TDEE from BMR and Activity Factor
Multiplies basal metabolic rate in kcal by an activity factor between 1.2 (sedentary) and 1.9 (athlete) to give total daily energy expenditure in kcal per day.
TDEE (kcal/dia)
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TDEE with activity factor: total daily energy expenditure
TDEE (Total Daily Energy Expenditure) is an estimate of how many calories your body burns over a full day. Once you know your BMR (Basal Metabolic Rate, the energy you use at rest), the math is just TDEE = BMR · activity factor. Each activity factor rolls together your exercise, the calories you burn moving around without exercising (NEAT), and the thermic effect of food. The usual brackets are sedentary 1.2 (desk job, no training), light 1.375 (1–3 sessions a week), moderate 1.55 (3–5 a week), active 1.725 (6–7 intense sessions a week), and very active 1.9 (athletes training twice a day or doing hard manual labor). NEAT covers things like fidgeting, walking and standing, and it swings wildly from one person to the next, up to 2,000 kcal/day apart. That's largely why the same BMR ends up producing such different real-world TDEE values. As an example, a BMR of 1,600 kcal at moderate activity (1.55) lands at a TDEE of 2,480 kcal/day.
Applications: nutrition, body recomposition, sports
Any personalized diet starts from your TDEE. Drop 300–500 kcal below it to lose fat, eat right at it to maintain, or go 200–400 kcal over for a lean bulk. It shows up in body recomposition too, where you cycle deficits and surpluses around TDEE, and in endurance sports, where carb intake is what's left after protein and fat (TDEE − protein − fat), converted to grams. Clinical nutrition leans on it as well. Watch out for the activity factor, though, because it's where most of the error creeps in and people almost always pick too high. If your weight isn't moving the way you expected after 3–4 weeks, that multiplier was off. Trust your real data over the table and adjust.
FAQ
Sedentary or light for someone who walks the dog daily? Go with light. Sedentary really means going from the office chair to the couch and not much else. If you walk 30 minutes or more a day, or your job keeps you on your feet, you're at least light (1.375).
Should I count workouts twice if I use 1.55 and also log exercise calories? That's double-counting, so no. Pick one approach: either use the multiplier and skip logging your workouts, or stay at 1.2–1.375 and add the workout calories on top separately.
Why is my actual TDEE lower than the formula? Usually one of three things: adaptive thermogenesis, where your metabolism slows down while dieting; NEAT you overestimated; or snacks that slipped past your tracking. Recheck the number every 2–4 weeks against your weight trend.
Does TDEE change with age? It does. After 30, BMR tends to slip about 1–2% per decade, mostly because you lose lean mass. Keep up strength training and you can hold off nearly all of that decline.
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The results provided by this tool are for general informational and educational purposes only and do not constitute professional, financial, medical, legal, tax or accounting advice. Always confirm important decisions with a qualified professional and official sources.