BMR & TDEE Calculator (Daily Calorie Needs)
Calculate your basal metabolic rate (BMR) and total daily energy expenditure (TDEE) — the calories you burn at rest and with activity.
What this calculates
Your BMR is the energy you'd burn lying in bed all day — about 60–75 % of total daily calories for most people. TDEE multiplies BMR by an activity factor to estimate what you actually burn including movement and exercise. These two numbers anchor any deliberate weight goal: eat at TDEE to maintain, below it to lose, above it to gain.
Formula & how it works
This calculator uses the Mifflin-St Jeor equation, the most accurate for healthy adults. Men: BMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age + 5. Women: BMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age − 161. TDEE = BMR × activity multiplier: 1.2 sedentary, 1.375 light (1–3 days/week), 1.55 moderate (3–5 days), 1.725 very active (6–7 days), 1.9 athlete or physical job.
Worked example
A 35-year-old man, 80 kg, 180 cm, exercising 4× per week (moderate). BMR = 10 × 80 + 6.25 × 180 − 5 × 35 + 5 = 800 + 1125 − 175 + 5 = 1755 kcal. TDEE = 1755 × 1.55 ≈ 2720 kcal/day. Eating 2200 kcal would produce roughly 1 lb/week of fat loss; eating 3200 kcal would produce ~1 lb/week of gain.
Frequently asked questions
How accurate is this?
Mifflin-St Jeor is within ~10 % for most adults. Your real burn varies day to day with sleep, stress, food choice, and NEAT (non-exercise activity). Use this as a starting point; track your weight for 2–3 weeks and adjust by 100–200 kcal/day if you're not seeing expected change.
Should I subtract calories burned in exercise?
No — TDEE already includes them via the activity multiplier. Subtracting separately double-counts and is the #1 reason people overshoot a deficit. Pick the multiplier that matches your typical week and trust it.
Why does BMR drop as I lose weight?
BMR scales with body mass. As you lose weight, BMR drops by roughly 7 kcal per pound lost. That's why weight loss plateaus — your TDEE has fallen and the old deficit is no longer a deficit. Recalculate every 5–10 lbs.
Does muscle burn way more than fat at rest?
A little, not a lot. Per pound, muscle burns about 6 kcal/day at rest, fat about 2 kcal. So adding 10 lb of muscle adds maybe 40 kcal/day to BMR — meaningful over years, not transformative day to day.
Sources
Disclaimer: Informational only. Talk to a registered dietitian or physician before significant calorie restriction, especially if you have any medical condition.
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