The GLP-1 Dick Calculator

Interactive tool • Based on urological & endocrine data • Updated March 2026

How We Calculate These Estimates

Visible length gain: Based on the urological estimate of approximately 1 inch of visible penile length gained per 30–50 lbs of fat loss, adjusted for body type (men who carry fat predominantly in the belly/suprapubic region gain more per pound than men with even fat distribution). The estimate uses a conservative-to-moderate model: 1 inch per 35 lbs for belly-dominant fat carriers, 1 inch per 45 lbs for all-over carriers, and 1 inch per 55 lbs for lower-body carriers.

Functional length gain: Estimated at 120–130% of visible length gain. The suprapubic fat pad acts as a physical cushion during intercourse, and its reduction improves penetration depth by slightly more than the visible length change.

Testosterone improvement: Based on ENDO 2025 data showing average testosterone increases of 120–180 ng/dL in men achieving ≥10% body weight loss on GLP-1 therapy. Scaled proportionally to weight loss percentage, with a floor of 50 ng/dL (minimum expected improvement) and ceiling of 250 ng/dL (maximum typical improvement without TRT). Starting testosterone is estimated from BMI using published regression models.

ED improvement probability: Based on a composite of published data on weight loss, testosterone restoration, and vascular improvement effects on erectile function. The model incorporates weight loss percentage, estimated testosterone change, and age-adjusted baseline ED prevalence. This is a probability estimate, not a guarantee.

For the full science behind these calculations, read How Much Bigger Does Your Dick Get When You Lose Weight? and our comprehensive penis size and weight loss guide.