Our online body fat calculator includes 5 methods — from the quick Navy circumference method to the precise 7-site caliper skinfold. Choose based on what measurements you have.
The most popular online body fat calculator. Uses neck and waist (men) or neck, waist, and hip (women) circumferences with a logarithmic formula. No special equipment needed — just a flexible tape measure.
Our army body fat calculator, military body fat calculator, and USMC body fat calculator use the same DoD tape formula but apply branch-specific max body fat standards. Check if you'd pass Army, Navy, and USMC simultaneously.
Our caliper body fat calculator and body fat calculator caliper uses the 3-site Jackson-Pollock formula. Men: chest + abdominal + thigh. Women: tricep + suprailiac + thigh. Requires body fat calipers.
Our skinfold body fat calculator and 7-site body fat calculator is the most accurate non-lab method. Measures 7 skinfold sites using the Jackson-Pollock formula. Used by professional trainers and sports scientists.
Our free body fat calculator is more complete than calculator.net, OmniCalculator, and FatCalc — because it offers 5 calculation methods in one tool: the US Navy body fat calculator (Hodgdon & Beckett 1984), the US Army body fat calculator / USMC body fat calculator (DoD formula), the 3-site caliper body fat calculator (Jackson-Pollock), the 7-site skinfold body fat calculator, and the BMI body fat calculator (Deurenberg formula). Results include body fat percentage, ACE category classification, lean body mass, fat mass, and a comparison against Army, Navy, and Marine Corps body fat standards.
The army body fat calculator and body fat calculator army uses the DoD tape test formula — the same as the Navy method but with Army-specific maximum limits. AR 600-9 (Army Regulation) sets the following body fat limits:
| Age Group | Men Max BF% | Women Max BF% | Notes |
|---|---|---|---|
| 17–20 years | 20% | 30% | Strictest age group |
| 21–27 years | 22% | 32% | Most recruits |
| 28–39 years | 24% | 34% | Mid-career soldiers |
| 40+ years | 26% | 36% | Senior soldiers |
The US navy body fat calculator formula men uses: %BF = 86.010 × log₁₀(waist − neck) − 70.041 × log₁₀(height) + 36.76. All measurements in cm. For the us navy body fat calculator formula for men in inches: %BF = 86.010 × log₁₀(waist − neck) − 70.041 × log₁₀(height) + 36.76 (same formula, just measurements in inches). Women's formula adds hip circumference: %BF = 163.205 × log₁₀(waist + hip − neck) − 97.684 × log₁₀(height) − 78.387. This Hodgdon-Beckett formula is also used by the USMC body fat calculator — the difference between branches is only the maximum allowed percentage, not the formula itself.
The caliper body fat calculator, body fat calculator caliper, and skinfold body fat calculator use the Jackson-Pollock formula with body fat calipers. The 3-site formula for men uses chest + abdominal + thigh skinfolds: Density = 1.10938 − 0.0008267×(sum) + 0.0000016×(sum²) − 0.0002574×age. Body fat % = (495/density) − 450. Women use tricep + suprailiac + thigh. The 7-site formula (our most accurate most accurate body fat calculator option) uses 7 sites for ±2.5–3.5% accuracy — comparable to hydrostatic weighing.
The USMC body fat calculator applies the strictest body fat limits of all US military branches. USMC maximum body fat: Men 18% (all ages), Women 26% (all ages). This compares to Army's 20–26% (men) and 30–36% (women) depending on age. The Marine Corps uses the same tape measurement formula as the Army and Navy but maintains a single strict limit regardless of age. Our military body fat calculator checks your result against all three branches simultaneously.
Measuring tips for accurate results: Always measure on bare skin, not over clothing. Relax muscles — don't flex. Measure to the nearest 0.5cm for best accuracy. The Navy method slightly underestimates body fat in very muscular people (because large neck circumference from muscle reduces the formula result). For muscular athletes, use the caliper method instead of the tape-based navy body fat calculator.
Body fat vs BMI: A person with 25% body fat and high muscle mass may have a "normal" BMI while being metabolically healthy. A sedentary person at the same BMI might have 30% body fat — the difference matters clinically. Our BMI body fat calculator mode estimates fat from BMI using the Deurenberg formula (adds age and gender adjustments), giving a body fat estimate when no other measurements are available. For the most accurate result without lab equipment, use our most accurate body fat calculator — the 7-site caliper skinfold method.
Questions covering Navy and Army formulas, USMC standards, caliper accuracy, healthy body fat ranges, and BMI vs body fat percentage.
The US Navy body fat calculator formula (Hodgdon & Beckett, 1984): Men: %BF = 86.010×log₁₀(waist − neck) − 70.041×log₁₀(height) + 36.76. Women: %BF = 163.205×log₁₀(waist + hip − neck) − 97.684×log₁₀(height) − 78.387. All measurements in cm. Men need neck and waist circumferences. Women need neck, waist, and hip. The us navy body fat calculator formula men omits hip because men store less fat in the hip area. Our navy body fat calculator applies these exact formulas — accuracy is ±3–4% vs DEXA scan when measurements are taken correctly.
Our army body fat calculator and USMC body fat calculator check against these standards: US Army (AR 600-9) men: 20% (17–20 yrs), 22% (21–27), 24% (28–39), 26% (40+). Army women: 30%, 32%, 34%, 36% by same age groups. USMC (strictest): men 18% all ages, women 26% all ages. US Navy: men 22% (17–21), 23% (22–29), 23% (30–39), 26% (40+). Women Navy: 33%, 34%, 35%, 36% by age group. Our military body fat calculator checks all three branches simultaneously and shows which ones you pass or fail.
Our caliper body fat calculator, body fat calculator caliper, and skinfold body fat calculator accuracy varies by method: 3-site Jackson-Pollock: ±3–4% (when done correctly). 7-site Jackson-Pollock: ±2.5–3.5% (most accurate home method). Durnin-Womersley 4-site (women): ±3–4%. Accuracy requires a trained tester, correct site location, consistent measurement technique, and quality calipers. Self-measurement with calipers is less reliable than having a trained fitness professional measure. The Navy tape method (±3–4%) is often equally accurate for most people and much easier to self-administer.
Healthy body fat ranges (ACE classification): Men — Essential fat: 2–5%, Athletic: 6–13%, Fitness: 14–17%, Average: 18–24%, Obese: 25%+. Women — Essential fat: 10–13%, Athletic: 14–20%, Fitness: 21–24%, Average: 25–31%, Obese: 32%+. Women have higher essential fat due to hormonal and reproductive biology — this is why the body fat calculator for women ranges are higher than the body fat calculator for men. Most health authorities consider the "fitness" range the ideal target for non-athletes. Our percent body fat calculator shows exactly which category you fall into.
BMI only uses height and weight — it cannot distinguish muscle from fat. A 200 lb bodybuilder and a 200 lb sedentary person have identical BMIs, but very different body fat percentages. Our BMI body fat calculator uses the Deurenberg formula to estimate body fat from BMI: %BF = (1.20 × BMI) + (0.23 × age) − (10.8 × sex) − 5.4. This estimates ±5–8% accuracy — less accurate than the navy body fat calculator or caliper body fat calculator, but useful when no tape or calipers are available. For most people, measuring with tape (Navy method) gives a much better body fat estimate than BMI alone.
An AI body fat calculator typically refers to photo-based body composition analysis using machine learning — you upload a photo and AI estimates body fat percentage from visual cues like muscle definition and body shape. Accuracy varies widely (±5–10%) and depends on lighting, clothing, and algorithm quality. Our online body fat calculator uses clinically validated mathematical formulas (Navy, Army, Jackson-Pollock) that are more reliable than most AI photo methods. For a true body fat measurement, DEXA scan (dual-energy X-ray absorptiometry) is the gold standard at ±1–2% accuracy, followed by hydrostatic weighing, and then our 7-site skinfold calculator at ±2.5–3.5%.