Does this calculator assume no muscle loss?

Yes. It assumes lean mass is maintained. That makes the target easy to calculate, but real results may differ.

Can I use it for muscle gain goals?

Yes, but it is more useful for fat-loss targets. For lean bulk goals, you need to consider how much lean mass and fat mass may both change.

What if my body-fat estimate is wrong?

Then the target weight will also be wrong. Use a realistic estimate and update it over time.

Should I aim for very low body fat?

Not necessarily. Very low body fat can be hard to maintain and may not be appropriate for every sport, sex, age, or health context.

Why does target weight sometimes look lower than expected?

Because lowering body-fat percentage while keeping lean mass constant often requires reducing fat mass significantly.

Sports & Fitness

Target Body Fat Weight Calculator

Estimate your target body weight for a chosen body-fat percentage while assuming lean mass is maintained, with fat mass and scale-change outputs.

What target body-fat weight means

This calculator estimates the body weight that would correspond to a chosen target body-fat percentage if lean mass stayed the same. That assumption is important. It makes the math useful for planning, but real body recomposition can include changes in muscle, water, glycogen, and fat-free mass.

Formula

Lean mass = current weight × (1 − current body fat %) Target weight = lean mass ÷ (1 − target body fat %)

This is a body-composition planning formula, not a medical prescription. It pairs naturally with lean body mass and FFMI calculations because all three depend on fat mass versus fat-free mass.

How to use it for realistic goals

If the calculator says you need to lose 10 kg to reach a target body-fat percentage, that does not mean the goal should happen quickly. Strength athletes often want to preserve lean mass while reducing fat mass, so the rate of loss, protein intake, training, and recovery matter.

Why the assumption matters

Research on body-composition changes during weight loss shows that fat mass and lean mass can both change depending on diet and training. A review of body-composition changes in weight loss strategies gives useful context for why a calculator should not assume every kilogram lost is pure fat.

Frequently asked questions

Yes. It assumes lean mass is maintained. That makes the target easy to calculate, but real results may differ.
Yes, but it is more useful for fat-loss targets. For lean bulk goals, you need to consider how much lean mass and fat mass may both change.
Then the target weight will also be wrong. Use a realistic estimate and update it over time.
Not necessarily. Very low body fat can be hard to maintain and may not be appropriate for every sport, sex, age, or health context.
Because lowering body-fat percentage while keeping lean mass constant often requires reducing fat mass significantly.