BMR & Calorie Calculator
Estimate your basal metabolic rate (BMR), the calories you burn in a day at your activity level (TDEE), and calorie targets to lose, keep or gain weight. Works in pounds and feet/inches or metric.
Enter your sex, age, height and weight, then tap Calculate calories.
Daily calories by goal
For comparison, the revised Harris-Benedict equation gives a BMR of - kcal/day.
BMR and TDEE explained
Basal metabolic rate (BMR) is the energy your body uses at complete rest to keep your heart beating, breathe and hold its temperature. For most people it makes up roughly 60–70% of the calories burned in a day.
Total daily energy expenditure (TDEE) adds everything else: walking, work, exercise and digesting food. Eating about your TDEE keeps your weight stable; eating less leads to weight loss and eating more to weight gain. This calculator estimates TDEE by multiplying your BMR by an activity factor.
The formulas
Mifflin-St Jeor (main result)
- Men: 10 × weight (kg) + 6.25 × height (cm) − 5 × age + 5
- Women: 10 × weight (kg) + 6.25 × height (cm) − 5 × age − 161
Published by Mifflin and colleagues in 1990. A systematic review by the American Dietetic Association (now the Academy of Nutrition and Dietetics) found it the most accurate of the common equations for healthy adults, so it is the default here. US inputs are converted to kg and cm first (1 lb = 0.4536 kg, 1 in = 2.54 cm).
Revised Harris-Benedict (for comparison)
- Men: 88.362 + 13.397 × weight + 4.799 × height − 5.677 × age
- Women: 447.593 + 9.247 × weight + 3.098 × height − 4.330 × age
The 1919 Harris-Benedict equation as re-estimated by Roza and Shizgal in 1984. It usually comes out slightly higher than Mifflin-St Jeor.
Activity factors
| Activity level | Typical week | Factor |
|---|---|---|
| Sedentary | Desk job, little or no exercise | 1.2 |
| Lightly active | Light exercise 1–3 days | 1.375 |
| Moderately active | Moderate exercise 3–5 days | 1.55 |
| Very active | Hard exercise 6–7 days | 1.725 |
| Extra active | Daily intense training or a physical job | 1.9 |
Example: a 30-year-old man who is 5 ft 9 in (175.3 cm) and 160 lb (72.6 kg): BMR = 725.7 + 1,095.4 − 150 + 5 ≈ 1,676 kcal. Moderately active, his TDEE is about 1,676 × 1.55 ≈ 2,598 kcal a day.
Using your calorie targets
The lose and gain targets are 500 kcal below and above your TDEE. A 500 kcal daily deficit is often quoted as “1 lb a week” (the old 3,500 kcal rule), but research shows weight loss slows over time as your body adapts, so expect less than that after the first few weeks. To build muscle, a smaller surplus of 250–500 kcal combined with strength training is a common approach.
Don’t eat below your BMR
Cutting calories below your BMR for long periods makes muscle loss and rebound weight gain more likely. If the weight-loss target comes out below your BMR, the calculator warns you; in that case keep intake near your BMR and add activity instead. Check where you stand with the BMI Calculator and set a goal with the Ideal Weight Calculator.
Frequently asked questions
How can I raise my BMR?
Muscle burns more energy at rest than fat. Regular strength training and enough protein help preserve and build it.
Why is my smart scale or fitness tracker different?
Body-composition scales estimate BMR from measured lean mass, and trackers add their own
activity estimates. Equations that only use height, weight and age can differ, especially for very muscular or very lean people.
These are estimates for healthy adults. If you are pregnant or breastfeeding, have a medical condition, or are under 18, ask a doctor or registered dietitian before changing how much you eat.
Sources
- Mifflin MD et al., A new predictive equation for resting energy expenditure in healthy individuals, Am J Clin Nutr 1990;51:241–7.
- Frankenfield D et al., Comparison of predictive equations for resting metabolic rate in healthy nonobese and obese adults: a systematic review, J Am Diet Assoc 2005;105:775–89.
- Roza AM, Shizgal HM, The Harris Benedict equation reevaluated, Am J Clin Nutr 1984;40:168–82.
- Hall KD et al., Quantification of the effect of energy imbalance on bodyweight, Lancet 2011;378:826–37.