BMI Calculator
Enter your height and weight to instantly calculate your Body Mass Index (BMI), see your BMI category, and understand your healthy weight range. Based on World Health Organization (WHO) adult classification standards.
Your Details
Calculate Body Fat % (Optional)
BMI Assessment
Enter your biometrics to calibrate focused results.
This tool provides educational estimates only and is not medical advice. Consult a qualified healthcare professional before making major nutrition, weight-loss, or exercise decisions.
Welcome Back
Last Plan Generated: --Your Personalized Report
Complete your details above and create your personalized plan to view your results.
Your complete personalized report will appear here after you create your plan.
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To lose 0.5 kg per week.
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Target:--
Your measurements indicate severe underweight status. This tool cannot provide weight-loss recommendations for this profile.
Maintenance-level calorie targets are shown instead. Please consult a qualified healthcare professional before making any dietary changes.
Your BMI falls below the normal range. Weight-loss recommendations may not be appropriate. Consider consulting a qualified healthcare professional.
Aggressive weight-loss pace has been disabled. Your calorie deficit has been limited to a maximum of 300 kcal/day for your safety.
Nutrition and calorie needs for individuals under 18 may differ from adult recommendations. Results should be reviewed with a parent, guardian, or healthcare professional.
Aggressive calorie deficits have been capped at 300 kcal/day. This tool is designed for general adult use.
You are already at your selected target weight. Maintenance recommendations are shown.
Your current weight matches your target. Calorie targets reflect your maintenance energy expenditure.
Weight Projection
Your daily targets: water intake recommendations, step goal, macro split, and calorie deficit guide
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Based on 35 ml per kg body weight baseline, adjusted for activity level and goal.
Formula: (Weight in kg * 35 ml) + Activity Adjustments--
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Supports calorie expenditure and long-term weight management.
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WHO recommends a minimum of 150 minutes of moderate-intensity physical activity per week for adults.
Your 7-Day Meal Plan
Portion sizes are dynamically optimized to align as closely as practical with your personalized calorie and macronutrient targets while using realistic serving sizes appropriate for your selected dietary preferences, region, and budget.
Nutrition estimates are based on established food composition databases and standard serving references. Actual values may vary due to ingredient brands, regional food products, preparation methods, recipes, and natural food variability.
Food exclusions personalize meal suggestions but do not guarantee an allergen-free meal plan. Always review ingredient labels carefully and consult a qualified healthcare professional if you have severe food allergies, medical conditions, or specific dietary requirements.
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--Your Personalized Nutrition Report is Ready
Your Personalized Nutrition Report Includes
- ✓7-Day Meal Plan
- ✓Weight Goal Timeline & Estimated Goal Date
- ✓Daily Calorie & Macro Targets
- ✓Grocery Shopping List
- ✓Water Intake & Activity Goals
- ✓Personalized Health Summary
- ✓Recommended Portion Sizes
Generate Your Personalized Nutrition Report
We've calculated your calories, macros, hydration targets, activity goals, and projected timeline. Generate your customized meal plan tailored to your preferences.
Why This Plan Works
Scientifically Calibrated Calculations
Used as the core BMR predictor, validated by clinical reviews as the most consistent baseline predictor in modern weight management.
BMR = 10*W(kg) + 6.25*H(cm) - 5*A(y) + s (+5 Male, -161 Female)Computes body fat percent dynamically from waist, neck, and height dimensions without requiring bioelectrical impedance scales.
Male: 86.01*log10(Waist-Neck) - 70.041*log10(Height) + 36.76Female: 163.205*log10(Waist+Hip-Neck) - 97.684*log10(Height) - 78.387Classifies BMI indexes into underweight, normal weight, overweight, and obese ranges as documented by the World Health Organization.
BMI = Weight(kg) / (Height(m))^2Why These Formulas Are Trusted
How the BMI Calculator Works
BMI (Body Mass Index) is a widely used screening metric that estimates your weight status based on height and weight. The calculator uses the standard WHO formula:
BMI = weight (kg) ÷ height² (m²)BMI = 703 × weight (lbs) ÷ height² (in²)After calculating your BMI value, the calculator matches it to WHO adult weight classification thresholds to display your category and healthy weight range.
BMI Categories for Adults
The World Health Organization defines the following BMI classifications for adults aged 18 and older. These thresholds apply equally to men and women:
| BMI Range | Classification | Associated Health Risk |
|---|---|---|
| < 18.5 | Underweight | Low (Risk of nutritional deficiencies) |
| 18.5 – 24.9 | Normal (Healthy Weight) | Minimal (Optimal range) |
| 25.0 – 29.9 | Overweight | Increased |
| 30.0 – 34.9 | Obese (Class I) | High |
| 35.0+ | Severely Obese (Class II & III) | Extremely High |
Source: World Health Organization (WHO) Global BMI Classification Standards for Adults.
Understanding Your Healthy Weight Range
Your healthy weight range is the span of body weights that corresponds to a BMI between 18.5 and 24.9 for your specific height. For example, a person who is 175 cm (5 ft 9 in) tall has a healthy weight range of approximately 56.6 to 76.3 kg (125 to 168 lbs). The calculator above displays your personal healthy weight range automatically.
Limitations of BMI
BMI is a useful population-level screening estimate but has recognized limitations when applied to individuals:
Does Not Measure Body Fat
BMI cannot distinguish between muscle mass and fat tissue. A muscular athlete and a sedentary person of the same height and weight may receive identical BMI values despite very different body compositions.
Ignores Fat Distribution
Where fat is stored (abdomen vs. hips) matters for health risk. BMI does not account for central adiposity (visceral fat), which is an independent health risk factor.
May Misclassify Athletes
Highly muscular individuals, bodybuilders, and elite athletes often fall into the overweight BMI range despite having low body fat and high fitness levels.
Not for Children or Pregnancy
Standard adult BMI thresholds do not apply to children, teenagers, or pregnant women. Age- and sex-specific growth charts are used for pediatric assessment.
BMI vs Body Fat Percentage
BMI is an indirect proxy calculated from height and weight alone. Body fat percentage directly measures how much of your total body mass is composed of fat tissue versus lean mass (muscle, bone, water). For a more complete picture of body composition, use our Body Fat Calculator, which uses the validated US Navy circumference method to estimate your body fat percentage.
What to Do After Calculating Your BMI
BMI is a starting point. Turn your BMI result into an actionable health and nutrition plan using our free tools:
To act on your BMI result, use the Food Calorie Calculator to see the calories, protein, carbs and fat in 300 common foods and plan meals that match your target intake.
Why Use This Calculator?
Recommended Next Step
Common BMI Calculator Questions
What is BMI?
BMI (Body Mass Index) is a numerical value calculated from your height and weight. It is used as a screening estimate to broadly classify an adult's weight category — Underweight, Normal, Overweight, or Obese — based on WHO population reference standards.
How is BMI calculated?
BMI is calculated by dividing your weight in kilograms by the square of your height in metres: BMI = weight (kg) ÷ height² (m²). For imperial measurements: BMI = 703 × weight (lbs) ÷ height² (in²).
What is a healthy BMI?
For adults aged 18 and over, a BMI between 18.5 and 24.9 is classified as a healthy (normal) weight according to the World Health Organization (WHO). A BMI below 18.5 is underweight; 25–29.9 is overweight; 30 and above is in the obese range.
What do BMI categories mean?
BMI categories are population-level screening bands. Underweight (below 18.5) may indicate nutritional risk. Normal weight (18.5–24.9) is associated with the lowest risk range. Overweight (25–29.9) indicates increased risk. Obese (30+) is associated with higher health risk. These are screening indicators, not diagnoses.
What is a healthy weight for my height?
A healthy weight range for your height is the range of body weights that correspond to a BMI between 18.5 and 24.9. The calculator above displays your personal healthy weight range after you enter your height.
Is BMI accurate for muscular people?
BMI does not distinguish between lean muscle mass and body fat. Highly muscular or athletic individuals may have a BMI in the overweight or obese range despite having low body fat. In such cases, additional measures like body fat percentage provide more relevant information.
What is the difference between BMI and body fat percentage?
BMI is an indirect estimate based only on height and weight. Body fat percentage measures the actual proportion of fat tissue in the body and is considered a more precise indicator of body composition. Our Body Fat Calculator uses the US Navy method to estimate body fat percentage directly.
Can BMI tell me how many calories I should eat?
No. BMI reflects a weight-height relationship but does not account for your metabolism, activity level, or energy needs. Use our free Calorie Calculator to estimate your daily calorie requirements based on your BMR and activity level.
What should I do after calculating my BMI?
Once you know your BMI category, useful next steps include calculating your daily calorie needs, estimating your body fat percentage, reviewing your macronutrient targets, or planning a goal weight and timeline using the dedicated tools linked below.
Medical Disclaimer: BMI results are screening estimates based on population-level reference standards and do not constitute a medical diagnosis. BMI does not directly measure body fat, muscle mass, or individual health status. Consult a qualified physician or registered dietitian for personalized clinical guidance.