Understand your BMI. Unlock your next move.

Body Mass Index (BMI) is a simple screening tool that compares your weight to your height. It helps estimate whether you’re underweight, at a healthy weight, overweight, or living with obesity.

While BMI doesn’t measure body composition, muscle mass, or overall metabolic health, it’s still widely used because it offers a quick, consistent way to identify possible health risks related to weight.

Your BMI can help clinicians determine whether GLP-1 treatments may be appropriate for you. A qualifying BMI for weight-loss injections is typically 30 or higher, or 27 or higher with at least one weight-related medical condition (such as high blood pressure or high cholesterol).

BMI is calculated by dividing your weight in kilograms by your height in meters squared.

With our BMI calculator, you don’t need to do any math.The calculator handles it automatically.

BMI Formula

BMI = weight (kg) ÷ [height (m)]²

BMI Categories

• Underweight: Less than 18.5
• Normal weight: 18.5 to 24.9
• Overweight: 25 to 29.9
• Class 1 obesity: 30 to 34.9
• Class 2 obesity: 35 to 39.9
• Class 3 obesity: 40 or higher

These categories apply to adults 20+ only. They do not account for children, teenagers, pregnant individuals, or individuals with certain medical exceptions.

Your BMI result helps you understand your weight category and potential health considerations:

• Underweight (less than 18.5): May indicate nutritional deficiencies or other underlying conditions.
• Normal weight (18.5 to 24.9): Typically associated with a lower risk of weight-related health issues.
• Overweight (25 to 29.9): May increase the risk of developing conditions like high blood pressure or diabetes.
• Obesity (30 to 40+): Often linked to a higher risk of chronic diseases and may qualify you for medical weight-loss treatment.

If your BMI is 30 or higher, consider whether medical weight-loss support is recommended for you.

BMI is helpful, but it doesn’t account for important factors such as:

• Body fat percentage
• Muscle mass
• Fat distribution
• Metabolic health
• Genetic factors
• Lifestyle, activity level, or diet
• Underlying medical conditions

This is why clinicians consider BMI alongside other measurements when evaluating health and treatment options.

Weight-loss medications — including GLP-1 treatments — can support people who haven’t seen results through lifestyle changes alone.

You may want to consider medication if:

• You have a BMI of 30 or higher
• You have a BMI of 27 or higher with a weight-related health condition
• You’ve struggled to lose weight with diet and exercise alone
• Your weight is affecting your daily life, mobility, or confidence
• You want medical guidance to help manage appetite and cravings

Obesity is a chronic medical condition, and medication can be a safe, evidence-based way to get meaningful support.

If you’d like to learn more, you can connect with a licensed Sunlight provider from the comfort of your home.

Qualifying BMI for Weight Loss Medication

To qualify for weight-loss treatments, you generally need an elevated BMI, but the threshold can depend on the medication and your health history.

You may qualify with a BMI of 27+ if you have conditions such as:

• High blood pressure
• High cholesterol
• Prediabetes or type 2 diabetes
• Sleep apnea
• Polycystic ovary syndrome (PCOS)
• Fatty liver disease (NAFLD)
• Joint pain related to weight

Your clinician will review your intake form and determine the safest, most appropriate option for you.

Next Steps for Medical Weight Loss

If your BMI indicates that you’re in the overweight or obese range, it may be time to talk with a medical provider about treatment options.

Sunlight connects you with licensed clinicians who specialize in GLP-1 weight-loss care. If you’re ready for support, you can take a short eligibility quiz to see if treatment may be right for you.