SnapMyGym
Quick body-mass-index estimate with healthy-range markers — a baseline, not a verdict. Free BMI calculator, no signup.
BMI (body mass index) is weight divided by height squared — a fast population-level screen for weight categories. It's a reasonable baseline, but it cannot tell muscle from fat, which is exactly where lifters need a second opinion.
BMI was built to describe populations, not individuals. Anyone carrying meaningful muscle — which includes most consistent lifters — reads as overweight at a body-fat level a physician would call healthy, because the formula sees only mass, never composition.
Use BMI as one directional data point alongside body-fat percentage and waist measurement. If BMI says overweight but the tape and the mirror say lean, trust the tape. If all three agree, they're probably right.
No — it systematically over-classifies muscular people as overweight or obese. Pair it with a body-fat estimate (the Navy tape method works well) before drawing any conclusion from it.
18.5–24.9 is the standard normal band, 25–29.9 counts as overweight, and 30+ as obese. Those cutoffs predict health risk reasonably well at the population level and poorly for muscular, very short, or very tall individuals.
Body-fat percentage plus waist circumference tracks health and physique change far better for individuals. BMI remains useful as a quick screen and for watching your own long-term trend.
Want the number to actually go up? Snap My Gym builds percentage-based programs around your lifts and tracks them automatically. More evidence-first training articles on the blog.