The Fitness Weight Estimator converts a chosen BMI range into the corresponding body-weight range for a given height. It can be used to understand how BMI targets translate into kilograms or to compare different planning scenarios. This is not an ideal-weight prescription. The calculation reverses the BMI equation and therefore inherits all of BMI’s limitations, including its inability to account for muscle mass, frame size, body composition, pregnancy, age-specific interpretation, or individual health conditions.
Use centimeters and a consistent standing-height measurement.
Enter the bottom of the BMI interval you want to examine.
The upper value must be equal to or greater than the lower value.
Use the range for mathematical comparison, not as an individualized treatment goal.
Weight (kg) = Target BMI × Height (m)²
The lower and upper weights are calculated separately using the two BMI values. Height is converted from centimeters to meters before squaring.
The main result shows the body weights that correspond mathematically to the selected BMI interval at the entered height.
A suitable body-weight goal depends on more than BMI and may require individualized professional assessment.
Given: Height 175 cm, lower BMI 18.5, upper BMI 24.9.
Calculation: 1.75² = 3.0625. Lower weight = 18.5 × 3.0625 = 56.66 kg. Upper weight = 24.9 × 3.0625 = 76.26 kg.
Result: The estimated range is 56.7–76.3 kg.
No. It only converts a BMI interval into weight values for the entered height.
Yes. Enter any valid lower and upper values, provided the upper value is not smaller.
BMI categories cover broad intervals, and the weight difference grows with height squared.
No. Two people with the same height and weight can have very different body composition.
BMI-based target-weight calculations are not designed to guide pregnancy weight changes. Use pregnancy-specific clinical guidance.