How to Calculate TDEE: Your Maintenance Calories, Step by Step

Your TDEE is the single most useful number for planning weight loss, weight gain, or maintenance. It tells you how many calories your body actually uses in a normal day, once you account for both your resting metabolism and your movement. Below you will find the exact formula, the activity multipliers, a fully worked example, and the mistakes that throw people off. You can also skip the arithmetic and use our TDEE calculator to get your number instantly.

What is TDEE?

TDEE, or Total Daily Energy Expenditure, is the total number of calories your body burns in 24 hours. It is the sum of your resting metabolism plus every calorie you spend digesting food, walking, exercising, and fidgeting. In plain terms, your TDEE is your maintenance calories: eat at that number and your weight stays roughly stable over time.

TDEE is built on top of your BMR (Basal Metabolic Rate), the calories you would burn lying in bed all day doing nothing. Because almost nobody lies in bed all day, we multiply BMR by an activity factor to reach the real-world total. That is the whole idea behind the formula.

What is the formula to calculate TDEE?

The formula is TDEE = BMR x activity factor. To get BMR, most modern calculators use the Mifflin-St Jeor equation, published in 1990, because it tends to be more accurate for today's population than older formulas. The equation is sex-specific:

• Men: BMR = (10 x weight in kg) + (6.25 x height in cm) - (5 x age in years) + 5
• Women: BMR = (10 x weight in kg) + (6.25 x height in cm) - (5 x age in years) - 161

The Mifflin-St Jeor equation was validated in the American Journal of Clinical Nutrition (Mifflin et al., 1990), and clinics such as the Cleveland Clinic describe BMR and activity level as the two pieces that combine into total daily calorie needs. Once you have BMR, you multiply it by the factor that matches your typical week.

Which activity factor should I use?

Pick the activity factor that matches your honest weekly average, not your best week. Overestimating activity is the most common reason a TDEE estimate comes out too high. Here are the standard multipliers.

Most office workers who train a few times a week land between lightly active (1.375) and moderately active (1.55). When in doubt, choose the lower factor and adjust after a couple of weeks of real-world results.

How do I calculate my TDEE, step by step?

Here is a full worked example for a 30-year-old man who weighs 80 kg, stands 180 cm tall, and trains moderately (factor 1.55).

1. Convert your units. Weight 80 kg, height 180 cm, age 30. If you use pounds and inches, divide pounds by 2.205 for kg and multiply inches by 2.54 for cm.
2. Calculate the weight term. 10 x 80 = 800.
3. Add the height term. 6.25 x 180 = 1125. Running total: 800 + 1125 = 1925.
4. Subtract the age term. 5 x 30 = 150. Running total: 1925 - 150 = 1775.
5. Apply the sex constant. For men, add 5: 1775 + 5 = 1780. That is the BMR, about 1780 calories.
6. Multiply by your activity factor. 1780 x 1.55 = 2759. That is the TDEE, roughly 2760 calories per day.

So this person burns about 2,760 calories on a normal day. To lose weight they would eat below that; to gain weight they would eat above it. A common starting point is a deficit or surplus of 300 to 500 calories per day, which many clinics link to roughly 0.3 to 0.5 kg of weight change per week.

How do I use TDEE to lose or gain weight?

Your TDEE is the pivot point. Eating below it creates a calorie deficit and drives weight loss; eating above it creates a surplus and supports weight or muscle gain. It is not a fixed target for life, because your TDEE drops as you lose weight and shifts with activity, so you recalculate every few weeks.

• To lose fat: subtract 300 to 500 calories from your TDEE for a gradual, sustainable loss.
• To maintain: eat at your TDEE and track your weight trend over two to three weeks.
• To gain muscle: add 250 to 500 calories above your TDEE and pair it with resistance training.
• Recalculate: every 4 to 6 weeks, or after roughly 4 to 5 kg of weight change, because your numbers move.

Once you know your maintenance number, tools like a calorie calculator or a macro calculator help you split those calories into daily targets and protein, carb, and fat portions.

Common mistakes when calculating TDEE

Most TDEE errors come from bad inputs, not bad math. Avoid these and your estimate will be far more reliable.

• Overrating your activity level. A few gym sessions do not make you very active. When unsure, drop one tier.
• Mixing units. The Mifflin-St Jeor formula expects kilograms and centimeters. Convert before you calculate.
• Treating the number as exact. TDEE is a statistical estimate. Real needs vary with genetics, sleep, hormones, and non-exercise movement.
• Never adjusting. If the scale does not move after two to three weeks, revise your intake based on your own results, not the formula.
• Counting exercise twice. If your activity factor already includes training, do not also add back calories from your fitness tracker.

TDEE is one of several body metrics worth understanding together. If you are building a full picture of your health, it pairs naturally with BMI, explained in plain language and with what a good waist-to-hip ratio is.

Final takeaway

Calculating TDEE is genuinely simple once you have the two pieces: find your BMR with the Mifflin-St Jeor equation, then multiply by the activity factor that matches your real week. The result is your maintenance calories, the anchor for any weight goal. Run the numbers by hand to understand them, then let the calculator do the arithmetic and revisit your estimate as your body and routine change.