health Calculator

BMI & Ideal Body Weight Calculator

Calculate Body Mass Index (BMI), World Health Organization (WHO) weight status classification, and healthy ideal weight range.

Audited by UniqCalc Methodology Team • Formula Checked • Free & No Registration Required

Verified Mathematical Model & Formulation

BMI = weight_kg / (height_m)^2
Ideal Weight (Devine Male) = 50 kg + 2.3 kg × (height_in - 60)
Ideal Weight (Devine Female) = 45.5 kg + 2.3 kg × (height_in - 60)
Normal BMI Range = 18.5 to 24.9 kg/m²

Computes Body Mass Index via standard metric height-to-weight ratio and calculates estimated Ideal Body Weight (IBW) using the Devine formula.

Configurable Parameters & Standard Units

  • Biological Sex (1=Male, 2=Female): (Default: 1 count)
  • Height (cm): (Default: 178 cm)
  • Weight (kg): (Default: 78 kg)

Standard Worked Example & Practical Verification

Scenario: A female who is 165 cm (65 inches) tall weighing 72 kg.

Calculated Solution
BMI 26.5 (Overweight Class) | Ideal Target 50.4 - 67.8 kg

Practical Takeaway: A modest reduction of 4.5 kg brings this individual into the standard healthy, lower-risk BMI spectrum.

Frequently Asked Questions

What is a healthy BMI range for adults?

According to the World Health Organization, a normal and healthy adult BMI falls between 18.5 and 24.9. Below 18.5 is underweight, 25.0-29.9 is overweight, and 30+ is obese.

Why is BMI sometimes misleading for bodybuilders?

Muscle tissue is significantly denser than fat. Elite athletes and bodybuilders with high muscle mass and low body fat can score a high BMI while being exceptionally fit.