Body Fat Calculator
Estimate your body-fat percentage with just a tape measure: height, neck and waist (plus hips for women). This free calculator uses the US Navy circumference method — accurate to within a few percent of lab testing — and shows your fat mass and lean mass if you add your weight.
No calipers, no scan, no signup. Measure consistently and re-check every few weeks — the trend over time is the number that tells you whether your training and nutrition are working.
| Body fat (male) | Classification |
|---|---|
| 2 – 5% | Essential fat |
| 6 – 13% | Athletic |
| 14 – 17% | Fit |
| 18 – 24% | Average |
| 25%+ | High |
Tape estimates are typically within ±3–4% of lab methods. Measure at the same time of day, relaxed, and track the trend rather than any single reading.
Why track body fat instead of just weight
Scale weight lumps together fat, muscle, water and everything else — so it can stall or rise even while your body composition improves. Body-fat percentage splits the number in two: fat mass and lean mass. A recomposition phase where you gain muscle and lose fat shows up clearly here while the scale shows nothing.
The combination that moves this number the right way is no secret: strength training a few days a week to build or protect lean mass, and calories matched to your goal. Get your calorie targets from the TDEE & macro calculator and a training plan from the free routines — then re-measure monthly.
Train the lean-mass side of the equation
SSS Workout Assistant builds a free weekly strength routine around your goal and equipment, tracks every set, and keeps you consistent — the part that actually changes this number.
Start freeFrequently asked questions
How accurate is the tape-measure body-fat method?
The US Navy circumference method typically lands within ±3–4% of laboratory methods for most people. Its real strength is consistency: measured the same way at the same time of day, it tracks your trend reliably, which matters far more than nailing one exact number.
What is a healthy body-fat percentage?
Commonly used fitness ranges put 14–24% as fit-to-average for men and 21–31% for women, with athletes lower and essential fat around 2–5% (men) and 10–13% (women). Where you want to sit within the healthy span is personal — sustainable beats extreme.
How do I measure correctly for this calculator?
Use a flexible tape, snug but not compressing the skin. Neck: just below the larynx, sloping slightly down at the front. Waist: men at navel height, women at the narrowest point. Hips (women): at the widest point. Measure relaxed — don't suck in.
Body fat or BMI — which should I track?
Body-fat percentage is the better individual metric because it separates fat from lean mass, which BMI cannot do. BMI remains a quick cross-check. Tracking both monthly, plus waist measurement and gym performance, gives a fuller picture than any single number.
How fast can I realistically lower my body-fat percentage?
A sustainable fat-loss pace is roughly 0.5–1% of body-fat percentage per month for most people — driven by a modest calorie deficit while strength training to hold onto lean mass. Faster drops usually cost muscle, which lowers the lean side of the same ratio.
This calculator is a general fitness tool, not medical advice or a clinical body-composition assessment.