What is TDEE and how is it calculated?

TDEE (Total Daily Energy Expenditure) is the total number of calories your body burns in a day, including basal metabolic rate (BMR), the thermic effect of food, and all physical activity. It is calculated by first estimating BMR using the Mifflin-St Jeor equation — the most validated formula for most adults — and then multiplying by an activity factor that accounts for your weekly exercise level. The result is the caloric intake needed to maintain your current weight.

How much protein do I need to build muscle?

Current evidence (Morton et al., 2018; ISSN Position Stand 2017) supports 1.6–2.2 g of protein per kg of bodyweight per day for maximising muscle protein synthesis in resistance-trained individuals. The lower end (1.6 g/kg) is sufficient for most intermediate lifters in a caloric surplus; the upper end (2.2 g/kg) is advisable during a caloric deficit to minimise muscle loss. This calculator defaults to 2.0 g/kg for muscle gain and 2.2 g/kg for fat loss.

What caloric surplus is needed for muscle gain?

A modest surplus of 200–500 kcal above TDEE is sufficient to support muscle growth while minimising fat gain. Larger surpluses do not produce proportionally more muscle — they primarily increase fat accumulation. Natural lifters can gain roughly 0.5–1 kg of lean mass per month under optimal conditions; a 200–500 kcal surplus provides the energy margin required without excessive fat gain.

How large a caloric deficit is safe for fat loss?

A deficit of 300–500 kcal/day below TDEE produces ~0.3–0.5 kg of fat loss per week — a rate that preserves most muscle mass and strength. Deficits above 700 kcal/day accelerate muscle loss, reduce training performance, and increase hormonal disruption. During a cut, maintaining high protein (2.2 g/kg+) and continuing resistance training are the most important variables for minimising lean mass loss.

Tool · Updated 30 May 2026

TDEE & Macronutrient Calculator

Enter your age, weight, height, sex, and activity level to get your Total Daily Energy Expenditure. Then select your goal — muscle gain, fat loss, or maintenance — and receive personalised protein, carb, and fat targets.

Calories and macronutrients set the ceiling for what your training can achieve. You cannot build muscle in a sustained deficit, and you cannot lose fat without one. This free calculator uses the Mifflin-St Jeor equation for BMR — the most validated formula for adults — multiplied by an activity factor to estimate TDEE, then distributes calories into evidence-based macronutrient targets. No account required.

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Your details

Unit:

Biological sex (affects BMR formula)

Age (years)

Body weight (kg)

Height (cm)

Activity level

Goal

Fill in your details above to calculate your TDEE and macros.

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Understanding TDEE and why it matters for training

Total Daily Energy Expenditure is the total number of calories your body uses over 24 hours. It is the single most important number for nutrition planning because it determines whether your body is in an energy surplus (gains mass), deficit (loses mass), or equilibrium (maintains mass). Every nutrition goal — muscle gain, fat loss, or body recomposition — starts with an accurate TDEE estimate.

The four components of TDEE

TDEE comprises: (1) Basal Metabolic Rate (BMR) — the energy your body uses at complete rest, typically 60–70% of TDEE; (2) Thermic Effect of Food (TEF) — the energy cost of digesting and absorbing food, roughly 10% of total calories; (3) Non-Exercise Activity Thermogenesis (NEAT) — all movement that isn't structured exercise (fidgeting, walking, standing); (4) Exercise Activity Thermogenesis (EAT) — your gym sessions and sport. The activity factor in this calculator approximates the combined contribution of NEAT and EAT.

The Mifflin-St Jeor equation

This calculator uses the Mifflin-St Jeor equation, published in 1990, which has been validated as the most accurate BMR formula for most adult populations (Frankenfield et al., 2005). For males: BMR = (10 × weight in kg) + (6.25 × height in cm) − (5 × age) + 5. For females: same formula minus 161 instead of +5. The result is multiplied by an activity factor ranging from 1.2 (sedentary) to 1.9 (extremely active) to produce TDEE.

Why TDEE estimates vary — and how to calibrate

Formulas estimate TDEE with approximately ±10–15% accuracy. Factors that cause individuals to deviate: body composition (muscle burns more than fat at rest), metabolic adaptation (chronic dieting reduces TDEE), gut microbiome differences, and hormonal status. The most accurate method to find your true TDEE: track calories and body weight daily for 2–3 weeks at a stable eating pattern. If weight is stable, that calorie intake is your TDEE.

Protein: the non-negotiable macro

Protein is the only macronutrient that directly provides amino acids for muscle protein synthesis. It also has the highest thermic effect (25–30% of calories consumed are spent digesting it), making high-protein diets metabolically advantageous during a cut. The ISSN (2017) Position Stand recommends 1.4–2.0 g/kg for active individuals seeking body composition improvements, with higher intakes (up to 3.1 g/kg) showing no adverse effects in healthy adults.

Activity level multipliers explained

Level	Multiplier	Who it fits	Weekly training
Sedentary	× 1.2	Desk job, no structured exercise	0 days
Lightly active	× 1.375	Light exercise, standing job	1–3 days
Moderately active	× 1.55	Regular gym sessions, active lifestyle	3–5 days
Very active	× 1.725	Hard training, sport athlete	6–7 days
Extremely active	× 1.9	Physical job + twice-daily training	Daily + job

Most recreational gym-goers 3–5 days/week fit the "moderately active" category. When in doubt, choose the lower multiplier and adjust based on weekly weight trend data.

Macronutrient targets by goal

Muscle gain (lean bulk)

Target calories: TDEE + 200–500 kcal. Protein: 1.8–2.2 g/kg. Fat: 25–30% of total calories. Carbohydrates: remainder. The caloric surplus fuels muscle protein synthesis and provides glycogen for training intensity. Larger surpluses (700+ kcal) do not produce proportionally more muscle — they primarily increase fat deposition. Aim for 0.3–0.5% bodyweight gain per week as a target rate.

Maintenance (body recomposition)

Target calories: at TDEE. Protein: 2.0–2.4 g/kg. Fat: 25% of calories. Carbohydrates: remainder. At maintenance, body recomposition (simultaneous fat loss and muscle gain) is possible for beginners and those returning from detraining. Experienced lifters see minimal recomposition at maintenance — a deliberate bulk or cut phase is more efficient for well-trained individuals.

Fat loss (moderate cut)

Target calories: TDEE − 300–500 kcal. Protein: 2.2–2.8 g/kg. Fat: 20–25% of calories. Carbohydrates: remainder. High protein on a cut is critical to preserve muscle mass. The deficit rate of ~0.3–0.5 kg/week is slow enough to maintain training performance. Rapid weight loss (1+ kg/week) correlates strongly with muscle loss and hormonal disruption.

How to use this TDEE calculator

Step 1 — Enter your biometric data

Select your biological sex, then enter age, current bodyweight, and height. The calculator uses metric (kg / cm) by default — toggle to lbs / inches if preferred. Use your current weight, not your target weight. The TDEE calculation describes your current energy needs, not a hypothetical future state.

Step 2 — Select activity level honestly

Most people overestimate their activity level. "Moderately active" means consistent gym training 3–5 days per week with a relatively sedentary job. If you train 4 days a week but sit at a desk for 9 hours, "lightly active" may be more accurate — desk workers' NEAT is significantly lower than their perceived activity level. When in doubt, choose the lower multiplier and verify against real-world weight data.

Step 3 — Choose your goal and read the targets

Select muscle gain, maintenance, or fat loss from the dropdown. Your target calories and macro breakdown appear immediately. Use these as starting points for the next 2–3 weeks. If your weight trend doesn't match your goal (e.g. not losing weight on a cut), adjust by 100–200 kcal and reassess after another week.

Step 4 — Track training to maximise the nutrition investment

Nutrition and training are interdependent. Eating at a surplus without progressive resistance training produces primarily fat gain, not muscle. Eating at a deficit without training loses both fat and muscle. The Personal Trainer app helps you maintain training progression alongside your nutrition plan — logging sets, tracking volume, and ensuring your muscle is receiving the progressive stimulus needed to utilise the protein in your diet.

FAQ

How accurate is the TDEE estimate?

The Mifflin-St Jeor formula is accurate to within ±10–15% for most adults. For better accuracy, track your actual calorie intake and body weight daily for 2–3 weeks at a stable eating pattern — if weight is stable, your intake equals your TDEE. The formula is a starting point; real-world data is more reliable than any equation.

How much protein do I actually need to build muscle?

Current consensus (ISSN, 2017; Morton et al., 2018) supports 1.6–2.2 g/kg/day for maximising muscle protein synthesis in resistance-trained individuals. Intakes above 2.2 g/kg show diminishing returns in studies of natural lifters. Higher intakes (up to 3.1 g/kg) are safe and may help preserve muscle during aggressive cuts. This calculator targets 2.0 g/kg for muscle gain and 2.2 g/kg for fat loss.

Is my data saved?

Yes. Your inputs (age, weight, height, sex, activity level, goal) are stored in your browser's localStorage. They persist across page reloads and browser restarts. Nothing is sent to a server. Click Reset to clear all stored values.

Should I recalculate TDEE as I lose or gain weight?

Yes. TDEE decreases as you lose weight (less mass to maintain) and increases as you gain muscle. For ongoing fat loss, recalculate every 2–4 weeks and adjust calorie targets accordingly. A common mistake is maintaining the same calorie intake as weight drops — what was a 400 kcal deficit at 90 kg may become a 100 kcal deficit at 80 kg because TDEE has decreased.

What if I want to do a body recomposition?

Body recomposition (building muscle while losing fat simultaneously) is most effective for beginners, those returning after a long break, or overweight individuals. At maintenance calories with high protein and progressive resistance training, recomposition occurs naturally in these populations. For intermediate and advanced lifters, a dedicated lean bulk or cut cycle produces faster, more measurable results than attempting recomposition at maintenance.

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