What is a healthy BMI range?

A healthy BMI typically falls between 18.5 and 24.9. Below 18.5 is considered underweight, and 25 or above is considered overweight or obese.

What BMI qualifies for bariatric surgery?

You may qualify for bariatric surgery if your BMI is 40 or higher, or 35 and higher with obesity-related conditions such as diabetes, high blood pressure, or sleep apnea.

Is BMI the only factor in weight-loss surgery eligibility?

No, BMI is one factor. Providers also consider your age, health history, and obesity-related conditions when determining eligibility for bariatric surgery.

Can muscle mass affect my BMI?

Yes. Athletes and muscular individuals may have a higher BMI due to muscle, not fat. That's why other tools like waist circumference or body composition tests are sometimes used.

BMI Calculator for Bariatric Surgery Candidates | BASS Bariatric Surgery Center

What Is BMI and Why Does It Matter?

BMI is a mathematical formula:

weight (lbs) ÷ height² (inches) × 703‍

It provides a quick way to classify your weight status:

Underweight: BMI < 18.5
Normal weight: BMI 18.5–24.9
Overweight: BMI 25–29.9
Obesity Class I: BMI 30–34.9
Obesity Class II: BMI 35–39.9
Obesity Class III: BMI ≥ 40

A BMI of 35 or higher may indicate that you qualify for bariatric surgery, especially if you also have health conditions related to obesity.

Color-coded BMI chart showing height on Y-axis, weight on X-axis, and BMI categories such as underweight, normal weight, overweight, and obesity.

Is BMI Always Accurate?

While BMI is a helpful screening tool, it isn’t perfect. It doesn’t distinguish between fat and muscle. That means:

Athletes may have a high BMI due to muscle, not fat.
Older adults may have a normal BMI but still carry excess fat.

That’s why we also recommend tracking waist circumference for a more complete picture.

Are You a Candidate for Bariatric Surgery?

You may qualify for bariatric surgery if you:

Have a BMI of 40 or higher, or
Have a BMI of 35+ with obesity-related health issues
Are 100 pounds or more over your ideal body weight
Have been unable to lose weight through diet and exercise
Are between the ages of 14 and 75

If weight gain is due to a temporary condition (like pregnancy), you may not be eligible.

Why Choose Surgery Over Diets or Injections?

Bariatric surgery is a proven long-term solution. Our experienced team offers:

Gastric Sleeve
Gastric Bypass
Duodenal Switch
Adjustable Gastric Band

These procedures can eliminate or improve diabetes, high blood pressure, sleep apnea, and more — all while helping you regain confidence and mobility.

We do not recommend or prescribe weight-loss injections like semaglutide due to safety concerns.

Start Your Journey Today

Request a Consultation with one of our expert bariatric surgeons in Walnut Creek or Brentwood.

Patient Success Stories

Bariatric Surgery & Obesity Specialists | Weight-Loss Surgery Center clinics in Walnut Creek and Brentwood California

Before Surgery

After Surgery

My Weight-Loss Surgery Success Story

My name is Denise. I started my weight-loss journey in December of 2014 by visiting Dr. Chin. It was ten months of doctors’ appointments, weigh-ins, and medical tests. But I was focused and determined. Finally, my surgery date came. I was sleeved in October 2015, and it was the best decision I have ever made for myself. I was 57 years old at the time. I asked my surgeon, Dr. Chin, if I was too old for the surgery, and he said, “No one is too old to get healthy.” He was so very right. I was 310 pounds at my heaviest, pre-surgery. I was pre-diabetic, and had high blood pressure. My back, knees, and ankles hurt most of the time, and I was always short of breath. Those were just the medical conditions I had because of my weight. I was self-conscious and depressed. I was very unhappy. Surgery was a piece of cake (no pun intended). I was walking on the treadmill within two days. Soon, I was amazed at the transformation I was having, both in my weight loss and with my attitude towards food. As the weight loss kept happening, I was gaining my health back. I am no longer on blood pressure medicine, and I am no longer pre-diabetic. My knees, back, and ankles don’t hurt anymore because I am not carrying so much weight. I can walk and move around without being short of breath. My confidence has returned, and I am so much happier now that I am 100 pounds lighter. I swim a mile five days a week, and walk three to four miles every day, and I enjoy it. There are so many accomplishments that have come from losing weight like shopping in the regular size section, fitting in any chair, crossing my legs, not having to ask for an extension on the airplane, and the list goes on. The only regret I have is not having this surgery sooner. I would like to thank Dr. Chin and all of the staff involved in my life saving/changing surgery.