Target Weight for a BMI
Multiply the target BMI by height in metres squared to get the weight that produces it. The gap from your current weight is what you need to lose or gain.
Your numbers
Target weight
66.5kg
Difference
13.5kg
BMI
27.7
Formula
Target weight = Target BMI × (Height (cm) ÷ 100)²
Losing more than about 4% of body weight a month costs muscle — give the goal enough time.
What to enter
| Input | Default | Accepted range |
|---|---|---|
| Height (cm)Height in centimetres; converted to metres inside the formula. | 170 | 100 ~ 250 |
| Weight (kg)The second weight you are comparing against. | 80 | 10 ~ 300 |
| Target BMIThe BMI figure you are aiming at. | 23 | 15 ~ 40 |
Step by step
Quick reference table
Results when only Height (cm) changes and everything else stays put.
| Height (cm) | Target weight (kg) | Difference (kg) | BMI |
|---|---|---|---|
| 100 | 23 | 57 | 80 |
| 128 | 37.7 | 42.3 | 48.8 |
| 170 | 66.5 | 13.5 | 27.7 |
| 250 | 143.8 | -63.7 | 12.8 |
What each result means
| Result | At default values |
|---|---|
| Target weight (kg)The weight that lands you on the target BMI. | 66.5 |
| Difference (kg)The gap between two values — a quantity, not a rate. | 13.5 |
| BMIA build index from height and weight alone; it cannot tell muscle from fat. | 27.7 |
Common mistakes
Losing more than about 4% of body weight a month costs muscle — give the goal enough time.
Glossary
- Height (cm)
- Height in centimetres; converted to metres inside the formula.
- Weight (kg)
- The second weight you are comparing against.
- Target BMI
- The BMI figure you are aiming at.
- Target weight
- The weight that lands you on the target BMI.
- Difference
- The gap between two values — a quantity, not a rate.
- BMI
- A build index from height and weight alone; it cannot tell muscle from fat.
Frequently asked questions
Q. How is Target Weight for a BMI calculated?
Target weight = Target BMI × (Height (cm) ÷ 100)² — Multiply the target BMI by height in metres squared to get the weight that produces it. The gap from your current weight is what you need to lose or gain.
Q. Can you walk through an example?
With Height (cm) 170, Weight (kg) 80, Target BMI 23, the answer is Target weight 66.5kg.
Q. What do I need to enter?
Enter Height (cm), Weight (kg), Target BMI. The result recalculates as you type, and an empty box counts as zero.
Q. How much does the answer move if I change a number?
Changing only Height (cm) moves the answer to Height (cm) 100 → Target weight (kg) 23 and Height (cm) 250 → Target weight (kg) 143.8. The table below lays out five steps.
Q. How are the numbers rounded?
Money is shown to the nearest whole unit, percentages to one decimal place and everything else to two. What you see is rounded; the calculation itself carries the unrounded value forward.
Q. Anything to watch out for?
Losing more than about 4% of body weight a month costs muscle — give the goal enough time.
Related calculators
These calculators help you understand health figures; they do not replace diagnosis or prescription. See a clinician if you have symptoms.