Weight at a Target Body Fat
The calculation assumes you lose fat while keeping everything else — muscle, bone, water. Because lean mass stays put, the goal weight is simply lean mass divided by one minus the target fat share.
Your numbers
Target weight
70.59kg
Weight to lose
9.41kg
Lean mass
60kg
Formula
Target weight = Weight (kg) × (100 − Body fat) ÷ (100 − Target body fat)
In practice, losing weight quickly takes muscle with it, so the body fat percentage falls short even at the goal weight. Staying under about 1% of body weight per week keeps lean losses small.
What to enter
| Input | Default | Accepted range |
|---|---|---|
| Weight (kg) (kg)The second weight you are comparing against. | 80 | 0 and up |
| Body fat (%)The share of body weight that is fat. | 25 | 0 ~ 70 |
| Target body fat (%)The body fat percentage you are aiming for. | 15 | 0 ~ 70 |
Step by step
Quick reference table
Results when only Weight (kg) (kg) changes and everything else stays put.
| Weight (kg) (kg) | Target weight (kg) | Weight to lose (kg) | Lean mass (kg) |
|---|---|---|---|
| 40 | 35.29 | 4.71 | 30 |
| 60 | 52.94 | 7.06 | 45 |
| 80 | 70.59 | 9.41 | 60 |
| 120 | 105.88 | 14.12 | 90 |
| 160 | 141.18 | 18.82 | 120 |
What each result means
| Result | At default values |
|---|---|
| Target weight (kg)The weight that lands you on the target BMI. | 70.59 |
| Weight to lose (kg)The weight to lose to reach the target. | 9.41 |
| Lean mass (kg)Everything that is not fat — muscle, bone, water. | 60 |
Common mistakes
In practice, losing weight quickly takes muscle with it, so the body fat percentage falls short even at the goal weight. Staying under about 1% of body weight per week keeps lean losses small.
Glossary
- Weight (kg)
- The second weight you are comparing against.
- Body fat
- The share of body weight that is fat.
- Target body fat
- The body fat percentage you are aiming for.
- Target weight
- The weight that lands you on the target BMI.
- Weight to lose
- The weight to lose to reach the target.
- Lean mass
- Everything that is not fat — muscle, bone, water.
Frequently asked questions
Q. How is Weight at a Target Body Fat calculated?
Target weight = Weight (kg) × (100 − Body fat) ÷ (100 − Target body fat) — The calculation assumes you lose fat while keeping everything else — muscle, bone, water. Because lean mass stays put, the goal weight is simply lean mass divided by one minus the target fat share.
Q. Can you walk through an example?
With Weight (kg) 80kg, Body fat 25%, Target body fat 15%, the answer is Target weight 70.59kg.
Q. What do I need to enter?
Enter Weight (kg), Body fat, Target body fat. 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 Weight (kg) (kg) moves the answer to Weight (kg) (kg) 40 → Target weight (kg) 35.29 and Weight (kg) (kg) 160 → Target weight (kg) 141.18. 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?
In practice, losing weight quickly takes muscle with it, so the body fat percentage falls short even at the goal weight. Staying under about 1% of body weight per week keeps lean losses small.
Related calculators
These calculators help you understand health figures; they do not replace diagnosis or prescription. See a clinician if you have symptoms.