BMI 42.5: What It Means and What to Do
A body mass index of 42.5 places you in the Obese Class III category according to WHO and CDC standards. The average BMI for US adults is 29.8 (men: 29.4, women: 30.1).
BMI Scale Position
Your BMI: 42.5 — Very high risk; associated with significantly reduced life expectancy
BMI Category
Obese Class III
Healthy BMI Range
18.5–24.9
BMI to Lose to Reach Normal
17.6 BMI
Approx. Lbs to Lose (5ft9 ref)
~139 lbs
Weight Loss Timeline to Reach Normal BMI (5'9" reference)
A BMI of 42.5 at 5'9" corresponds to approximately 288 lbs. Reaching the midpoint of the normal range (BMI 22) at this height requires losing roughly 139 lbs.
−500 cal/day
139 weeks
32.1 months
1.00 lbs/week
−750 cal/day
93 weeks
21.4 months
1.50 lbs/week
FDA recommendation: 1–2 lbs/week. Deficits over 1,000 cal/day require medical supervision. Actual height and weight vary; use the BMI Calculator for your exact numbers.