IRONCOMPARE

TDEE CALCULATOR

Calculate your Total Daily Energy Expenditure using the Mifflin-St Jeor formula. Get your maintenance calories, BMR, calorie targets for cutting or bulking, and a macro breakdown instantly.

CALCULATE YOUR TDEE

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WHAT IS TDEE?

TDEE — Total Daily Energy Expenditure — is the total number of calories your body burns in a single day. It accounts for everything: your resting metabolism, physical activity, workouts, and even the energy cost of digesting food. TDEE is your maintenance calorie level — the number that keeps your weight stable.

Understanding your TDEE is the foundation of any nutrition plan, whether your goal is fat loss, muscle gain, or body recomposition. Eat below your TDEE and you lose weight. Eat above it and you gain. Eat at it and you maintain. No nutrition approach works without accounting for this number.

THE MIFFLIN-ST JEOR FORMULA

This calculator uses the Mifflin-St Jeor equation, published in 1990 and widely validated as the most accurate BMR formula for the general population. It outperforms the older Harris-Benedict equation in most studies.

Male BMR: (10 × weight in kg) + (6.25 × height in cm) − (5 × age) + 5

Female BMR: (10 × weight in kg) + (6.25 × height in cm) − (5 × age) − 161

TDEE is then calculated by multiplying BMR by an activity factor ranging from 1.2 (sedentary) to 1.9 (extra active). This multiplication accounts for all movement beyond rest — from walking to the kitchen to intense training sessions.

ACTIVITY LEVELS EXPLAINED

The activity multiplier is the most impactful and most commonly misjudged input in TDEE calculations. Most people overestimate their activity level.

  • Sedentary (×1.2): Office or desk work with minimal movement. No structured exercise or very occasional light walking.
  • Lightly Active (×1.375): Light exercise 1–3 days per week. Casual gym sessions, walking, or recreational activity.
  • Moderately Active (×1.55): Consistent exercise 3–5 days per week at moderate intensity. Most regular gym-goers fall here.
  • Very Active (×1.725): Hard training 6–7 days per week. Competitive athletes in-season or those doing two-a-day sessions.
  • Extra Active (×1.9): Extremely demanding physical job (construction, military) combined with daily intense training. Rare outside professional athletics.

USING TDEE FOR WEIGHT LOSS

Fat loss requires a sustained calorie deficit — consuming fewer calories than your TDEE. One pound of body fat contains approximately 3,500 calories, so a 500-calorie daily deficit produces roughly 1 lb of fat loss per week. A 250-calorie deficit produces about 0.5 lbs per week.

Moderate deficits (250–500 calories) are generally preferable to aggressive ones because they preserve more muscle mass, maintain training performance, and are easier to sustain. Avoid cutting below your BMR — your body needs those calories to sustain basic physiological functions. When dieting, prioritize high protein intake (0.7–1g per lb of bodyweight) to protect muscle tissue.

USING TDEE FOR MUSCLE GAIN

Building muscle requires a calorie surplus above your TDEE. Without enough calories, your body cannot synthesize new muscle tissue at its maximum rate regardless of how hard you train. A moderate surplus of 250–500 calories per day provides enough energy for muscle growth while minimizing fat gain.

Natural lifters gain muscle slowly — roughly 1–2 lbs per month is realistic. Because of this, a moderate surplus is almost always the smarter choice over a large one. A larger surplus does not meaningfully increase the rate of muscle gain; it primarily increases fat accumulation. A lean bulk (moderate surplus) maximizes the muscle-to-fat ratio of weight gained.

UNDERSTANDING MACRONUTRIENTS

Once you know your calorie target, the next step is distributing those calories across the three macronutrients: protein, carbohydrates, and fat. Each plays a distinct role in body composition and performance.

  • Protein (4 kcal/g): The building block of muscle. Prioritize 0.7–1g per pound of bodyweight daily. Higher protein intake also increases satiety, making it easier to maintain a deficit.
  • Carbohydrates (4 kcal/g): The primary fuel for high-intensity training. Higher carb intake supports better performance in the gym and faster recovery. Particularly important for those training 4+ days per week.
  • Fat (9 kcal/g): Essential for hormone production, joint health, and fat-soluble vitamin absorption. Avoid dropping fat below 15–20% of total calories, especially for men, as it can suppress testosterone production.

FREQUENTLY ASKED QUESTIONS

What is TDEE?
TDEE stands for Total Daily Energy Expenditure — the total number of calories your body burns in a day. It combines your Basal Metabolic Rate (the calories burned at complete rest) with calories burned through physical activity and the thermic effect of food. TDEE is your maintenance calorie level: eating at TDEE keeps your weight stable, eating below it causes fat loss, and eating above it causes weight gain.
What is BMR and how does it differ from TDEE?
BMR (Basal Metabolic Rate) is the number of calories your body needs to sustain basic functions — breathing, circulation, organ function, and cell repair — at complete rest. It represents your absolute minimum calorie need. TDEE multiplies your BMR by an activity factor to account for the calories burned through movement, exercise, and daily activities. For most people, TDEE is 20–90% higher than BMR depending on their activity level.
What formula does this calculator use?
This calculator uses the Mifflin-St Jeor equation, developed in 1990 and widely considered the most accurate BMR formula for the general population. The formula is: BMR (male) = (10 × weight in kg) + (6.25 × height in cm) − (5 × age) + 5, and BMR (female) = (10 × weight in kg) + (6.25 × height in cm) − (5 × age) − 161. TDEE is then calculated by multiplying BMR by your activity multiplier.
How do I choose the right activity level?
Activity levels are the most common source of TDEE calculation errors — most people overestimate how active they are. Sedentary (×1.2) means a desk job with little or no structured exercise. Lightly Active (×1.375) means light exercise 1–3 days per week. Moderately Active (×1.55) means consistent exercise 3–5 days per week at moderate intensity. Very Active (×1.725) means hard training 6–7 days per week. Extra Active (×1.9) is reserved for people with physically demanding jobs combined with daily exercise. When in doubt, choose one level lower than you think — it is easier to add calories than to cut them.
How many calories should I eat to lose weight?
A calorie deficit of 500 calories per day below TDEE produces approximately 1 pound (0.45 kg) of fat loss per week — a pace considered aggressive but sustainable. A 250-calorie deficit produces roughly 0.5 lbs per week, which is gentler and easier to maintain. Both approaches work; the right pace depends on how much weight you want to lose and how quickly. Avoid deficits larger than 1,000 calories per day without medical supervision, as large deficits can cause muscle loss and metabolic adaptation.
How many calories should I eat to build muscle?
Building muscle requires a calorie surplus. A moderate bulk of 250 calories above TDEE adds roughly 0.5 lbs per week — most of which will be muscle if you are resistance training consistently. An aggressive bulk of 500 calories above TDEE adds about 1 lb per week but accumulates more body fat. For most natural lifters, a lean bulk (moderate surplus) is the most efficient approach: slower weight gain means a higher ratio of muscle to fat gained.
What is the 40/30/30 macro split?
The 40/30/30 split — 40% of calories from carbohydrates, 30% from protein, and 30% from fat — is a popular balanced macronutrient distribution. It provides sufficient protein to support muscle building and recovery, enough carbohydrates to fuel training, and enough fat to support hormone production and satiety. It is a solid starting point for most people. Athletes with high training volumes may benefit from more carbohydrates, while those following lower-carb diets may shift more calories toward protein and fat.
How accurate is this TDEE calculator?
The Mifflin-St Jeor equation is the most validated BMR formula for the general population, with an average error of ±10% in research studies. Activity multipliers introduce additional variability because self-reported activity levels are inherently subjective. Use your calculated TDEE as a starting point, then adjust based on real-world results over 2–3 weeks. If you are gaining weight at maintenance, reduce intake by 100–200 calories. If you are losing weight at maintenance, increase intake. The calculator gives you the best possible estimate — your body will tell you the rest.
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