BMI Calculator
Calculate Body Mass Index (BMI) using US Imperial or Metric units, with WHO health classification and ideal weight range.
BMI Calculator
WHO & CDC Standard CompliantThe Body Mass Index (BMI) Calculator can be used to calculate BMI value and corresponding weight status while taking age into consideration. Use the 'Metric Units' tab for the International System of Units or the 'Other Units' tab to convert units into either US or metric units. Note that the calculator also computes the Ponderal Index in addition to BMI, both of which are discussed below in detail.
• Choose your measurement system: US Units (feet, inches, pounds), Metric Units (centimeters, kilograms), or Other Units (stone, pounds).
• Enter your Age (2 - 120) and select your biological Gender. For children & teens (ages 2–19), BMI percentiles are also evaluated.
• Click Calculate BMI to generate your BMI value, clinical status category, color-coded radial speedometer, ideal healthy weight range, BMI Prime, and Ponderal Index.
Equivalent: 177.8 cm (1.78 m)
Equivalent: 72.6 kg (11 st 6.0 lbs)
A BMI of 23.0 kg/m² indicates that you are at a healthy weight for your height. Maintaining this range is associated with lower cardiovascular and metabolic risks.
BMI Radial Speedometer
Your body weight is within the healthy BMI range for your height.
Related Health & Fitness Calculators
Deep Dive: Understanding BMI, Ponderal Index & Healthy Weight
The World Health Organization (WHO) defines Body Mass Index (BMI) as a simple index of weight-for-height that is commonly used to classify underweight, normal weight, overweight, and obesity in adult populations (aged 20 and older).
| BMI Range (kg/m²) | WHO Classification | BMI Prime | Health Risk Profile |
|---|---|---|---|
| < 16.0 | Severe Thinness | < 0.64 | High risk of undernutrition and immune suppression |
| 16.0 – 16.9 | Moderate Thinness | 0.64 – 0.67 | Moderate nutritional deficiency risk |
| 17.0 – 18.4 | Mild Thinness | 0.68 – 0.73 | Mild risk of low bone density and nutrient depletion |
| 18.5 – 24.9 | Normal (Healthy Weight) | 0.74 – 0.99 | Lowest risk of cardiovascular and metabolic illness |
| 25.0 – 29.9 | Overweight (Pre-obese) | 1.00 – 1.19 | Increased risk of hypertension and type 2 diabetes |
| 30.0 – 34.9 | Obese Class I (Moderate) | 1.20 – 1.39 | High risk of cardiovascular disease and sleep apnea |
| 35.0 – 39.9 | Obese Class II (Severe) | 1.40 – 1.59 | Very high risk of joint, vascular, and metabolic comorbidities |
| ≥ 40.0 | Obese Class III (Morbid) | ≥ 1.60 | Extremely high risk; clinical supervision recommended |
BMI = Weight (kg) / [Height (m)]²BMI = 703 × Weight (lbs) / [Height (in)]²Understanding BMI Calculator & Formula
The BMI Calculator on CalculatorScale.com is engineered to deliver instant, mathematically verified calculations conforming strictly to standard institutional equations. Whether planning long-term investments, managing household budgets, tracking clinical fitness targets, analyzing academic genetics, calculating veterinary dosages, or converting dimensional units, every calculation updates dynamically in real time without lag.
Every formula used in this tool adheres to certified international standards, including World Health Organization biometric metrics, veterinary clinical guidelines, NIST physical conversion constants, and standard biological equations. Results are computed entirely client-side inside your browser with complete data privacy, ensuring your sensitive numbers and statistics never leave your device.
Our calculators are 100% free with no registration, subscriptions, or paywalls required. You can toggle between imperial and metric units, customize input parameters, export calculation summaries, or embed this calculator directly into your own website or blog.
How to Use the BMI Calculator
- 1 Choose your preferred measurement system (US Units or Metric).
- 2 Select your gender and enter your age.
- 3 Enter your height and weight.
- 4 Instantly view your calculated BMI, category indicator, and healthy weight range.
BMI Calculator — Frequently Asked Questions
Q1 What is a normal BMI range? ▾
According to the World Health Organization (WHO), a BMI between 18.5 and 24.9 is considered normal or healthy weight for adults. Under 18.5 is underweight, 25-29.9 is overweight, and 30 or higher indicates obesity.
Q2 Is BMI accurate for athletes and bodybuilders? ▾
BMI does not directly measure body fat and can overestimate body fat in athletes or individuals with high muscle mass, and underestimate body fat in older adults who have lost muscle mass.
Q3 How is BMI calculated for adult men and women? ▾
BMI is calculated with the same formula for both adult men and women: weight in kilograms divided by height in meters squared (or 703 × weight in pounds divided by height in inches squared).
Q4 What is the difference between BMI and Body Fat Percentage? ▾
BMI calculates weight relative to height without distinguishing between muscle, bone, and fat. Body fat percentage directly measures the proportion of adipose fat tissue relative to total body weight.
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