🔥 BMR Calculator

Calculate your Basal Metabolic Rate — calories your body burns at rest.

Calculate Now

What is BMR Calculator?

Basal metabolic rate is the number of calories your body burns just to keep essential functions running — breathing, circulating blood, repairing cells, and maintaining organ temperature — while you're completely at rest, not the calories used during a workout or even a walk to the kitchen. This calculator estimates that resting energy cost from your weight, height, and age, giving you a baseline figure that most diet and fitness planning starts from. Trainers, dietitians, and calorie-tracking apps all lean on a BMR number before adding activity on top of it, so knowing your own figure helps you make sense of any calorie target you're given elsewhere.

Mifflin-St Jeor Formula

Calculator King uses the Mifflin-St Jeor equation, widely regarded as more accurate for modern populations than the older Harris-Benedict formula it replaced:

Men: BMR = 88.362 + (13.397 × weight in kg) + (4.799 × height in cm) − (5.677 × age in years)
Women: BMR = 447.593 + (9.247 × weight in kg) + (3.098 × height in cm) − (4.330 × age in years)

Worked Example

Take a 30-year-old man weighing 70 kg and standing 170 cm tall:

BMR = 88.362 + (13.397 × 70) + (4.799 × 170) − (5.677 × 30)
BMR = 88.362 + 937.79 + 815.83 − 170.31
BMR ≈ 1,672 kcal/day

That means his body burns roughly 1,672 calories a day even if he stayed in bed the entire time — before factoring in a single step of walking, a workout, or digestion.

How to Use This Calculator

  1. Enter your current body weight in kilograms.
  2. Enter your height in centimetres.
  3. Enter your age in completed years.
  4. Press Calculate to see your estimated resting calorie burn.

Things to Keep in Mind

BMR is only your resting number — it doesn't include the calories you burn walking, exercising, or even fidgeting through the day. For a complete daily calorie target you'll want to multiply this figure by an activity factor, which is exactly what our calorie calculator does. Muscle mass, thyroid function, genetics, and even sleep quality can shift your real BMR slightly above or below this formula-based estimate, so treat it as a well-informed starting point rather than an exact lab measurement.

💡 Tip: If your goal is fat loss, avoid eating below your BMR for long stretches — it can slow your metabolism and make sustainable weight loss harder. Speak with a doctor or dietitian before starting any aggressive calorie deficit.

Once you have your BMR, head over to the Calorie Calculator to turn it into a full daily calorie target based on how active you actually are.

📅 Last reviewed: July 2026 · Formulas verified against RBI/SEBI/IT Dept guidelines.