Macros & TDEE Calculator
Free TDEE & Macros Calculator - Daily Calorie and Macro Needs
TDEE (Daily Calories)
2564
Basal Metabolic Rate (BMR)
1865 cal/day
Macro Breakdown (Keto)
Daily Targets
How This Calculator Works
Purpose
Calculate your Total Daily Energy Expenditure (TDEE) using the Harris-Benedict equation — the most widely validated BMR formula in nutritional science. This calculator provides personalized calorie targets for cutting (fat loss), maintenance, and bulking (muscle gain), along with your optimal macronutrient breakdown (protein, fat, and carbohydrates) based on your weight and goals. All calculations adjust for your specific activity level using PAL (Physical Activity Level) multipliers.
The Problem It Solves
Generic diet advice — "eat 2,000 calories a day" or "reduce portion sizes" — ignores the fact that calorie needs vary enormously between individuals. A 6'2" male powerlifter and a 5'2" sedentary female have wildly different energy requirements. Following the wrong target means either under-eating (muscle loss, fatigue, metabolic adaptation) or over-eating (unintended weight gain). This calculator derives your specific TDEE from your actual body stats and lifestyle, giving you a defensible, science-backed number to build your nutrition plan around.
How to Use It
Step 1: Enter your age, gender, weight (lbs), and height (feet/inches). Step 2: Select your honest activity level — most people overestimate this; "lightly active" (1-3 days/week gym) is correct for most. Step 3: Review your TDEE (maintenance calories), BMR (at-rest calories), and the macro breakdown. Use the deficit number (−500 cal) to lose ~1 lb/week, or the surplus number (+500 cal) to build muscle. Adjust based on 2-3 weeks of real-world results.
The Formula
Input Fields
- • Age
- • Gender
- • Weight (lbs)
- • Height (ft/in)
- • Activity level
Output Data
- • TDEE (calories/day)
- • BMR (calories/day)
- • Protein / Fat / Carb grams
- • Deficit & surplus targets
Frequently Asked Questions
What is TDEE and how is it different from BMR?+
BMR (Basal Metabolic Rate) is the minimum number of calories your body burns at complete rest just to sustain vital functions — breathing, circulation, cell repair, and temperature regulation. It's what you'd burn lying in bed all day. TDEE (Total Daily Energy Expenditure) is your BMR multiplied by an activity factor that accounts for movement, exercise, and the thermic effect of food. For most adults, TDEE is 40-100% higher than BMR. A sedentary person with a BMR of 1,600 might have a TDEE around 1,920; a highly active athlete might have a TDEE of 2,800+. Eat at your TDEE to maintain weight.
How many calories should I eat to lose weight?+
To lose approximately 1 pound per week, create a daily deficit of 500 calories below your TDEE (shown as the "Deficit" number in this calculator). This is based on the widely cited equivalence of ~3,500 calories per pound of body fat. For example, if your TDEE is 2,500 calories, eating 2,000 calories daily creates a 3,500 calorie weekly deficit. For faster loss (2 lbs/week), target a 1,000 calorie deficit — but this is the practical maximum before muscle loss accelerates. Never sustain intake below your BMR. High protein intake (0.7-1g per lb of body weight) is critical during a cut to preserve lean muscle mass.
What are macros and why do they matter?+
Macronutrients are the three caloric building blocks of food: protein (4 cal/g), carbohydrates (4 cal/g), and fat (9 cal/g). Getting the right macro ratio for your goals matters as much as total calories. For general fat loss while preserving muscle: 35-40% protein, 25-30% fat, 30-35% carbs. For ketogenic diets: 70-75% fat, 20-25% protein, 5% carbs. For muscle building: 25-30% protein, 50-55% carbs, 20% fat. For endurance athletes: 55-65% carbs. This calculator shows a balanced starting-point macro split based on your body weight — adjust based on performance and body composition feedback over 4-6 weeks.
How accurate is the Harris-Benedict formula?+
The Harris-Benedict equation (revised by Roza and Shizgal in 1984) is accurate within 5-10% for most non-athlete adults, which is sufficient for dietary planning purposes. This calculator uses the Harris-Benedict formula because it remains the most clinically validated and widely cited BMR equation. For athletic populations with high muscle mass, the Katch-McArdle formula (which uses lean body mass) is more accurate but requires body fat percentage data. The best approach: use this calculator as a starting point, then track actual weight changes over 2-3 weeks and adjust your intake by 100-200 calories in either direction based on real results.
Deep Dive: The Science of Total Daily Energy Expenditure
Total Daily Energy Expenditure (TDEE) is the sum of four components: Basal Metabolic Rate (BMR), the Thermic Effect of Food (TEF), Exercise Activity Thermogenesis (EAT), and Non-Exercise Activity Thermogenesis (NEAT). BMR — the energy needed to sustain basic life functions at rest — accounts for 60-70% of TDEE. The Mifflin-St Jeor equation, published in 1990, is currently the most validated BMR estimate for non-athletes: for men, BMR = (10 × weight_kg) + (6.25 × height_cm) - (5 × age) + 5; for women, subtract 161 instead of adding 5. The older Harris-Benedict equation (1919) consistently overestimates by 5-15%.
NEAT — spontaneous physical activity outside formal exercise — is perhaps the most underappreciated metabolic variable. It includes fidgeting, posture, walking to get coffee, gesturing while talking, and thousands of micro-movements daily. NEAT can vary by up to 2,000 calories per day between individuals of the same weight, according to research by James Levine at the Mayo Clinic. This enormous variance explains why two people eating identical diets can have vastly different body composition outcomes. Desk jobs have dramatically reduced NEAT compared to historical labor patterns, contributing to population-level weight gain beyond simple overconsumption.
Metabolic adaptation is the body's defense mechanism against caloric restriction. When in a sustained deficit, the body reduces BMR by 10-25% through hormonal changes — lowering thyroid hormone output, reducing leptin (the satiety hormone), and increasing ghrelin (hunger hormone). This is why people on long-term calorie restriction eventually plateau: their TDEE decreases to match their intake. The phenomenon, called 'adaptive thermogenesis,' was documented in Ancel Keys's landmark 1944 Minnesota Starvation Experiment and is central to understanding why extreme diets fail long-term.
Activity multipliers used in TDEE calculators (1.2 for sedentary, up to 1.9 for very active) are based on research by Wier et al. and validated through doubly-labeled water studies — the gold standard for measuring real-world energy expenditure. In this technique, subjects drink water with heavy isotopes of hydrogen and oxygen; the differential washout rate reveals CO₂ production and thus caloric expenditure over days or weeks without any behavioral interference. Doubly-labeled water studies consistently find that self-reported exercise dramatically overstates actual caloric burn, which is why fitness tracker calorie estimates are notoriously unreliable.