Online BMI Calculator (Adults)
Fast BMI with healthy‑weight range, optional waist‑risk check, and a live range graph. For adults 20+ years.
BMI Calculator
Helps flag extra risk from central fat.
BMI: —
Category: —
Healthy BMI is 18.5–24.9. Your healthy weight range will appear after you enter height.
⚠️ For adults 20+ years. For children/teens, use an age‑and‑sex specific BMI tool. Results are estimates; muscle mass, ethnicity, pregnancy, and certain conditions can affect interpretation. Discuss with a clinician if unsure.
How is BMI calculated?
BMI = weight (kg) ÷ [height (m)]². Categories commonly used in adult care: <18.5 underweight, 18.5–24.9 healthy, 25–29.9 overweight, ≥30 obesity.
Why include waist circumference?
A larger waist suggests more visceral fat and higher health risk even at the same BMI. Many services flag increased risk at ≥94 cm in men and ≥80 cm in women, with very high risk at ≥102/≥88 cm.
References: CDC Adult BMI calculator/categories; NHS adult BMI guidance and waist thresholds.