How to Calculate Your TDEE (Total Daily Energy Expenditure)

If you've ever tried to lose fat, build muscle, or simply maintain your weight, you've run into one number that controls all of it: your TDEE, short for Total Daily Energy Expenditure. It's the total number of calories your body burns in a typical 24-hour day, and it's the single most useful figure in nutrition. Eat below it and you lose weight; eat above it and you gain. Everything else, from macros to meal timing, is a detail layered on top of this one foundation.

The good news is that calculating your TDEE is straightforward arithmetic. You start with your BMR (the calories you'd burn lying in bed all day), multiply by an activity factor, and you're done. This guide walks through every step with the exact formula scientists use, plus two fully worked examples, one man and one woman, so you can follow the math and then apply the 500-calorie rule to hit your goal.

This article is for general informational and educational purposes only and is not medical or nutritional advice. Calorie formulas are estimates; consult a doctor or registered dietitian before starting a weight-loss or muscle-gain program, especially if you have a health condition.

What TDEE Actually Measures

Your TDEE is the sum of four components your body spends energy on every day:

• Basal Metabolic Rate (BMR) - the energy needed just to keep you alive: breathing, circulating blood, regulating temperature, and running your organs. For most people this is 60 to 70% of total daily burn.
• Thermic Effect of Food (TEF) - the calories burned digesting and processing what you eat, roughly 10% of intake. Protein has the highest thermic effect.
• Exercise Activity Thermogenesis (EAT) - calories burned during deliberate workouts like lifting, running, or cycling.
• Non-Exercise Activity Thermogenesis (NEAT) - everything else you do while awake: walking, typing, fidgeting, standing, doing chores. NEAT varies wildly between people and can swing your daily burn by hundreds of calories.

You don't have to estimate each piece separately. The standard approach is to calculate your BMR with a validated equation and then multiply by an activity factor that bundles TEF, EAT, and NEAT into one number. That product is your TDEE.

Step 1: Calculate Your BMR With the Mifflin-St Jeor Equation

The most accurate widely used formula for estimating BMR is the Mifflin-St Jeor equation, published in 1990 and recommended by the Academy of Nutrition and Dietetics as the most reliable predictive equation for healthy adults. It uses your weight in kilograms, height in centimeters, and age in years:

• Men: BMR = (10 × weight in kg) + (6.25 × height in cm) − (5 × age) + 5
• Women: BMR = (10 × weight in kg) + (6.25 × height in cm) − (5 × age) − 161

The only difference between the male and female versions is the final constant (+5 for men, −161 for women), which accounts for average differences in lean body mass. If you think in US units, convert first: divide pounds by 2.205 to get kilograms, and multiply inches by 2.54 to get centimeters. Our BMR calculator does this conversion automatically if you'd rather not do it by hand.

Step 2: Multiply by Your Activity Multiplier to Get TDEE

Once you have your BMR, you multiply it by an activity multiplier that reflects how much you move during a typical week. These are the standard factors used across the fitness and dietetics world:

TDEE = BMR × activity multiplier. That's the whole formula. Most people overestimate their activity level, so when in doubt, pick the lower bracket. If you sit at a desk all day and hit the gym three times a week, you're probably lightly to moderately active, not very active. You can always adjust after a few weeks of tracking real results.

Worked Example 1: A 35-Year-Old Man

Let's run the numbers for Marcus: a 35-year-old man who weighs 185 lb (83.9 kg), stands 5'11" (180.3 cm), and works a desk job but lifts weights four times a week.

First, his BMR using the men's equation:

• 10 × 83.9 = 839
• 6.25 × 180.3 = 1,126.9
• 5 × 35 = 175
• BMR = 839 + 1,126.9 − 175 + 5 = 1,795.9 ≈ 1,796 calories/day

Next, his activity level. Four moderate-to-hard gym sessions a week plus a desk job lands him at moderately active (1.55):

• TDEE = 1,796 × 1.55 = 2,784 calories/day

So Marcus burns roughly 2,784 calories on a typical day. To maintain his current weight, that's how much he eats. To lose fat or build muscle, he adjusts from there, which we'll cover below.

Worked Example 2: A 30-Year-Old Woman

Now meet Priya: a 30-year-old woman who weighs 150 lb (68.0 kg), stands 5'5" (165.1 cm), and does light cardio and yoga two days a week.

Her BMR using the women's equation:

• 10 × 68.0 = 680
• 6.25 × 165.1 = 1,031.9
• 5 × 30 = 150
• BMR = 680 + 1,031.9 − 150 − 161 = 1,400.9 ≈ 1,401 calories/day

Two light workout days a week puts Priya at lightly active (1.375):

• TDEE = 1,401 × 1.375 = 1,926 calories/day

Priya burns about 1,926 calories on a typical day. Notice how her TDEE is meaningfully lower than Marcus's, mostly because she's lighter, shorter, and carries less lean mass on average, all of which the equation accounts for. This is exactly why generic "eat 2,000 calories" advice fails so many people: your maintenance number is personal.

Step 3: Use the 500-Calorie Rule to Cut or Bulk

Your TDEE is your maintenance number. To change your weight, you create a deliberate gap between what you eat and what you burn. The classic guideline is the 500-calorie rule, based on the long-standing estimate that roughly 3,500 calories equals about one pound of body fat. A daily deficit or surplus of 500 calories therefore works out to about one pound per week.

To lose fat (cut):

• Subtract 500 from your TDEE for about 1 lb of fat loss per week.
• Marcus: 2,784 − 500 = 2,284 calories/day to lose roughly a pound a week.
• Priya: 1,926 − 500 = 1,426 calories/day for the same rate.

To build muscle (bulk):

• Add 250 to 500 above your TDEE for a controlled lean surplus. A smaller surplus (around 250-300) minimizes fat gain while still fueling muscle growth.
• Marcus: 2,784 + 300 = ~3,084 calories/day to build muscle with minimal fat gain.
• Priya: 1,926 + 250 = ~2,176 calories/day for a lean bulk.

A few important guardrails. Don't cut more than about 20-25% below your TDEE; aggressive deficits cost you muscle, tank your energy, and rarely last. The CDC recommends a sustainable pace of 1 to 2 pounds per week for weight loss. And don't let your intake fall below roughly 1,500 calories/day for men or 1,200 for women without medical supervision, very-low-calorie diets need oversight. You can model any deficit or surplus with our calorie deficit calculator to see your projected weekly rate before you commit.

Turning Your Calorie Target Into Macros

Your TDEE tells you how much to eat; macronutrients tell you what those calories should be made of. Three macros supply energy, and each has a fixed calorie value: protein and carbohydrates contain about 4 calories per gram, while fat contains about 9 calories per gram. Once you know your daily calorie target, you can split it into a protein, fat, and carbohydrate plan.

Protein is the macro to anchor on, especially when you're cutting, because it preserves muscle in a deficit and keeps you full. A practical, evidence-based target for active adults is roughly 0.7 to 1 gram of protein per pound of body weight. For Marcus at 185 lb, that's about 130 to 185 grams of protein a day; for Priya at 150 lb, about 105 to 150 grams. The Institute of Medicine sets the bare minimum (RDA) far lower at 0.36 grams per pound, but that floor is designed to prevent deficiency, not to build or retain muscle.

A simple starting framework once protein is set: fill roughly 20 to 35% of calories from fat (the USDA Dietary Guidelines' acceptable range) and let carbohydrates make up the rest, since carbs fuel hard training. For example, Marcus cutting at 2,284 calories might aim for ~180 g protein (720 cal), ~63 g fat (570 cal), and ~250 g carbs (1,000 cal). These are starting points, not rigid rules, but pairing your calorie number with a sensible protein floor is what turns a TDEE estimate into a results-driving plan.

Why Your Real Results May Differ

The 3,500-calories-per-pound rule and the activity multipliers are useful starting points, not laws of physics. Real-world weight change is messier for several reasons:

• Water weight can swing the scale several pounds in a day, independent of fat. Judge progress by weekly averages, not daily readings.
• Adaptive thermogenesis: as you lose weight, your body burns slightly fewer calories, so a deficit that worked at 200 lb may stall at 180 lb. Recalculate your TDEE every 10-15 pounds.
• NEAT downshift: when you eat less, you may unconsciously move less, fewer fidgets and steps, shrinking your real burn.
• Tracking error: most people underestimate how much they eat by 20% or more. A food scale beats eyeballing portions.

The smart approach is to treat your calculated TDEE as a hypothesis. Eat at that level for two to three weeks, track your weight trend honestly, and adjust by 100-200 calories based on what the scale actually does. The math gets you in the right zip code; your own data dials in the address.

The Bottom Line

Calculating your TDEE is a three-step process: find your BMR with the Mifflin-St Jeor equation, multiply by an honest activity factor to get your maintenance calories, then apply the 500-calorie rule to cut or bulk toward your goal. Marcus lands around 2,784 maintenance calories; Priya around 1,926, proof that your number is uniquely yours and worth calculating rather than guessing.

Skip the longhand arithmetic and let our TDEE calculator do all three steps in seconds, then revisit it every few weeks as your weight and training change. A two-minute calculation today is the difference between aimless dieting and a plan that actually moves the scale.