BMI Calculator
Calculate your Body Mass Index from your height and weight, and see your healthy weight range.
Calculate Your BMI
Your BMI
BMI Category
Healthy Weight Range
Quick Summary
BMI (Body Mass Index) is a simple measure that uses your height and weight to estimate whether your weight is healthy.
This calculator also shows the healthy weight range for your height based on standard BMI categories.
How to Use This Calculator
- Enter your height in centimetres.
- Enter your weight in kilograms.
- Click Calculate BMI to see your BMI value and category instantly.
What is BMI?
Body Mass Index (BMI) is a widely used screening measure that estimates body fat based on a person's height and weight. It is commonly used by doctors, fitness professionals and individuals as a quick indicator of whether someone is underweight, at a healthy weight, overweight or obese.
While BMI is a useful general guideline, it does not directly measure body fat percentage and may not account for factors like muscle mass, bone density, age and sex. It should be used alongside other health assessments rather than as a standalone diagnosis.
Formula
BMI = Weight (kg) ÷ [Height (m)]²
Healthy Weight Range = BMI 18.5 to 24.9 × [Height (m)]²
Worked Example
Height = 170 cm = 1.70 m
Weight = 65 kg
BMI = 65 ÷ (1.70 × 1.70)
BMI = 65 ÷ 2.89 ≈ 22.5
Category = Normal Weight
BMI Categories
Below 18.5 → Underweight
18.5 to 24.9 → Normal Weight
25.0 to 29.9 → Overweight
30.0 and Above → Obese
Understanding Your BMI Result
A BMI in the underweight range may indicate insufficient nutrient intake and could be associated with a weakened immune system, fatigue, or nutrient deficiencies. Increasing calorie intake with nutrient-dense foods and consulting a healthcare provider can help.
A BMI in the normal weight range is generally associated with a lower risk of weight-related health conditions. Maintaining a balanced diet and regular physical activity helps sustain this range.
A BMI in the overweight range may increase the risk of conditions such as high blood pressure, type 2 diabetes and heart disease over time. Gradual lifestyle changes involving diet and exercise are often recommended.
A BMI in the obese range is associated with a higher risk of several chronic conditions. Consulting a healthcare professional for a personalized plan is generally advised.
Benefits
- Quick estimate of healthy weight status.
- See your personalized healthy weight range.
- Track changes in weight over time.
- Useful starting point for fitness goals.
- Free, instant and easy to use.
Practical Use Cases
- Getting a quick, general sense of whether your weight is in a healthy range for your height.
- Tracking BMI over time alongside other health habits, such as sleep and study-life balance.
Common Mistakes to Avoid
- Mixing up centimetres and metres for height, which throws the whole calculation off by a factor of 100.
- Treating BMI as a complete health verdict — it doesn't account for muscle mass, bone density, age or body composition.
- Not re-checking BMI periodically — a single reading is a snapshot, not a trend.
Frequently Asked Questions
BMI is a general screening tool and may not be fully accurate for athletes, pregnant women, children, or older adults, as it does not distinguish between muscle and fat mass.
A BMI between 18.5 and 24.9 is generally considered a healthy range for most adults.
It is calculated by applying the BMI range of 18.5 to 24.9 to your height, giving the corresponding minimum and maximum healthy weight in kilograms.