Calculator

BMI Calculator

Calculate your Body Mass Index and body fat percentage. Units: Metric, US or St/lb.

Result
BMI24.5
CategoryNormal
Body fat %20.1%
1218.5253040
1240
Healthy weight range56.7 – 76.3 kg
≈ 124.9 – 168.1 lb

Maintain this healthy range with a balanced plate, good sleep and regular movement.

BMI and body fat % are screening tools only. Consult a health professional for personalised advice.

What is Body Mass Index?

Body mass index (BMI) is a simple measure of weight relative to height used to classify underweight, normal weight, overweight and obesity in adults.

Illustration showing BMI categories: normal, overweight, obese

How BMI is calculated

The formula is BMI = weight (kg) / height2 (m2). You can also use pounds and inches with the same calculator.

BMI chart for a range of heights and weights

BMI categories

Limitations

BMI does not directly measure body fat and may misclassify muscular or elderly individuals. Consult a health professional for a full assessment.

Source: Wikipedia

Guide

Understanding Body Mass Index

BMI compares weight to height to estimate body fat. QuickCalc supports metric, US customary and stone inputs, then converts everything into the universal BMI formula so you can benchmark yourself against WHO categories.

  • Supports metric, imperial and st/lb conversions automatically.
  • Calculates BMI, estimated body-fat percentage and healthy weight ranges.
  • Highlights the category you fall into with context-sensitive advice.

The BMI formula

We apply BMI = weight / height^2 with weight in kilograms and height in metres. Imperial and stone inputs are converted behind the scenes before applying the calculation so you always get a consistent result.

Body-fat estimate & ranges

Using the Deurenberg equation, we approximate body-fat percentage based on BMI, age and gender. We also show the healthy weight span that corresponds to a BMI between 18.5 and 24.9 so you can see realistic targets.

Limitations

BMI is a screening tool—it does not account for muscle mass or body composition. Always consult a healthcare professional before making major changes. Use BMI as a conversation starter, not a diagnosis.

Source: CDC Healthy Weight – BMI