BMI Comparison: Current vs Goal Weight
See where you start, where you finish, and where you cross each BMI threshold on the way.
What BMI tells you — and what it doesn't
Body Mass Index is a weight-for-height ratio designed by a Belgian statistician in the 1830s as a population-level estimate of relative fatness. It wasn't designed to diagnose individuals and it does a poor job of that for athletes, older adults, and people with unusual lean-to-fat ratios. For typical adults in the middle of the population, BMI correlates with body fat tightly enough to be useful as a screening tool.
The categories
Under 18.5 is classified as underweight. 18.5 to 24.9 is the "normal" range. 25 to 29.9 is overweight. 30 to 34.9 is Class I obese, 35 to 39.9 is Class II, and 40+ is Class III. These thresholds are where all-cause mortality curves bend noticeably in large population studies — they are not arbitrary.
Where BMI misleads
A 5'10" former athlete at 200 pounds with 15% body fat has a BMI of 28.7 — technically overweight. A sedentary 5'10" person at 170 pounds with 30% body fat has a BMI of 24.4 — technically normal. In every health metric that matters, the first person is better off. BMI is useful but not sufficient; pair it with the waist-to-height ratio to correct for this.
Crossing the thresholds
For a 5'10" person, BMI 30 is 209 pounds, BMI 25 is 174 pounds, and BMI 18.5 is 129 pounds. The calculator above shows you exactly where each threshold lands for your height so you can mark milestones along the way. Crossing from obese into overweight has the largest short-term health payoff — blood pressure, lipid panels, and sleep quality all respond disproportionately to the first 5–10% of weight lost.
Why "normal BMI" isn't always the goal
The lowest-mortality BMI in several large epidemiological studies is 23–25 for under-50s and 25–27 for over-65s. For older adults, slightly higher BMI is protective because it correlates with preserved muscle mass and reserve during illness. Younger adults benefit from the lower end of normal, but chasing BMI 20 without monitoring body composition usually means losing muscle.
BMI during a cut
Use BMI as a milestone marker, not a daily metric. Bodyfat (see the body fat goal calculator) and waist measurement move more accurately. BMI can show the same number across several pounds of water fluctuation, which is distracting. Check it every four weeks at most.
BMI and risk stratification
Type 2 diabetes risk climbs noticeably at BMI 27 for most ethnic groups and lower (around 23) for South and East Asian populations. Cardiovascular risk starts climbing at BMI 25. Cancer risk has a weaker BMI association but correlates more strongly with abdominal fat — again, pair with waist-to-height.
Using the chart
The orange curve shows BMI dropping as weight drops across your goal range, with dashed reference lines at BMI 25 and 30. If the whole curve is above 30, the first 10% of weight loss is the most valuable health intervention of your adult life. If the curve starts in the overweight range and crosses into normal, you're doing cosmetic work with a moderate health payoff.
Disclaimer: This tool provides estimates for educational purposes and is not medical or nutritional advice. Individual results vary. Always consult a licensed physician or registered dietitian before starting a new diet, fasting protocol, or exercise program — especially if you have a medical condition, are pregnant or nursing, or are under 18.