BMI & BMR Calculator
Calculate Body Mass Index and Basal Metabolic Rate instantly
BMI Calculator
BMI Value
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BMR Calculator
Daily Calorie Needs (BMR)
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Calories needed at rest
BMI Categories
Underweight
BMI < 18.5
Normal
BMI 18.5-24.9
Overweight
BMI 25-29.9
Obese
BMI ≥ 30
What Do BMI and BMR Actually Measure?
BMI (Body Mass Index) is your weight relative to your height, used as a rough screening indicator for the underweight/normal/overweight/obese ranges. BMR (Basal Metabolic Rate) is how many calories your body burns at complete rest just to keep you alive — breathing, circulation, cell repair — before any activity is added on top.
Enter your height, weight, age, and gender, and this calculator returns both instantly, entirely in your browser.
Why Use This BMI & BMR Calculator
📊 Both Metrics Together
BMI and BMR from the same inputs — no need for two separate calculators.
⚡ Instant Results
Results update live as you adjust height, weight, age, or gender.
🔒 Private Health Data
Calculations run locally — your health details are never sent anywhere.
How to Calculate Your BMI and BMR
- Enter your height (cm) and weight (kg) for the BMI result.
- Add your gender and age in the BMR section — both factor into the Mifflin-St Jeor formula this tool uses.
- Read your results: BMI as a number and category (underweight/normal/overweight/obese), and BMR as calories/day at complete rest.
Using Your Results Correctly
1. BMI doesn't account for muscle mass
A muscular, athletic person can show a high BMI despite low body fat — BMI is a population-level screening tool, not a precise individual diagnosis.
2. Your BMR isn't your total daily calorie need
BMR is calories at complete rest. To find your actual daily need (TDEE), multiply BMR by an activity factor (roughly 1.2 for sedentary, up to 1.9 for very active) to account for movement and exercise.
3. Use it as a starting point, not medical advice
Both numbers are useful general guides for nutrition and fitness planning — for anything involving a specific health condition, talk to a doctor or dietitian.
Frequently Asked Questions (FAQ)
Q: What BMI range is considered "normal"?
A: The commonly used WHO ranges are: under 18.5 underweight, 18.5-24.9 normal, 25-29.9 overweight, and 30+ obese — though these bands don't account for muscle mass or body composition.
Q: What formula does this tool use for BMR?
A: The Mifflin-St Jeor equation — widely regarded as more accurate than the older Harris-Benedict formula for most adults.
Q: Should I eat exactly my BMR in calories?
A: No — eating only your BMR would starve your body of energy for daily activity. Use your BMR × activity level (TDEE) as your maintenance calorie target instead.