BMI Goal Weight Calculator

Body Mass Index (BMI) is weight divided by height squared, a single number used to sort people into broad weight categories. Most calculators run it forward: you enter your weight and get a score. This one runs it backward. You give it a target score and it tells you the weight that produces it, which is the more useful direction if you are trying to set a goal rather than grade yourself.

Formula: Goal Weight = Target BMI × Height² (in meters)

In imperial units: Goal Weight (lbs) = Target BMI × Height² (in inches) ÷ 703

That 703 is just the unit conversion folded into a constant, nothing more.

Standard BMI categories, per the World Health Organization (WHO):

• Underweight: BMI < 18.5
• Normal weight: BMI 18.5–24.9
• Overweight: BMI 25.0–29.9
• Obese Class I: BMI 30.0–34.9
• Obese Class II: BMI 35.0–39.9
• Obese Class III: BMI ≥ 40.0

Worked example: Person is 5'8" (68 inches / 1.727 m) and wants to reach a BMI of 22 (mid-normal range).

Metric: Goal Weight = 22 × 1.727² = 22 × 2.982 = 65.6 kg Imperial: Goal Weight = 22 × 68² ÷ 703 = 22 × 4,624 ÷ 703 = 144.6 lbs

For a range (BMI 18.5 to 24.9):

• Lower bound: 18.5 × 2.982 = 55.2 kg (121.7 lbs)
• Upper bound: 24.9 × 2.982 = 74.3 kg (163.7 lbs)

This person’s healthy weight range is 122–164 lbs.

Important limitations: BMI is a screening tool, not a diagnostic one. It doesn’t account for muscle mass, bone density, body fat distribution, age, or ethnicity. Athletes often have “overweight” BMIs despite excellent health. Always use BMI alongside other metrics (waist circumference, body fat %, blood work) when setting health goals.