How to Calculate Your TDEE and Daily Calorie Needs
To calculate your TDEE (total daily energy expenditure), first estimate your BMR (basal metabolic rate) with the Mifflin-St Jeor equation: 10 × weight in kg + 6.25 × height in cm - 5 × age in years, then add 5 for men or subtract 161 for women. Next, multiply that BMR by an activity factor between 1.2 (sedentary) and 1.9 (extra active). For example, a 30-year-old man who weighs 180 lb, stands 5'10" and trains four days a week has a BMR of about 1,782 and a TDEE of about 2,762 calories a day.
TDEE is the number of calories you burn in a day, so eating near it holds your weight steady, eating below it produces weight loss, and eating above it produces weight gain. This guide walks through each step with worked examples, shows how to pick a target for your goal, explains why the popular 3,500-calorie rule overpromises, and covers how to test your estimate against real results. You can check every number with our Calorie Calculator.
Step 1: Estimate Your BMR
Your basal metabolic rate is the energy your body uses at rest to keep you alive: breathing, circulating blood, maintaining body temperature and repairing cells. The National Academies of Sciences, Engineering, and Medicine report that resting energy expenditure typically accounts for 60 to 70 percent of total daily energy expenditure, with the thermic effect of food (the energy used to digest what you eat) adding roughly 10 percent and physical activity making up the rest.
The Mifflin-St Jeor equation, published in 1990 from measurements on 498 healthy adults, is the formula most calculators use. In that study the older 1919 Harris-Benedict equations overestimated measured resting energy expenditure by 5 percent. A 2005 systematic review by the American Dietetic Association found that Mifflin-St Jeor predicted resting metabolic rate within 10 percent of the measured value for more people than the other common equations, though it also warned of noteworthy errors for individuals.
The Mifflin-St Jeor formula
Men: BMR = (10 × weight in kg) + (6.25 × height in cm) - (5 × age in years) + 5
Women: BMR = (10 × weight in kg) + (6.25 × height in cm) - (5 × age in years) - 161
The two versions differ only in the final constant (+5 for men, -161 for women), which reflects the average difference in lean body mass between the sexes.
Example: BMR for a man and a woman
A 30-year-old man who weighs 180 lb (81.6 kg) and is 5'10" (177.8 cm):
BMR = (10 × 81.6) + (6.25 × 177.8) - (5 × 30) + 5
BMR = 816 + 1,111.25 - 150 + 5
BMR = 1,782 calories per day
A 28-year-old woman who weighs 140 lb (63.5 kg) and is 5'5" (165.1 cm):
BMR = (10 × 63.5) + (6.25 × 165.1) - (5 × 28) - 161
BMR = 635 + 1,031.9 - 140 - 161
BMR = 1,366 calories per day
These figures are what each person would burn lying still all day, so they are not eating targets.
Converting pounds and inches
Multiply pounds by 0.4536 to get kilograms and inches by 2.54 to get centimeters. The man above is 180 × 0.4536 = 81.6 kg and 70 × 2.54 = 177.8 cm. The Calorie Calculator accepts either unit system, and our BMI Calculator uses the same weight and height inputs if you want to see where you fall on that scale too.
Step 2: Multiply by Your Activity Factor
BMR covers only the energy you burn at rest. To estimate TDEE, multiply it by an activity factor that stands in for everything else: walking, exercise, fidgeting, standing and digesting food.
TDEE = BMR × activity factor
| Activity level | Multiplier | Typical week |
|---|---|---|
| Sedentary | 1.2 | Desk job, little or no exercise |
| Lightly active | 1.375 | Light exercise 1 to 3 days per week |
| Moderately active | 1.55 | Moderate exercise 3 to 5 days per week |
| Very active | 1.725 | Hard exercise 6 to 7 days per week |
| Extra active | 1.9 | Very hard daily training plus a physical job |
These five factors are long-standing rules of thumb, not measurements of your body, and they are the biggest source of error in the whole calculation. Most people rate themselves too high. If you work out three times a week but sit the rest of the day, "lightly active" is usually the honest choice.
Example: TDEE for the same two people
The man (BMR 1,782) trains at the gym four days a week, so he is moderately active:
TDEE = 1,782 × 1.55 = 2,762 calories per day
The woman (BMR 1,366) does yoga twice a week and walks most days, so she is lightly active:
TDEE = 1,366 × 1.375 = 1,878 calories per day
| Person | BMR | Activity factor | TDEE |
|---|---|---|---|
| Man, 30, 180 lb, 5'10" | 1,782 | 1.55 | 2,762 |
| Woman, 28, 140 lb, 5'5" | 1,366 | 1.375 | 1,878 |
Eating at these numbers should hold each person's current weight, give or take the error built into any estimate.
Step 3: Set Your Calorie Target
Once you have your TDEE, your goal decides how far above or below it you eat.
Losing weight
The usual starting point is a deficit of about 500 calories per day. The old rule says a pound of body fat holds about 3,500 calories, so 500 fewer calories a day should mean about 1 lb lost per week. For the man in our example:
Weight loss target = 2,762 - 500 = 2,262 calories per day
The same cut is much tighter for the woman: 1,878 - 500 = 1,378, only 12 calories above her BMR of 1,366. A smaller deficit of 250 calories (1,628) is a gentler place to start for someone her size.
Treat the 3,500-calorie rule as a rough guide for the first weeks only. It assumes your energy needs stay fixed, but they fall as you get lighter, so the same deficit produces less loss over time. NIH researchers built the Body Weight Planner for this reason, and their model shows that weight responds slowly to a change in intake, with a half time of about a year. For pace, the CDC says people who lose weight gradually and steadily, about 1 to 2 pounds a week, are more likely to keep it off than people who lose it faster.
Building muscle
Gaining muscle takes a calorie surplus. A 2019 narrative review of bodybuilding nutrition suggested a surplus of roughly 10 to 20 percent above maintenance for novice and intermediate lifters, and advised advanced lifters to be more conservative. For our man, 10 percent is about 276 calories, which gives a target near 3,038 calories per day, and 20 percent is about 552 calories, or 3,314. Start at the low end and adjust to how your weight moves.
Maintaining weight
Eat at or near your TDEE and judge results by the weekly average. Daily weight swings of a few pounds from water, salt and food still in your system are normal and say little about fat gain or loss.
Is 1,200 Calories a Day Enough?
Diet plans often quote 1,200 calories as a fixed target. It is worth checking against your own numbers first. In our examples, 1,200 is 166 calories below the woman's BMR and 582 below the man's. A flat number ignores body size, age and activity, which is exactly what a TDEE-based target corrects.
Many programs treat 1,200 calories for women and 1,500 for men as a lower limit for dieting without supervision. These are common rules of thumb, not official limits. The National Institute of Diabetes and Digestive and Kidney Diseases describes very low-calorie diets, which supply about 800 calories a day or less, as diets supervised by a health care professional. If your calculated target lands near those levels, talk to a doctor or registered dietitian before you start.
Why Your Metabolism Adapts to Dieting
As you lose weight, your body burns less than the smaller body alone would predict. Researchers call this metabolic adaptation or adaptive thermogenesis.
The clearest example is a follow-up of contestants from "The Biggest Loser." Of the 16 contestants studied, 14 returned six years later. They had lost an average of 58.3 kg during the 30-week competition and regained 41.0 kg since. Their resting metabolic rate was 704 calories a day below baseline, and after adjusting for changes in body composition and age, it was about 499 calories a day lower than expected. That group lost weight far faster and further than most dieters do, so expect a smaller effect from a moderate diet.
Planned breaks may soften the effect. In the MATADOR trial, 51 men with obesity were randomized to diet at 67 percent of their maintenance needs for 16 weeks, either continuously or in two-week blocks separated by two weeks of eating at maintenance. Among the 36 who completed the protocol, resting energy expenditure fell by about 179 calories a day with continuous dieting and about 86 with the two-week blocks after adjusting for body composition, and the block group lost more weight (14.1 kg versus 9.1 kg) and more fat (12.3 kg versus 8.0 kg). The block group took 30 weeks in total rather than 16, and the study was small, so this is encouraging evidence rather than a rule.
In practice: keep the deficit moderate, consider a week or two at maintenance during a long diet, and recalculate your TDEE as your weight changes.
How to Check and Adjust Your Estimate
Your calculated TDEE is a starting estimate. To test it:
- Track your food for at least two weeks, weighing portions with a kitchen scale instead of eyeballing them.
- Weigh yourself at the same time each morning and compare weekly averages, not single days.
- After two to three weeks, compare the trend with your goal. If you aim to lose a pound a week on a 500-calorie deficit and your weekly average is not moving, either your true TDEE is lower than calculated or your logged portions are too small.
- Change intake in small steps of 100 to 200 calories instead of large cuts.
- Recalculate after every 10 to 15 lb of weight change, because a lighter body burns less.
Pair your result with our Macro Calculator to split the calories into protein, carbs and fat, use the Weight Loss Calculator to see how long a deficit takes to reach a goal weight, and read Macros Explained for what each nutrient does. Our health calculators cover related numbers such as BMI and heart rate zones.
Frequently Asked Questions
What is the difference between BMR and TDEE?
BMR is the energy your body uses at complete rest. TDEE is your total burn for the day, which adds the thermic effect of food and all movement and exercise on top of BMR. The National Academies report that resting energy expenditure typically makes up 60 to 70 percent of the total, so TDEE is always higher than BMR, and for most people it is 1.2 to 1.9 times BMR.
How accurate is a TDEE calculator?
It gives a good starting estimate, not an exact answer. A 2005 systematic review found the Mifflin-St Jeor equation predicts resting metabolic rate within 10 percent of the measured value for more people than the other common equations, but it also found noteworthy errors for individuals. The activity multiplier adds a second guess, so confirm your number with two to three weeks of tracking.
How many calories below my TDEE should I eat to lose weight?
Most people start with 250 to 500 calories below TDEE. The CDC says a gradual pace of about 1 to 2 pounds a week is more likely to be kept off than faster loss. Real progress usually slows after the first weeks because your body burns less as you get lighter, so adjust your target as your weight changes.
Should I eat back the calories I burn during exercise?
Not if you chose an activity multiplier, because exercise is already counted in your TDEE and eating it back double counts it. Do not rely on a watch's calorie number either. In a Stanford study of seven wrist-worn devices, the median error for energy expenditure ranged from 27 percent to 93 percent depending on the device, and none came in under 20 percent.
How many calories above my TDEE do I need to build muscle?
A 2019 narrative review of bodybuilding nutrition suggested a surplus of about 10 to 20 percent above maintenance for novice and intermediate lifters, with a more conservative surplus for advanced lifters. For a TDEE of 2,762, that is roughly 276 to 552 extra calories a day.
Sources
- Mifflin MD, St Jeor ST, et al. A new predictive equation for resting energy expenditure in healthy individuals, American Journal of Clinical Nutrition, 1990.
- 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.
- National Academies of Sciences, Engineering, and Medicine. Dietary Reference Intakes for Energy, 2023, chapter on factors affecting energy expenditure (share of energy expenditure from resting metabolism and the thermic effect of food).
- CDC. Steps for Losing Weight (gradual loss of about 1 to 2 pounds a week).
- Hall KD, et al. Quantification of the effect of energy imbalance on bodyweight, The Lancet, 2011, and the NIDDK Body Weight Planner.
- NIDDK. Very low-calorie diet (definition).
- Fothergill E, et al. Persistent metabolic adaptation 6 years after "The Biggest Loser" competition, Obesity, 2016.
- Byrne NM, et al. Intermittent energy restriction improves weight loss efficiency in obese men: the MATADOR study, International Journal of Obesity, 2018.
- Iraki J, Fitschen P, Espinar S, Helms E. Nutrition recommendations for bodybuilders in the off-season: a narrative review, Sports, 2019.
- Shcherbina A, et al. Accuracy in wrist-worn, sensor-based measurements of heart rate and energy expenditure in a diverse cohort, Journal of Personalized Medicine, 2017.
All sources were checked in September 2026.