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Know your body

Target body fat calculator

“I want to be 12%” is a clearer goal than “I want to lose 10 kg”. This calculator converts a body-fat target into a scale weight, assuming you hold on to your muscle, and gives a realistic range for when some lean mass goes too.

Your numbers

Sex
kg
cm
Body fat
%

From a DEXA scan, calipers, a smart scale or the tape method.

12%

Your goal weight appears here

Enter your weight and a current body-fat estimate, then drag the target.

How it’s calculated

The formula

Lean mass = weight × (1 − current BF). Goal weight = lean mass ÷ (1 − target BF). This assumes all weight lost is fat.

The realistic range

Even a well-run cut loses some lean tissue — a quarter of total weight lost is common without resistance training, far less with it. We show a second figure assuming about 20% of the loss is lean, which is where most people actually land.

Full sources and limitations are on the methodology page. Estimates are for healthy adults and are not medical advice.

Questions

How lean should I get?

For most men, 10–15% looks lean and athletic and is sustainable. For most women, 18–24%. Going lower is possible but harder to maintain and can affect energy, sleep and hormones.

How long will it take?

At 0.5–1% of bodyweight per week, most people lose 2–4 kg a month. Use the cutting calculator for a week-by-week estimate.