Total Daily Energy Expenditure (TDEE) is the total number of calories your body burns each day — from breathing and digestion to every step you take and every workout you finish. It's the single most important number in nutrition: eat below it to lose fat, at it to maintain your current weight, or above it to build muscle. Unlike oversimplified online calculators, this tool uses the Mifflin–St Jeor equation — the most validated BMR formula for the general population — and applies a scientifically grounded activity multiplier before calculating personalised calorie and macro targets for your specific goal.
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Mifflin–St Jeor Formula
The most accurate BMR equation for the general population, validated across multiple peer-reviewed studies. Consistently outperforms the older Harris–Benedict formula.
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Activity Multiplier
Your BMR is multiplied by a factor (1.2–1.9) based on how often you exercise. This accounts for NEAT (non-exercise activity), formal workouts, and your occupation.
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Fat Loss (–500 kcal)
A 500 kcal daily deficit creates ~0.5 kg of fat loss per week — the evidence-backed sweet spot for preserving muscle while losing fat at a sustainable rate.
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Lean Bulk (+300 kcal)
A modest 300 kcal surplus supports muscle protein synthesis while minimising fat gain — the preferred approach for anyone building muscle without a dramatic bulk-cut cycle.
How We Calculate Your TDEE
This tool uses the Mifflin–St Jeor equation — validated in multiple clinical studies as the most reliable BMR estimate for non-athlete adults.
- For men: BMR = (10 × kg) + (6.25 × cm) − (5 × age) + 5
- For women: BMR = (10 × kg) + (6.25 × cm) − (5 × age) − 161
- TDEE = BMR × activity multiplier (1.2 to 1.9)
- Fat loss target = TDEE − 500 kcal/day (~0.5 kg/week)
- Muscle gain target = TDEE + 300 kcal/day (lean bulk)
The Mifflin–St Jeor equation predicts BMR within ~10% for most adults. The activity multiplier introduces the most variability — if results don't match your experience after 2–3 weeks, adjust down by 100–150 kcal.
How to Use Your Macro Targets
Macronutrients are the three energy-yielding nutrients your body runs on. Getting the split right matters almost as much as total calories.
- Protein (4 kcal/g): Builds and preserves muscle. Aim for 1.6–2.2 g per kg of bodyweight. Go higher (2.0–2.4 g/kg) when in a calorie deficit.
- Carbohydrates (4 kcal/g): Primary fuel for high-intensity training and brain function. Source and timing matter more than quantity alone.
- Fats (9 kcal/g): Essential for hormones, brain health, and fat-soluble vitamins (A, D, E, K). Keep at 25–35% of total calories, favouring unsaturated sources.
Hitting your calorie target is step one. Hitting your protein target is step two. Everything else — carb/fat split, meal timing, food choices — comes after these two fundamentals are locked in.
Frequently Asked Questions
How accurate is a TDEE calculator?
TDEE calculators estimate within ±10–15% for most people. The Mifflin–St Jeor BMR formula is the most validated, but the activity multiplier is where error creeps in — most people overestimate their activity. Use the result as a starting point, track your weight for 2–3 weeks, and adjust by ±100–200 kcal based on real results.
Should I eat back exercise calories?
No — your TDEE already accounts for exercise. It is not the same as BMR. Eating back exercise calories (as some apps suggest) leads to double-counting, because the activity multiplier you selected already bakes in your training sessions.
How often should I recalculate my TDEE?
Recalculate every 4–6 weeks, whenever your weight changes by 3+ kg, or if you significantly increase or decrease your training volume. TDEE drops as you lose weight — recalculating prevents plateaus caused by a shrinking calorie gap.
What is the difference between BMR and TDEE?
BMR (Basal Metabolic Rate) is the calories you would burn in 24 hours doing absolutely nothing — the energy to keep your heart beating, lungs working, and temperature stable. TDEE multiplies BMR by your activity level to estimate how many calories you actually burn in a day of real life.
How many calories should I eat to lose fat?
A deficit of 300–500 kcal per day is the evidence-backed range for fat loss that preserves muscle. This produces 0.3–0.5 kg of fat loss per week. Larger deficits accelerate weight loss but significantly increase the risk of muscle loss, hormonal disruption, and metabolic adaptation.
Does TDEE change as I lose weight?
Yes — and this is why plateaus happen. As you lose weight, your body is smaller and burns fewer calories at rest. TDEE decreases by roughly 20–30 kcal for every kilogram lost. If you don't recalculate and adjust your intake, your deficit shrinks and weight loss stalls — even if your habits haven't changed.