Calculator · Performance Lab
Goal Weight Calculator
Sensible goal weight from a target body-fat percentage — more meaningful than BMI.
Ergebnis
- Estimated target weight
- 78.0kg
- Change
- 7.0kg
- Current fat mass
- 18.7kg
- Lean body mass
- 66.3kg
Assumes lean mass is preserved.
to lose
Explained
What this calculator does for you
A number on the scale says little. 80 kg at 12 % body-fat and 80 kg at 25 % body-fat are two completely different bodies.
This calculator takes the honest route: it asks for your current body-fat and your target, then computes your goal weight — assuming your lean mass is preserved.
That assumption only holds if you keep training hard and eat enough protein. Otherwise part of the difference comes out of muscle — not what you want.
Science
Scientific background
The math is clean: lean mass = weight × (1 − BF%). With constant lean mass, goal weight = lean mass / (1 − target BF%).
Essential body-fat is ~3–5 % in men and ~10–13 % in women. Just above is athletic but already hard. Very low values are not sustainable — research documents hormonal disruption, low libido, sleep problems.
BMI is useless for muscular people — it misclassifies many athletes as overweight. A body-fat-based target is far more meaningful here.
Examples
Practical examples
Male, 85 kg @ 22 % → target 15 %
Lean mass ~66.3 kg → goal weight ~78 kg. Difference ~7 kg, mostly fat — given clean dieting and lifting.
Female, 65 kg @ 30 % → target 22 %
Lean mass ~45.5 kg → goal weight ~58.3 kg. Difference ~6.7 kg.
Avoid these
Common mistakes
- 01Setting a scale-only target without knowing body-fat.
- 02Choosing extremely low body-fat targets that aren't sustainable.
- 03Forgetting the estimate assumes muscle preservation — without training and protein it won't hold.
- 04Treating the number as fixed truth instead of a guideline adjusted over months.
Recommendations
Further recommendations
- 01Set a realistic, health-oriented body-fat target — not stage numbers.
- 02Plan the journey with the diet-duration and pace calculators.
- 03Keep lifting hard and protein high so the 'muscle stays' assumption holds.
- 04Judge across weeks, not days.
FAQ
Frequently asked questions
- How accurate is the estimate?
- It depends entirely on the accuracy of your current body-fat reading. Navy/Bod Pod estimates carry ±3–5 % error — which shifts the goal weight by a few kilos.
- What's a healthy target body-fat?
- Men: 10–15 % is athletic-healthy, 8–10 % is very defined (not comfortable long-term). Women: 18–24 % is healthy-athletic, <16 % approaches stage-lean.
- Why does the calculator assume my muscle mass stays?
- Because it's the best-case scenario — and realistic if you keep lifting and eat ≥2 g/kg protein. Without those, you lose muscle too.
- Should I set my goal via BMI or body-fat?
- For trained people: body-fat. BMI is for epidemiological statements, not individual training goals.
More tools
Related tools
Body Fat Calculator
Estimate your body-fat percentage with the U.S. Navy circumference method — fast, no device, with clear classification.
BMI Calculator
Body-Mass-Index by WHO standard. A quick orientation — with an honest read on its limits.
Cut Calculator
Target calories and pace for a clean, muscle-preserving cut.
Diet Duration Calculator
How long your diet takes at your chosen pace — estimated realistically.
Pace Calculator
Translates your desired pace into the required daily calorie delta — and rates it honestly.
Calorie Calculator
Calculate your basal metabolic rate, total daily energy expenditure and target calories — precisely, via Mifflin-St Jeor.
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