TDEE Calculator: Find Your Maintenance Calories

What TDEE actually means

Think of TDEE as your body’s daily running cost. It has four parts, and most people are surprised by how the split works out.

• Basal metabolic rate, or BMR. The calories you burn lying still, awake, doing nothing. It covers breathing, circulation, brain activity, and keeping your body at the right temperature. For most adults this is 60 to 70 percent of the total.
• Digesting food. Breaking down and storing what you eat costs about 10 percent of the calories in the meal. Protein costs the most to digest, which is one reason high-protein diets help with fullness.
• Everyday movement. Walking to the car, cooking, fidgeting, standing at your desk. Researchers call this non-exercise activity, and it varies more from person to person than any other part. It can be a few hundred calories a day for someone who sits most of the time, and well over a thousand for someone on their feet all day.
• Exercise. Planned workouts. For most people who train three or four times a week, this is the smallest slice, usually 5 to 10 percent of the day’s total.

Add the four together and you have your TDEE. If you eat roughly that many calories, your weight holds steady. Eat less and you lose. Eat more and you gain. That is the whole idea behind every diet that has ever worked, whether it calls itself keto, intermittent fasting, or anything else.

How this calculator works out your number

The calculator starts by estimating your BMR with the Mifflin-St Jeor equation, published in 1990 by Mifflin and colleagues after measuring the resting metabolism of nearly 500 adults. In 2005 the Academy of Nutrition and Dietetics compared the common formulas against lab measurements and found Mifflin-St Jeor was the most reliable, landing within 10 percent of the real figure for most people. It has been the standard in dietetics ever since.

The formula itself is simple. For men, BMR is 10 times your weight in kilograms, plus 6.25 times your height in centimeters, minus 5 times your age, plus 5. For women it is the same but you subtract 161 at the end instead of adding 5. The calculator converts pounds and feet for you if you use US units.

Then it multiplies your BMR by an activity factor:

If you enter a body fat percentage, the calculator switches to the Katch-McArdle formula, which works from your lean body mass instead of your total weight. It is a better fit for people who are very muscular or carry a high body fat percentage, because two people of the same weight and height can have very different amounts of calorie-burning muscle. If you do not know your body fat, leave the box empty. A guess is worse than the standard formula.

How many calories should you eat a day?

This is the question most people actually came here to answer, so here is the plain version.

To stay the same weight

Eat your TDEE. For an average American woman that works out somewhere between 1,800 and 2,200 calories, and for an average man between 2,200 and 3,000, which matches the ranges in the Dietary Guidelines for Americans. The NHS gives a similar rule of thumb for UK adults: about 2,000 for women and 2,500 for men. Your own number depends on your size, age, and how much you move, which is exactly what the calculator adjusts for.

To lose weight

Eat below your TDEE. A deficit of about 500 calories a day leads to roughly one pound of loss a week, and that is the pace most health bodies recommend, including the CDC, which advises a steady one to two pounds a week. A smaller deficit of 250 calories is slower but much easier to keep up, and it preserves more muscle. The calculator shows both.

The old rule that 3,500 calories equals one pound of fat is a rough guide, not a law. As you lose weight your TDEE drops too, because a smaller body burns less, so progress slows over time. The National Institutes of Health built the Body Weight Planner to model that slowdown. The practical lesson is simple: recalculate every 10 pounds or so.

To gain weight or build muscle

Eat above your TDEE, but not by much. A surplus of 250 to 500 calories a day supports muscle growth when it is paired with strength training. Go higher than that and most of the extra ends up as fat, not muscle.

Picking your activity level honestly

This is where most TDEE calculations go wrong, and it is not the formula’s fault. People consistently overrate how active they are. If you lift weights for 45 minutes three times a week but sit for the other 15 waking hours, you are lightly active, not moderately active. A nurse or a warehouse worker who never sets foot in a gym may be very active just from the job.

A good test: pick the level you think fits, then pick the one below it. Use the lower number for three weeks and watch the scale. If you are losing faster than you planned, move up. Starting low and adjusting upward is far less frustrating than starting high and wondering why nothing is happening.

Step counts help too. Under 5,000 steps a day with no training is sedentary. Around 7,500 to 10,000 with a few workouts a week is moderately active. If you want to know what those steps are worth in calories, our guide to how many steps it takes to burn 1,000 calories breaks it down by weight and pace.

How accurate is a TDEE calculator?

Honest answer: good enough to start with, not good enough to trust blindly. In lab studies, Mifflin-St Jeor lands within 10 percent of measured resting metabolism for about 7 in 10 people. That means if the calculator says 2,000, your real number is probably somewhere between 1,800 and 2,200. The activity multiplier adds more uncertainty on top, because it is a judgment call.

The fix is not a better calculator. It is feedback. Weigh yourself a few mornings a week under the same conditions, average each week, and compare. If the weekly average is flat while you are eating at your calculated TDEE, the number is right. If you are gaining, your real TDEE is lower, so take 150 to 200 off. If you are losing, add some back. After a month of this you will know your maintenance calories better than any formula can tell you.

Fitness watches are not a shortcut here. Studies comparing wrist trackers to lab measurements find they can be off by 20 percent or more on calories burned, in both directions. Use the trend on the watch, not the daily number.

What the BMI and ideal weight figures mean

The calculator also shows your body mass index and an ideal weight range, because most people want to know where they stand, not just how much to eat. Treat both as rough context. BMI is your weight divided by your height squared. It is a quick screening number used by the NHS and the CDC, and the healthy range for adults is 18.5 to 24.9. It cannot tell muscle from fat, so athletes often score as overweight while being very lean, and older adults can sit in the healthy range while carrying too little muscle.

The ideal weight range comes from four formulas, Hamwi, Devine, Robinson, and Miller, that were built decades ago for drug dosing and insurance tables. They use only your height and sex. They give a useful ballpark, and they are the same ones most calculator sites use, but they are not a goal to chase. A healthy weight for you depends on your build, your body fat, and how you feel and perform, which no height formula can see.

Why TDEE differs for women, men, and older adults

Men usually have a higher TDEE than women of the same weight because they carry more muscle, and muscle burns more at rest than fat does. That is why the formula adds 5 for men and subtracts 161 for women. It is a population average, so a very muscular woman can easily out-burn a sedentary man.

Age lowers TDEE for two reasons. Muscle mass tends to fall from the 30s onward unless you train to keep it, and people usually move less as they get older. The formula takes off 5 calories for every year of age, which works out to roughly 50 fewer calories per decade at rest, plus whatever activity you have lost. The good news is that strength training two or three times a week slows both of those changes considerably.

Pregnancy, breastfeeding, thyroid conditions, and some medications all change calorie needs in ways a general calculator cannot capture. In those cases, use the number as a conversation starter with your doctor or a registered dietitian, not as a target.

Mistakes that make the number useless

• Eating back exercise calories twice. Your activity level already includes your workouts. If you also add the calories your watch says you burned, you are counting them a second time.
• Treating it as exact. 2,147 calories is not more correct than 2,150. Round it, and think in ranges.
• Never recalculating. Lose 15 pounds and your TDEE has changed. Run the numbers again after every 10 pounds or any big change in routine.
• Cutting too hard. A 1,000-calorie deficit feels productive for a week, then hunger, fatigue, and muscle loss catch up. Slower almost always wins over six months.
• Ignoring protein. A deficit without enough protein loses muscle along with fat. The macro table above sets protein at about 0.7 grams per pound of body weight, which is within the range most sports nutrition bodies recommend for people who train.

Putting the number to work

Once you have your TDEE, the rest is logistics. Build meals around foods that keep you full for the calories: protein at every meal, vegetables, fruit, and whole grains. Simple breakfasts help more than people expect. If you want one that is easy to count and keeps you full until lunch, see what happens when you eat oats every day. On the activity side, you do not need extreme sessions. Our guide to easy exercises that burn 1,000 calories a day shows how to spread movement across a week in a way that is realistic to keep up.

Give any new calorie target three weeks before you judge it. That is long enough for water weight to settle and for a real trend to show.

When to talk to a doctor

Check with a doctor before changing your calories if you have diabetes, kidney disease, heart disease, a history of disordered eating, or if you take medication that affects appetite or blood sugar. Also get advice if you are losing weight without trying, if you cannot lose weight on a sensible deficit after two months, or if dieting leaves you dizzy, exhausted, or constantly cold. Those can be signs of something that a calculator cannot fix.

Frequently asked questions