Adult planning estimate only. Not suitable for children, pregnancy, diagnosis, treatment, or an individualized calorie prescription. Consult a qualified clinician or dietitian for medical or nutrition decisions.
Calculation details
Adult screening estimate only, not a diagnosis. Body composition, age, pregnancy, medical history, and population-specific risk can change interpretation; discuss health decisions with a qualified clinician.
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Use this result
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What does this calculator estimate?
A BMR and TDEE calculator estimates the calories you burn at rest (basal metabolic rate) and per day with activity. Enter your age, sex, weight, height, and activity level to see both numbers.
- Mifflin-St Jeor: BMR = 10w + 6.25h − 5a (+5 male / −161 female)
- TDEE = BMR × activity multiplier
- TDEE is the maintenance-calorie estimate
What BMR and TDEE measure
Basal metabolic rate is the energy your body uses at rest to stay alive — breathing, heartbeat, temperature. TDEE adds your daily activity on top, giving the calorie intake that would maintain your current weight.
Limitations to watch for
The Mifflin-St Jeor equation is an estimate for average adults; muscle mass, genetics, and hormones shift the real numbers. Activity multipliers are self-selected and easy to overestimate. The calculator is a starting point — track and adjust from real results.
How to use it in practice
Use TDEE as your maintenance target. To lose weight, eat below it (a 300–500 kcal deficit is a common start); to gain, eat above. Recalculate as your weight changes. Pick your activity level honestly — desk jobs are sedentary even with workouts.
- Enter age, sex, weight, and height.
- Choose the activity level closest to your typical week.
- The tool computes BMR and TDEE.
How this calculator works
Formula
Mifflin-St Jeor BMR: male = 10×weight(kg) + 6.25×height(cm) − 5×age + 5; female = 10×weight(kg) + 6.25×height(cm) − 5×age − 161. TDEE = BMR × activity multiplier: 1.2 sedentary, 1.375 light, 1.55 moderate, 1.725 very active, 1.9 extra active.
Worked example
A 30-year-old man, 80 kg, 180 cm: BMR = 800 + 1,125 − 150 + 5 = 1,780 kcal/day. With moderate activity (1.55), TDEE ≈ 2,759 kcal/day.
Assumptions to verify
- The Mifflin-St Jeor equation applies (adults 18–100).
- The chosen activity multiplier reflects the user's lifestyle.
- Results are estimates for planning, not medical prescriptions.
Frequently asked questions
What is BMR?
Basal metabolic rate — the calories your body burns at complete rest just to maintain life. It's typically the largest share of your daily burn.
What is TDEE?
Total daily energy expenditure — BMR plus activity and digestion. Eating at TDEE maintains weight; below it loses, above it gains.
How is BMR calculated?
The Mifflin-St Jeor equation: 10×weight(kg) + 6.25×height(cm) − 5×age + 5 (men) or − 161 (women).
What activity multiplier should I pick?
Be honest: 1.2 for desk jobs, 1.375 light exercise 1–3 days/week, 1.55 moderate 3–5 days, 1.725 very active, 1.9 extra active. Overestimating activity is common.
How many calories should I eat to lose weight?
Start with TDEE minus 300–500 kcal/day for a sustainable ~0.5–1 lb/week loss, and adjust based on real progress.
Is this accurate?
It's a strong population estimate, but individual results vary with muscle mass and metabolism. Track your weight for 2–4 weeks and adjust.
Do I need to recalculate?
Yes — as your weight changes by 5–10 lb, recalculate. BMR falls as you lose weight, so targets drift.
Cite this tool
BoringToolsKit. “BMR & TDEE Calculator.” boringtoolskit.com/bmr-tdee-calculator/ (reviewed 2026-08-25). Free to reference in articles, syllabi, and answer posts with a link.
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