TDEE Calculator

What TDEE is, and why the number you guess is usually too high

TDEE is total daily energy expenditure: every calorie your body spends in 24 hours. Four things make it up. Your basal metabolic rate, the cost of simply being alive, is the largest slice and usually lands somewhere around 60 to 70 percent of the total. The thermic effect of food, the energy used to digest what you eat, takes roughly a tenth. Deliberate exercise is the part everyone thinks about and, for most people who are not athletes, the smallest. The remainder is everything else you do while awake: walking to the store, standing, carrying, fidgeting. That last category varies enormously between two people of the same size, and it is the main reason two colleagues with identical height, weight and age can need noticeably different amounts of food.

This page estimates your BMR with the Mifflin-St Jeor equation, then multiplies it by an activity factor between 1.2 and 1.9. Those multipliers are a long-standing convention rather than figures from a single study, and the factor is where people go wrong. Choosing moderately active when lightly active is honest adds roughly 250 to 350 calories to the answer for most adults, which is more than half of a 500 calorie deficit. An hour in the gym is about four percent of your day, so training three times a week moves the needle far less than the word active suggests.

Which activity level fits you, and which target to use

Pick the row that describes an ordinary week, not your best week. If two rows both sound plausible, take the lower one: it is far easier to notice that you are losing weight faster than planned and add food back than it is to work out why a deficit that was never really a deficit is not working.

The result then gives you three figures and a macro split:

• Maintenance, the headline TDEE: holding your weight while you train, recovering from a long diet, or simply learning what a normal day of food looks like for you.
• The fat loss target: the headline figure minus 500 kcal. Harvard Health Publishing describes eating 500 to 1,000 calories below maintenance as the way to lose 1 to 2 pounds a week, and the CDC describes that pace as the one people are more likely to keep off.
• The muscle gain target: the headline figure plus 300 kcal, meant to go with resistance training.
• The macro split: protein, carbohydrate and fat in grams, for when your app asks for macro goals rather than one calorie number. It is set at 1.6 g of protein per kilogram of body weight and 25 percent of calories from fat, with the rest as carbohydrate.

How to find your maintenance calories

1. Choose your units. The calculator opens in imperial, with feet, inches and pounds. Switch to metric for centimeters and kilograms; the result is identical either way.
2. Enter sex, age, height and weight. The equation was built around male and female coefficients, so choose the one that matches your physiology rather than any other consideration.
3. Pick an activity level from the five cards, using the table above and erring low.
4. Read the large figure. That is your estimated maintenance intake in calories per day.
5. Look at the bar underneath. The blue segment is your resting burn, the orange segment is everything the activity factor added, and the dashed lines mark the fat loss and muscle gain targets.

How to correct the estimate after two weeks

A calculator cannot know your individual metabolism or how much you move without noticing. What it gives you is a starting point to test against two weeks of your own numbers.

1. Eat the target consistently for fourteen days. Weigh your food rather than guessing portions for at least the first week.
2. Weigh yourself several mornings a week under the same conditions, after using the bathroom and before breakfast.
3. Compare the average of week two against the average of week one. Never compare single days: a salty dinner or a missed bowel movement moves the scale by more than a week of fat loss does.
4. If you wanted to lose and the average has not moved, the estimate was too high for you. A small step down, 100 to 200 kcal, and another two weeks tests that without overshooting. If you are losing faster than the 1 to 2 pounds a week the CDC describes as a gradual, steady pace, the target is lower than it needs to be.
5. A lighter body burns less, so a target that worked at the start will eventually become your new maintenance. Re-enter your weight every ten pounds or so (four to five kilograms) to see the new figure.

Getting the number into the app you actually use

• Calorie tracking apps: most let you override the goal the app suggested. Look for a custom or manual goal setting and type the figure from this page in, rather than letting the app work out its own target from a weekly weight loss rate.
• Apps that want macros: enter the protein, carbohydrate and fat grams from the split on this page. Some apps accept percentages instead, which are shown next to each value.
• Keeping a record: nothing is saved between visits, so write the figures down before you close the tab.

Why watches and calorie apps show a different number

Part of the gap is the resting equation: the BMR calculator page compares Mifflin-St Jeor with Harris-Benedict, Katch-McArdle and Cunningham. The rest comes from how a device or an app does its accounting.

• Fitness trackers and smartwatches do not use an equation alone. They estimate active energy from heart rate and motion and add a resting estimate of their own, then report a rolling daily total that moves as you move.
• Calorie apps often take a different route entirely: you tell them how fast you want to lose weight, and they work backward to a goal, then credit logged workouts on top of it. That is a coherent system, but it is not the same system as a fixed TDEE that already includes your training. Picking one and staying with it matters more than which one you pick.

Limits worth knowing before you act on the number

This is a general information tool, not medical advice, and it cannot account for pregnancy, breastfeeding, thyroid or metabolic conditions, medication that affects appetite or weight, a history of disordered eating, or growth in children and teenagers. Talk to a doctor or a registered dietitian before making significant changes to what you eat.

The fat loss target is plain subtraction, so for a small or sedentary person it can come out very low. Harvard Health Publishing says intake should not fall below 1,200 calories a day for women or 1,500 for men except under the supervision of a health professional. When TDEE minus 500 falls under that floor, the card says so and does not offer the figure as a target. When it is above the floor but below your BMR, the figure is shown with a note that a 500 kcal step is steep for you.

The common rule that 3,500 kcal equals a pound of fat overstates what happens over months. A 2011 paper in The Lancet, led by a researcher at the US National Institutes of Health, points out that the rule ignores how resting metabolism and the energy cost of activity both fall as weight comes off; its model puts only half of the eventual weight change in the first year.