TDEE & BMR Calculator
Enter your details below → select activity level → choose your goal → get calories + macros instantly
Key Metrics
Macronutrient Breakdown
All Calorie Goal Scenarios
What Is TDEE? The Complete Guide
Understanding Total Daily Energy Expenditure and why it is the most important number for your fitness goals
Total Daily Energy Expenditure (TDEE) is the total number of calories your body burns every single day. It is the most important number in nutrition science because it determines whether you lose fat, gain muscle, or maintain your current body composition. Simply put: eat below your TDEE to lose weight, eat above it to gain, eat at it to maintain.
TDEE is the sum of four components: Basal Metabolic Rate (BMR) — the calories burned at complete rest; Thermic Effect of Activity (TEA) — calories burned through deliberate exercise; Non-Exercise Activity Thermogenesis (NEAT) — calories burned through non-exercise movement like walking, fidgeting, and posture; and the Thermic Effect of Food (TEF) — the energy used to digest, absorb and metabolise food (approximately 10% of total intake).
BMR typically accounts for 60–75% of TDEE and is largely determined by lean body mass (muscle mass). This is why resistance training increases TDEE — more muscle tissue requires more energy to maintain, even at rest. Age causes BMR to decline by approximately 1–2% per decade after age 30, primarily due to loss of muscle mass (sarcopenia) — which can be counteracted by consistent strength training.
TEA (Exercise): 15–30% of TDEE
NEAT (Daily Movement): 6–10% of TDEE
TEF (Digestion): ~10% of food intake
BMR is highest, which is why sleep and rest still burn significant calories.
TDEE − 250 kcal: ~0.23 kg/week fat loss
TDEE ± 0 kcal: Weight maintenance
TDEE + 250 kcal: Lean muscle gain
TDEE + 500 kcal: Faster muscle gain
Age: BMR declines ~1–2%/decade after 30
Sex: Males typically have 5–10% higher BMR
Genetics: Accounts for ±200–400 kcal variation
Thyroid: Hypothyroidism can reduce BMR by 30–40%
The 3 BMR Formulas — Complete Scientific Reference
Mifflin-St Jeor, Harris-Benedict and Katch-McArdle formulas explained with history, accuracy and worked examples
All three BMR formulas are validated by peer-reviewed research and are widely used by registered dietitians, sports nutritionists and physicians. Each has different strengths depending on your situation. The formulas use weight (kg), height (cm) and age (years) as inputs, with Katch-McArdle additionally requiring lean body mass.
| Formula | BMR — Male | BMR — Female | Accuracy | Best Used For |
|---|---|---|---|---|
| 🔬 Mifflin-St Jeor (1990) | (10×W) + (6.25×H) − (5×A) + 5 | (10×W) + (6.25×H) − (5×A) − 161 | ±10% (best overall) | General population, most people |
| 📜 Harris-Benedict (Revised 1984) | (13.397×W) + (4.799×H) − (5.677×A) + 88.362 | (9.247×W) + (3.098×H) − (4.330×A) + 447.593 | ±10–15% | Historical baseline, widely recognised |
| 💪 Katch-McArdle | 370 + (21.6 × LBM) — same formula for both sexes | ±5% (if BF% accurate) | Lean athletes, known body fat % | |
Variables: W = weight in kg, H = height in cm, A = age in years, LBM = Lean Body Mass in kg (= body weight × (1 − body fat fraction)).
Activity Levels — Which Multiplier Should You Use?
Detailed descriptions of each activity factor with real-world examples to help you choose accurately
The activity multiplier is the most error-prone part of TDEE calculation. Research consistently shows people overestimate their activity level by one category. When uncertain, err on the lower side and adjust based on real-world weight changes.
| Level | Multiplier | Description | Examples | Weekly Exercise |
|---|---|---|---|---|
| 🪑 Sedentary | ×1.2 | Little or no exercise, desk job, mostly sitting | Office worker who drives to work and sits all day | 0 sessions |
| 🚶 Lightly Active | ×1.375 | Light exercise or sport 1–3 days per week | Office worker with 2–3 light gym sessions or walks | 1–3 sessions |
| 🏋️ Moderately Active | ×1.55 | Moderate exercise or sport 3–5 days per week | Regular gym-goer, recreational athlete, teacher on feet | 3–5 sessions |
| ⚡ Very Active | ×1.725 | Hard exercise 6–7 days per week | Competitive athlete, construction worker who also trains | 6–7 sessions |
| 🔥 Extra Active | ×1.9 | Very hard daily exercise + physical job, or twice-a-day training | Elite endurance athlete, military training, professional footballer | 2× daily |
Macronutrients — Protein, Carbs & Fat Explained
How to set optimal macro targets for fat loss, muscle gain and performance
Macronutrients (macros) are the three main nutrients that provide energy: protein (4 kcal/g), carbohydrates (4 kcal/g) and fat (9 kcal/g). While total calorie intake determines body weight change, the ratio of macros determines body composition changes — specifically, how much of any weight change comes from fat versus muscle tissue.
This calculator uses goal-specific macro splits backed by current sports nutrition research (ISSN — International Society of Sports Nutrition position stands), defaulting to higher protein targets to maximise muscle preservation during fat loss and muscle protein synthesis during surplus phases.
| Goal | Protein | Carbohydrates | Fat | Protein g/kg body weight |
|---|---|---|---|---|
| 🔥 Aggressive Fat Loss | 40% | 35% | 25% | ~2.2 g/kg (preserve muscle) |
| 📉 Moderate Fat Loss | 38% | 37% | 25% | ~2.0 g/kg |
| ⚖️ Mild Fat Loss | 35% | 40% | 25% | ~1.8 g/kg |
| 🎯 Maintenance | 30% | 45% | 25% | ~1.6 g/kg (RDA × 2) |
| 💪 Lean Muscle Gain | 30% | 50% | 20% | ~1.8 g/kg |
| 🏗️ Muscle Gain | 28% | 52% | 20% | ~2.0 g/kg |
TDEE, Metabolism & Fat Loss — Key Facts & Insights
Evidence-based facts every person tracking calories should know
The Brain Burns 20% of Your BMR
Despite weighing only ~1.4 kg, the human brain consumes roughly 20% of your total BMR — approximately 260–320 kcal/day. Mental tasks like studying or focused work increase brain glucose consumption slightly (5–10%), but not enough to significantly affect weight. This is why "thinking hard" does not lead to meaningful fat loss.
Sleep Deprivation Increases Appetite by 24%
Sleeping less than 7 hours per night increases levels of ghrelin (hunger hormone) by 24% and decreases leptin (fullness hormone) by 18%, according to University of Chicago research. Chronically sleep-deprived people consume an average of 300–500 more calories per day. Quality sleep of 7–9 hours is essential for body composition goals.
Muscle Burns 3× More Calories Than Fat at Rest
One kilogram of muscle tissue burns approximately 13 kcal/day at rest, while one kilogram of adipose (fat) tissue burns only ~4.5 kcal/day. Building 5 kg of muscle (achievable in 1–2 years for most beginners) increases BMR by ~40–65 kcal/day. While modest, this compounds over months and years, making resistance training critical for long-term metabolic health.
Metabolic Adaptation: Your Body Fights Back
When in a prolonged calorie deficit, the body adapts by reducing TDEE — a process called "metabolic adaptation" or "adaptive thermogenesis." Studies show that after 6+ months of dieting, TDEE can decrease by 100–500 kcal beyond what would be predicted from weight loss alone. Diet breaks (2-week maintenance phases) and refeed days partially counteract this adaptation.
Cold Exposure Increases Calorie Burn
Shivering can increase metabolic rate by 2–5× baseline. "Non-shivering thermogenesis" — activated by brown adipose tissue — burns additional calories during cold exposure even without shivering. Cold showers and cold plunge therapy have modest calorie-burning effects (20–100 kcal per session). The calorie burn is real but often overstated in popular media.
The Thermic Effect of Protein is 20–30%
The thermic effect of food (TEF) — the energy cost of digesting and processing nutrients — differs dramatically by macronutrient: protein 20–30%, carbohydrates 5–10%, fat 0–3%. This means eating 100 kcal of protein results in net 70–80 kcal; 100 kcal of fat gives net 97–100 kcal. High-protein diets have a measurable metabolic advantage of approximately 80–100 kcal/day.
The "Starvation Mode" Myth — Partially
Severely restricting calories (below ~800–1,000 kcal/day) does reduce TDEE through metabolic adaptation, but the body does not "stop burning fat" as popular myth suggests. The real dangers of very low calorie diets are: muscle mass loss (up to 50% of weight lost can be lean mass), micronutrient deficiencies, hormonal disruption, gallstone formation and severe hunger increasing binge risk.
Protein Timing: Post-Workout Matters Less Than Total Daily Intake
The anabolic window post-workout (the idea that you must consume protein within 30 minutes of training) is largely a myth. Research shows the total daily protein intake matters far more than timing. That said, consuming 20–40 g of protein within 2 hours of training does maximise muscle protein synthesis rates. Pre-workout protein is equally effective as post-workout protein.
How to Use the TDEE Calculator
Step-by-step guide to getting your most accurate TDEE estimate and acting on the results
- 1
Choose Your Measurement System
Select Metric (kg and cm) or Imperial (lb, feet and inches). All internal calculations use kg and cm — imperial inputs are automatically converted before any formula is applied. You can switch systems at any time without losing your inputs.
- 2
Enter Personal Details
Enter your biological sex (male or female), age in years, current body weight, and height. These four inputs are required for all three BMR formulas. If using Katch-McArdle, also enter your body fat percentage (obtainable from DEXA scan, BodPod, hydrostatic weighing, or skinfold callipers). Use your current weight, not your goal weight.
- 3
Select BMR Formula
For most people: choose Mifflin-St Jeor. If you know your accurate body fat percentage (from a professional measurement): choose Katch-McArdle for the most precise result. Harris-Benedict is useful for comparison — it typically gives a result 5–10% higher than Mifflin-St Jeor. Run all three to see the range and average them for extra accuracy.
- 4
Choose Your Activity Level Honestly
This is the most common point of error. Be honest with yourself — if you train 3× per week for an hour each session but have an office job and commute by car, you are Lightly Active (×1.375), not Moderately Active. Track your actual weight for 2–3 weeks after calculating TDEE; if you are gaining or losing faster than expected, adjust your activity level accordingly.
- 5
Set Your Goal and Review Results
Select your primary fitness goal. The calculator will display your BMR, TDEE, goal calories, all six calorie scenarios side by side, and a macronutrient breakdown in grams per day. Expand the Step-by-Step panel to see every formula and arithmetic step. Use the results as a starting point — recalculate every 4–6 weeks as your weight changes, as TDEE changes with body weight.
Frequently Asked Questions
Common questions about TDEE, BMR, calorie deficits, macros and weight management