divide pounds by 2.205 for kilograms, and multiply inches by 2.54 for centimeters. The whole equation is just multiplication and addition, so you can run it on any phone calculator or let the tool do it.

• Men: BMR = 10 x kg + 6.25 x cm - 5 x age + 5
• Women: BMR = 10 x kg + 6.25 x cm - 5 x age - 161
• The only difference between the two is the final number: +5 for men, -161 for women

Step 2: Multiply by your activity factor

BMR is only rest. To reach TDEE you multiply it by an activity factor that reflects how much you move. The honest part here is picking the right one: most people overestimate. A few gym sessions a week is moderate, not very active. If your job is a desk and your evenings are a couch, you are sedentary even if you train hard three times a week.

Choose the level that matches a normal week, then multiply. When you are between two levels, round down. Overstating activity is the most common reason a plan stalls, because it inflates your calorie target from the start.

• Sedentary (little or no exercise): BMR x 1.2
• Lightly active (light exercise 1 to 3 days a week): BMR x 1.375
• Moderately active (moderate exercise 3 to 5 days): BMR x 1.55
• Very active (hard exercise 6 to 7 days): BMR x 1.725
• Extra active (physical job or two-a-day training): BMR x 1.9

A worked example, start to finish

Take a 30-year-old man who is 5 feet 10 inches (178 cm) and weighs 175 pounds (about 79.4 kg), training moderately three to four days a week.

First the BMR: 10 x 79.4 = 794, plus 6.25 x 178 = 1,112.5, minus 5 x 30 = 150, plus 5 for being male. That is 794 + 1,112.5 - 150 + 5 = 1,761.5, which rounds to about 1,762 calories. That is what he would burn doing nothing all day.

Now the activity factor. Moderately active means multiply by 1.55: 1,762 x 1.55 = 2,731 calories. That is his TDEE, the calories that hold his weight steady. From here, every goal is a shift up or down from 2,731.

Use your TDEE to lose, maintain, or gain

One pound of body fat stores roughly 3,500 calories, so a daily gap of about 500 calories adds up to close to a pound a week. That rule of thumb is where deficit and surplus targets come from. It is an approximation, not a law: water weight and metabolic changes make the scale bounce around week to week.

To lose weight, subtract 500 from your TDEE. Our example man eats about 2,231 calories to lose roughly a pound a week. To maintain, eat at your TDEE, 2,731. To gain, add a surplus, but keep it modest: 250 to 500 over TDEE, so about 3,000 to 3,200, adds muscle without piling on excess fat. Aggressive surpluses mostly add fat.

Recalculate as your weight changes. TDEE falls as you get lighter, so a deficit that worked at 175 pounds is smaller at 160. Re-run the numbers every 8 to 12 pounds, or whenever progress clearly stalls for two to three weeks.

• Lose weight: TDEE minus 500 (about 1 lb per week)
• Maintain: eat at TDEE
• Gain: TDEE plus 250 to 500 for lean gains
• Do not drop below about 1,500 calories (men) or 1,200 (women) without medical supervision

Turn calories into macros

A calorie target tells you how much to eat; macros tell you what. The one that matters most for body composition is protein, which protects muscle in a deficit and keeps you full. A common target is about 0.7 to 1 gram per pound of body weight. Fat should stay high enough for hormone health, usually 0.3 to 0.4 grams per pound, and carbohydrates fill whatever calories remain to fuel training.

For the example man cutting on 2,231 calories: set protein around 150 grams (600 calories), fat around 60 grams (540 calories), and the remaining 1,091 calories as carbohydrates, about 273 grams. Protein and carbs carry 4 calories per gram and fat carries 9, which is why the fat number looks small but eats up a lot of the budget.

• Protein: 0.7 to 1 g per lb of bodyweight, at 4 cal/g
• Fat: 0.3 to 0.4 g per lb, at 9 cal/g
• Carbs: the calories left over, at 4 cal/g
• Set protein first, then fat, then let carbs fill the rest

Common mistakes

TDEE math is simple, but a few predictable errors send people off course. Watching for these keeps your estimate honest and your results on track.

• Overrating your activity level. Picking very active when you sit at a desk inflates your target by hundreds of calories and stalls progress before you start.
• Treating the number as exact. Formulas estimate the average person; your real burn can be 5 to 10 percent higher or lower. Use the scale over two to three weeks as the true test and adjust.
• Never recalculating. As you lose weight your TDEE drops, so a deficit slowly shrinks to maintenance if you never update it.
• Not tracking intake honestly. Untracked bites, oils, and drinks quietly erase a 500-calorie deficit. The math only works if the food log is accurate.
• Cutting too hard. Slashing far below TDEE costs muscle, energy, and adherence, and rarely beats a steady 500-calorie deficit over time.

Two more worked examples with different inputs

The main example was a 30-year-old man, so here are two with different numbers. First, a 42-year-old woman who is 5 feet 5 inches (165.1 cm) and weighs 150 pounds (68.0 kg), exercising lightly one to three days a week. Her BMR is 10 x 68.04 + 6.25 x 165.1 - 5 x 42 - 161, which is about 1,341 calories. Lightly active means x 1.375, so her TDEE is about 1,844 calories.

Second, a 55-year-old man in metric units: 182 cm, 92 kg, with a desk job and no regular exercise. His BMR is 920 + 1,137.5 - 275 + 5 = 1,787.5, or about 1,788. Sedentary means x 1.2, so his TDEE is about 2,145 calories.

Notice what happens to the usual advice of subtracting 500 for weight loss. For the woman that lands at 1,344, only about 150 above the 1,200 floor often quoted for unsupervised dieting, and a gap of 27 percent of her maintenance. A 250-calorie cut, which is 1,594, is gentler and far easier to hold. The man's 500-calorie cut leaves 1,645, which is 23 percent of his TDEE. The same absolute number is a very different squeeze depending on where you start.

When Mifflin-St Jeor misses: using lean body mass

Mifflin-St Jeor assumes a typical body composition for your height and weight. It cannot tell a lean, muscular person from a sedentary person of the same size, even though muscle and the organs it supports burn more energy than fat tissue. If you know your body-fat percentage from a reliable measurement, the Katch-McArdle equation uses lean mass directly: BMR = 370 + 21.6 x lean body mass in kilograms.

Compare the two on an athlete who is 185 cm, 90 kg, 28 years old, and 10 percent body fat. His lean mass is 81 kg, so Katch-McArdle gives 370 + 1,749.6 = about 2,120 calories. Mifflin-St Jeor gives 900 + 1,156.25 - 140 + 5 = about 1,921. The gap of roughly 198 calories before the activity multiplier is enough to matter.

The error runs the other way for someone with a high body-fat percentage. A 30-year-old man who is 178 cm and 100 kg at 30 percent body fat has 70 kg of lean mass, giving a Katch-McArdle BMR of 1,882 against about 1,968 from Mifflin-St Jeor. Neither formula is a lab measurement, and consumer body-fat estimates can be off by several points, so use whichever estimate matches your real-world results.

Do not count your workouts twice

The activity multiplier already contains an allowance for exercise. If you choose moderately active (x 1.55) and then add the calories burned in each gym session on top, you have counted the same effort twice. That mistake alone can inflate a target by several hundred calories.

There are two consistent ways to work. Either use a multiplier that matches your whole week and do not add anything, or use the sedentary factor of 1.2 and add your tracked exercise separately. For the second method, estimate session cost as MET x body weight in kilograms x hours, which gives total calories including what you would burn at rest anyway. Walking at a moderate pace of about 3 mph is rated at roughly 3.5 METs, so one hour for a 79.4 kg person is about 278 calories in total, or about 198 above resting.

Run the numbers on the original man. His sedentary figure is 1,762 x 1.2 = 2,114. Four 300-calorie net workouts a week add about 171 a day, for roughly 2,286, well below the 2,731 from the moderate multiplier. That gap is a sign that the moderate label may be generous for a few hour-long sessions, and it explains why many people stall when they trust the multiplier alone.

Calibrating the estimate with real data

The surest way to tighten any TDEE estimate is to measure it from your own results. Log your food accurately for two to three weeks and weigh yourself the same way each morning, then compare the trend. If your weight is flat, your average intake is your maintenance. If it moved, convert the change into a daily number using the 3,500 calories per pound approximation.

Suppose you eat an average of 2,300 calories and lose 1.5 pounds in 21 days. That is about 5,250 calories of deficit spread over 21 days, or 250 a day, so your estimated TDEE is 2,300 + 250 = 2,550. If the formula said 2,731, trust the 2,550 and plan from there.

Be careful about noise. A single weigh-in can swing a pound or more from water, sodium, digestion and, for some, the menstrual cycle, so compare weekly averages rather than individual days. The 3,500 figure is also a rough guide, because the energy content of weight change depends on whether you are losing fat, water or lean tissue. Treat the result as a calibrated estimate and update it whenever your routine changes.

Setting the pace of loss

The CDC describes gradual weight loss of about 1 to 2 pounds a week as the range associated with keeping it off, but the right pace depends on your size. Someone with a lot to lose can run a larger deficit without much trouble. Someone close to their goal weight has less room, and a deficit that is a large share of a small TDEE tends to cost muscle, sleep quality and training performance.

A useful habit is to think of the deficit as a percentage of your TDEE, not as 500 by default. On a TDEE of 2,731, a 500-calorie deficit is 18 percent, and a 250-calorie one is 9 percent. A 20 percent cut would be about 546 calories, leaving about 2,185, which lands near the usual 500 rule for this particular person. For the woman above, 20 percent of 1,844 is about 369, so her sensible target is closer to 1,475 than to 1,344.

Plan breaks as well as cuts. Spending a few weeks at maintenance after a long deficit gives you a chance to recheck your numbers and recover training quality, and it makes the next phase more productive than grinding downward without a pause.

People this formula was not built for

The Mifflin-St Jeor equation came from measurements of healthy adults across a broad age range, roughly 19 to 78. It was not designed for growing children and teenagers, pregnant or breastfeeding women, or people with conditions that change metabolism, such as thyroid disease or some other endocrine disorders. For those groups, a standard estimate can be well off the real need, and a clinician or registered dietitian can set targets based on your situation.

Certain medications raise or lower appetite and energy use, and people recovering from illness or injury often need more energy than a sedentary multiplier suggests. Anyone with a history of disordered eating should avoid calorie-counting and deficit targets unless a professional is involved, because the numbers themselves can become a trigger.

Older adults deserve a note too. Muscle tends to decline with age, which lowers real energy needs below what a young-adult activity factor implies, while protein needs do not fall. The practical result is that calories become tighter while the importance of protein and resistance training rises.