Body Fat Percentage Calculator
Estimate your body-fat percentage with just a measuring tape, using the US Navy method — in centimetres or inches.
Enter your details to see your result.
How the body fat calculator works
The US Navy method (Hodgdon & Beckett) estimates body fat from your height and a few tape measurements. It is the method the US military uses, and in studies it lands within about 3–4 percentage points of lab methods like DEXA.
BF% = 495 ÷ (1.0324 − 0.19077 × log₁₀(waist − neck) + 0.15456 × log₁₀(height)) − 450BF% = 495 ÷ (1.29579 − 0.35004 × log₁₀(waist + hip − neck) + 0.22100 × log₁₀(height)) − 450All measurements are in centimetres (inches are converted for you). If you enter your weight, we also split it into fat mass and lean mass.
How to measure
- Neck: just below the Adam’s apple, tape sloping slightly down at the front.
- Waist: men at the navel; women at the narrowest point. Breathe out normally and don’t suck in.
- Hips (women): around the widest part of the buttocks.
- Keep the tape snug but not pressing into the skin, and measure twice.
Reading your result
| Category | Men | Women |
|---|---|---|
| Essential fat | 2–5% | 10–13% |
| Athletic | 6–13% | 14–20% |
| Fit | 14–17% | 21–24% |
| Average | 18–24% | 25–31% |
| High | 25% + | 32% + |
Categories from the American Council on Exercise (ACE).
Tips & limitations
- Measure at the same time of day — ideally in the morning before food — so changes reflect fat, not a big meal.
- Track the trend over 4–8 weeks rather than single readings.
- Waist going down while weight stays the same usually means you’re losing fat and gaining muscle.
- Choose inches on the tape-unit switch if your tape is in inches — we convert it for you.
Frequently asked questions
How accurate is the US Navy body fat method?
For most people it is within about 3–4 percentage points of DEXA scans. It is less accurate for very lean or very muscular people, but it is excellent for tracking change over time when you measure the same way.
Can I measure in inches?
Yes. Switch the tape unit to inches and enter your measurements as they are; the calculator converts them to centimetres before applying the formula.
What is a good body fat percentage?
For general health, roughly 14–24% for men and 21–31% for women is fine. Athletes are usually lower: around 6–13% for men and 14–20% for women.
Why do women need a hip measurement?
Women naturally store more fat around the hips and thighs, so the female formula includes hips to give a more accurate estimate.
More free calculators
BMI Calculator
Body Mass Index with Asian-Indian cut-offs, plus your healthy and ideal weight range.
- BMI score & category
- Healthy weight range
- Ideal body weight
Macro Calculator
Daily protein, carbs and fat in grams for fat loss, maintenance or muscle gain.
- Calories for your goal
- Protein, carbs & fat
- Per-meal breakdown
Calorie Calculator
Your BMR, daily calorie burn (TDEE) and targets for fat loss or lean gain.
- BMR & TDEE
- Fat-loss calories
- Lean-gain calories
These calculators give estimates for general fitness guidance only and aren’t medical advice. Speak to a doctor before making major diet or training changes, especially if you are pregnant, under 18 or have a medical condition.