BMI calculator (metric)
Enter height in centimetres and weight in kilograms.
BMI Calculator (Metric)
Instantly calculate your Body Mass Index using height in centimetres and weight in kilograms. Based on NHS guidelines.
How to use the BMI Calculator
- Enter your height in centimetres.
- Enter your weight in kilograms.
- Select Calculate to see your BMI and category.
Examples
- 170 cm, 70 kg → BMI = 70 / (1.70²) = 24.2 (Healthy).
- 160 cm, 90 kg → BMI = 90 / (1.60²) = 35.2 (Obese).
Formula
BMI = weight (kg) ÷ [height (m)]²
Categories (adults)
- < 18.5 — Underweight
- 18.5–24.9 — Healthy
- 25–29.9 — Overweight
- 30+ — Obese
Notes
- BMI is a general guide for adults (18+). It may not suit athletes, pregnant people, or those with high muscle mass.
- Results use metric units (cm, kg). Convert first if needed.
- This is not medical advice. If you have concerns about your weight or health, speak to a clinician.
Related tools
BMR & TDEE Calculator · BMI in Stones & Pounds (UK) · Percentage Calculator
Quick FAQ
Do I enter height in metres or centimetres?
Enter height in centimetres. The calculator converts to metres internally.
Is BMI suitable for children?
No. This tool is for adults. Children need age- and sex-specific growth charts.
What if I only know feet/inches or pounds?
Convert your height to cm and weight to kg, then calculate. (We’ll add direct imperial support soon.)