How to measure (it matters more than the formula)
- Use a soft, non-stretch tape. Measure on bare skin, first thing in the morning, before eating.
- Neck: just below the larynx (Adam's apple), with the tape sloping slightly down towards the front.
- Waist: men at the belly button; women at the narrowest point. Stand relaxed and measure after a normal breath out — don't suck in.
- Hips (women): around the widest part of the buttocks, feet together.
- Take each measurement twice and use the average. The tape should sit snug without pressing into the skin.
A 1 cm error at the waist changes the result by roughly half a percentage point, so measure the same way every time.
Body fat percentage chart
| Category | Men | Women |
|---|---|---|
| Essential fat | 2–5% | 10–13% |
| Athletic | 6–13% | 14–20% |
| Fitness | 14–17% | 21–24% |
| Average | 18–24% | 25–31% |
| Above average | 25% + | 32% + |
Women naturally carry more essential fat for hormonal and reproductive health, which is why their ranges are higher. Very low body fat isn't a health goal — for women in particular, dropping toward essential levels can disrupt periods and bone health.
Body fat in Indians and South Asians
Studies in Singapore and India have found that South Asians often carry more body fat at the same BMI than Europeans — sometimes 3–5 percentage points more — with more of it stored around the abdomen. This “thin-fat” pattern is one reason Indian guidelines use lower BMI and waist cut-offs.
The Navy formula was developed largely on U.S. service members, so it may under-read body fat slightly for South Asians. Treat your result as a trend tracker and pair it with your waist-to-height ratio: keeping your waist under half your height is a simple, well-supported target. Compare with the BMI calculator, which shows Indian cut-offs.
How accurate are body fat methods?
| Method | Typical error | Notes |
|---|---|---|
| DEXA scan | ≈ 1–2% | Reference standard in most clinics; costs money |
| Tape measure (Navy) | ≈ 3–4% | Free, repeatable, good for tracking trends |
| Skinfold calipers | ≈ 3–5% | Depends heavily on the tester's skill |
| Smart scales (BIA) | ≈ 4–8% | Shifts with hydration, meals and time of day |
| Mirror / photos | — | Underrated for tracking change over months |
How to lower your body fat
Body fat comes down with a moderate calorie deficit, enough protein and strength training — the training is what makes sure the weight you lose is fat rather than muscle. Spot-reducing belly fat with crunches doesn't work; overall fat loss does.
Start with the calorie deficit calculator and read how to lose belly fat.
Worked example: Arjun and Meera
Arjun: 175 cm, 80 kg, neck 38 cm, waist 90 cm. His estimate is about 20.7% body fat — the “average” band — with roughly 16.6 kg of fat and 63.4 kg of lean mass. His waist-to-height ratio is 0.51, just over the 0.5 rule of thumb.
Meera: 160 cm, 62 kg, neck 33 cm, waist 78 cm, hips 98 cm. Her estimate is about 31.3%, the top of the average band, with a waist-to-height ratio of 0.49.
Both would see more benefit from tracking these numbers monthly than from chasing a specific percentage.
How this calculator works
We use the U.S. Navy circumference equations (Hodgdon & Beckett, 1984) in metric form. Men: 495 ÷ (1.0324 − 0.19077 × log₁₀(waist − neck) + 0.15456 × log₁₀(height)) − 450. Women: 495 ÷ (1.29579 − 0.35004 × log₁₀(waist + hip − neck) + 0.22100 × log₁₀(height)) − 450. All measurements are in centimetres.
Fat mass = weight × body fat %; lean mass is the rest. Categories follow ACE reference ranges. Designed for adults; not valid during pregnancy and less reliable at very high or very low body fat.
Sources
- Peterson DD. History of the U.S. Navy Body Composition program. Mil Med, 2015.
- Shake CL, et al. Predicting percent body fat from circumference measurements. Mil Med, 1993.
- Deurenberg-Yap M, et al. The paradox of low body mass index and high body fat percentage among Chinese, Malays and Indians in Singapore. Int J Obes, 2000.
- Ashwell M, et al. Waist-to-height ratio is a better screening tool than waist circumference and BMI for adult cardiometabolic risk factors: systematic review and meta-analysis. Obes Rev, 2012.
Frequently asked questions
Straight answers about this calculator. Educational only — not medical advice.
For most adult men, roughly 10–20%, and for women roughly 20–30%, is a healthy range. Athletes often sit lower; older adults often sit a little higher.
It's usually within about 3–4 percentage points of a DEXA scan for most people. That's good enough to track progress if you measure carefully and consistently.
Women store more fat around the hips and thighs, so the women's equation uses waist plus hips minus neck to capture it.
Not usually. Smart scales use bioelectrical impedance, which swings with hydration, meals and time of day. A tape is cheaper and often more consistent.
Yes. This is common in South Asians and in people who don't do strength training. A body fat estimate or waist measurement can reveal it when BMI doesn't.
Every 2–4 weeks is plenty. Weekly changes are smaller than the measurement error.
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This calculator provides an estimate and isn't a substitute for individualised medical or dietary advice. Read our medical disclaimer and editorial policy.