//
Calculate your Basal Metabolic Rate (BMR) using the Mifflin-St Jeor equation and determine total daily energy expenditure (TDEE) across activity levels.
Calories burned at complete rest to support breathing, circulation, and vital organ function.
69.7 kcal/hr
2,009 kcal
1,724 kcal
2,009 kcal/day
100% of TDEE energy balance1,509 kcal/day
-500 kcal/day sustainable deficit1,759 kcal/day
-250 kcal/day gentle deficit2,259 kcal/day
+250 kcal/day lean surplusDaily maintenance calorie requirements across all physical activity tiers.
| Activity Tier | Description | Multiplier | Daily Energy (kcal) |
|---|---|---|---|
| Sedentary | Desk job, little to no regular exercise | 1.2x | 2,009 kcal/day |
| Lightly Active | Light exercise or sports 1–3 days/week | 1.375x | 2,301 kcal/day |
| Moderately Active | Moderate exercise or sports 3–5 days/week | 1.55x | 2,594 kcal/day |
| Very Active | Hard exercise or sports 6–7 days/week | 1.725x | 2,887 kcal/day |
| Extra Active | Very intense exercise, training 2x/day, or physical job | 1.9x | 3,180 kcal/day |
Official summary of physiological profile, basal metabolic rate, and maintenance targets.
Print metabolic statements, export calorie targets to CSV/JSON, or copy summary notes.
Formula Used for BMR Computation:
Scientific Context:
Based on the Mifflin-St Jeor equation, a 25-year-old male weighing 70 kg and measuring 175 cm has an estimated Basal Metabolic Rate of 1,674 kcal/day at complete rest. With a sedentary lifestyle (1.2x multiplier), estimated daily energy expenditure (TDEE) is ~2,009 kcal/day.
| Profile Scenario | Computed BMR Output |
|---|---|
| age : 25, gender : male , weight : 70, height : 175 | BMR: ~ 1,674 kcal/day (Mifflin-St Jeor) |
Basal Metabolic Rate (BMR) Calculator. Calculate your Basal Metabolic Rate (BMR) to discover the baseline calories your body burns at rest to maintain essential vital functions. ZechKit provides this tool completely free and online, optimized for instant, accurate computations directly inside your web browser.
Basal Metabolic Rate (BMR) represents the minimum daily energy expenditure (calories) required to maintain vital physiological processes—such as breathing, circulation, cellular repair, and brain function—while at complete physical and digestive rest.
Mifflin-St Jeor Equation: For Men: BMR = (10 × weight in kg) + (6.25 × height in cm) − (5 × age in years) + 5. For Women: BMR = (10 × weight in kg) + (6.25 × height in cm) − (5 × age in years) − 161.
Metabolic Share: BMR accounts for roughly 60% to 75% of total daily energy expenditure for most non-athletic adults, with the remainder burned through physical activity and food digestion.
Dietary Foundation: Knowing your baseline BMR ensures you do not set aggressive calorie deficits below your essential resting metabolic needs.
Which equation is most accurate for estimating BMR?
The Mifflin-St Jeor equation is widely regarded as the most reliable BMR formula for healthy individuals across varied body compositions.
