TDEE Calculator

A TDEE calculator estimates the calories you burn in a day by multiplying your basal metabolic rate (BMR) by an activity factor. Take a 35-year-old woman who is 5 ft 6 in, weighs 150 lb and exercises 3 to 5 days a week. The Mifflin-St Jeor equation gives her a BMR of about 1,392 calories, and 1,392 × 1.55 ≈ 2,158 calories a day.

How to use the TDEE calculator

1. Pick a BMR formula. Mifflin-St Jeor is the default. Katch-McArdle needs your body fat percentage.
2. Choose US or metric units and enter your sex, age, height and weight.
3. Pick the activity level that matches a typical week, not your best week.
4. Read your TDEE at the top of the results, then check the calorie targets, the table for every activity level and the comparison of all three formulas.
5. Open Show steps to see the full working with your numbers, or use Copy result to save it.

What TDEE and BMR mean

Your basal metabolic rate (BMR) is the energy your body uses at complete rest, just to breathe, circulate blood and keep your organs working. The studies behind these equations measured resting energy expenditure, which is very close to BMR, so the two terms are used together here.

Total daily energy expenditure (TDEE) adds everything else: walking, work, exercise and digesting food. It is the number of calories that would keep your weight about the same, so it is often called your maintenance calories. The calculator uses one simple relationship:

TDEE = BMR × activity multiplier

BMR formulas: Mifflin-St Jeor, Harris-Benedict and Katch-McArdle

In every equation below, W is weight in kilograms, H is height in centimeters and A is age in years. If you use pounds and inches, convert first: 1 lb = 0.45359237 kg and 1 in = 2.54 cm. The calculator does this for you.

Mifflin-St Jeor equation (1990)

• Men: BMR = 10W + 6.25H − 5A + 5
• Women: BMR = 10W + 6.25H − 5A − 161

Mifflin, St Jeor and colleagues built this equation from measurements of 498 healthy adults aged 19 to 78, including people at a normal weight and people with obesity. In the same study, the original 1919 Harris-Benedict equation overestimated measured resting needs by about 5%. Mifflin-St Jeor is the calculator’s default.

Revised Harris-Benedict equation (1984)

• Men: BMR = 88.362 + 13.397W + 4.799H − 5.677A
• Women: BMR = 447.593 + 9.247W + 3.098H − 4.330A

Roza and Shizgal re-fit the original Harris-Benedict data in 1984, adding subjects with a wider age range. They reported that the equations estimate resting needs in healthy people to within about ±14%. Because the original version tends to run high, it usually gives a result a little above Mifflin-St Jeor for the same person.

Katch-McArdle equation

• Lean body mass (LBM) = W × (1 − body fat % ÷ 100)
• BMR = 370 + 21.6 × LBM

Katch-McArdle, from the exercise physiology textbook by McArdle, Katch and Katch, ignores sex, age and height. It uses only lean body mass, the part of your weight that is not fat. It suits people who know their body fat percentage reasonably well. Each kilogram of lean mass adds 21.6 calories, so a body fat estimate that is off by a few points can shift the BMR noticeably.

Activity multipliers for TDEE

The multipliers below are a convention used by most TDEE calculators. They are rough estimates, not measured values, and they are the least certain part of the calculation. If you are unsure between two levels, the lower one is usually the safer guess, because many people overestimate how active they are.

Worked TDEE examples

Example 1: Mifflin-St Jeor, US units

A 35-year-old woman is 5 ft 6 in tall, weighs 150 lb and is moderately active.

1. Convert: 150 × 0.45359237 ≈ 68.04 kg, and 66 in × 2.54 = 167.64 cm.
2. BMR = 10(68.04) + 6.25(167.64) − 5(35) − 161 ≈ 680.4 + 1,047.8 − 175 − 161 ≈ 1,392 calories.
3. TDEE = 1,392.1 × 1.55 ≈ 2,158 calories a day.

Example 2: revised Harris-Benedict, same man two ways

A 40-year-old man is 5 ft 10 in (177.8 cm), weighs 180 lb (about 81.65 kg) and is sedentary.

1. Revised Harris-Benedict: 88.362 + 13.397(81.65) + 4.799(177.8) − 5.677(40) ≈ 88.4 + 1,093.8 + 853.3 − 227.1 ≈ 1,808 calories.
2. TDEE = 1,808.4 × 1.2 ≈ 2,170 calories a day.
3. For comparison, Mifflin-St Jeor gives him a BMR of about 1,733 and a TDEE of about 2,079, which is 91 calories lower.

Example 3: Katch-McArdle with body fat

The same man measures 20% body fat.

1. Lean body mass = 81.65 × (1 − 0.20) ≈ 65.32 kg.
2. BMR = 370 + 21.6 × 65.32 ≈ 370 + 1,410.9 ≈ 1,781 calories.
3. TDEE = 1,780.9 × 1.2 ≈ 2,137 calories a day.

The three formulas give this one man TDEE values of 2,079, 2,137 and 2,170 calories. A spread like this is normal, and it is a good reminder that any TDEE is an estimate to test against real life.

From TDEE to a calorie target

The calculator gives targets as plain differences from your TDEE: maintain at your TDEE, mild loss at 250 calories below, loss at 500 below and gain at 250 above. For Example 1, that is 2,158, 1,908, 1,658 and 2,408 calories a day.

USDA’s Nutrition.gov calls 1 to 2 pounds a week a reasonable rate of weight loss. The CDC notes that people who lose weight at about that pace are more likely to keep it off. The calculator does not turn a calorie difference into pounds per week. Weight change is not a straight line, and your TDEE falls as your weight falls. For a plan that models these changes over time, the NIH’s Body Weight Planner uses a dynamic model of body weight change in adults.

These numbers are estimates for healthy adults, not medical or nutrition advice. Talk with a doctor or registered dietitian before making big changes, especially if you are pregnant, breastfeeding, under 18 or managing a health condition.

Common TDEE mistakes

• Picking the activity level for your best week. Choose the level that describes a normal week. One long run does not make a week “very active.”
• Mixing units. The equations expect kilograms and centimeters. Typing pounds into a kilogram formula more than doubles the weight term.
• Treating the result as exact. Two equations can differ by 100 calories or more for the same person, and the multipliers are rough conventions.
• Never recalculating. When your weight or routine changes, your BMR and TDEE change too.
• Using a guessed body fat number with Katch-McArdle. If you are not confident in the figure, Mifflin-St Jeor is the better choice.

Sources

All sources checked November 2026.

• Mifflin MD, St Jeor ST, et al. A new predictive equation for resting energy expenditure in healthy individuals. Am J Clin Nutr. 1990;51(2):241-247 (PubMed)
• Roza AM, Shizgal HM. The Harris Benedict equation reevaluated: resting energy requirements and the body cell mass. Am J Clin Nutr. 1984;40(1):168-182 (PubMed)
• Pavlidou E, et al. Revised Harris-Benedict Equation: New Human Resting Metabolic Rate Equation. Metabolites. 2023;13(2):189 (Table 1 lists the 1919, 1984 and 1990 equations)
• Tang M, et al. Metabolic adaptation fluctuates with different prediction equations. Front Nutr. 2025;12:1543263 (states the Katch-McArdle equation and cites McArdle, Katch and Katch, Exercise Physiology)
• USDA Nutrition.gov: What you need to know before getting started (rate of weight loss)
• CDC: Steps for Losing Weight
• NIDDK (NIH): About the Body Weight Planner

TDEE practice quiz: 10 questions

Test yourself with 10 multiple-choice questions. Choose an answer and press Submit to see if you are right and why. Your score appears at the end.

Frequently asked questions

What is the difference between TDEE and BMR?

BMR is the energy you burn at complete rest. TDEE is BMR plus everything you do in a day, including movement, exercise and digesting food. TDEE is always higher. With the conventional multipliers it runs from 1.2 to 1.9 times your BMR.

How accurate is a TDEE calculator?

It is a starting estimate. The 1984 Harris-Benedict study reported accuracy of about ±14% for resting needs in healthy people, and the activity multiplier adds more uncertainty on top. Compare the estimate with how your weight actually changes over a few weeks and adjust.

Which BMR formula is the most accurate?

No formula is right for everyone. Mifflin-St Jeor was built from 498 adults of normal weight and with obesity, and its authors found that the original Harris-Benedict equation ran about 5% high. That is why it is the default here. Katch-McArdle can suit you if you know your body fat percentage well.

Should I eat at my TDEE to lose weight?

Eating at your TDEE should keep your weight about the same. To lose weight, intake needs to be below TDEE. The calculator shows 250 and 500 calories below as plain reference points. For a personal plan, the NIH Body Weight Planner or a registered dietitian can help.

Does my TDEE change as I lose weight?

Yes. Weight is part of every BMR equation, so a lower weight means a lower BMR and TDEE. Recalculate after any noticeable change in your weight or activity.

Related calculators

• Unit converter for pounds, kilograms, inches and centimeters
• Percentage calculator
• Percent change calculator to track a change in weight or calories