Estimate your body fat percentage using circumference measurements. Discover your lean mass, fat mass, and ideal body fat range.
Measure just below the larynx (Adam's apple)
Measure at belly button level, relaxed stomach
Essential Fat: 2-5%
Athletes: 6-13%
Fitness: 14-17%
Average: 18-24%
Obese: 25%+
Body fat percentage represents the proportion of your total body weight that is fat versus lean mass (muscle, bone, organs, water). Unlike BMI which only considers height and weight, body fat percentage gives true insight into body composition and health.
Two people can weigh the same but have vastly different body compositions. A 200 lb bodybuilder at 10% body fat has 180 lbs lean mass, 20 lbs fat. A 200 lb sedentary person at 30% body fat has 140 lbs lean mass, 60 lbs fat. Same weight, completely different health and appearance.
Body fat percentage correlates with:
This calculator uses the US Navy Circumference Method, developed by the military for field body composition assessment. It's based on the principle that body fat distribution affects circumference measurements—higher body fat increases waist relative to height and neck.
For Men:
Body Fat % = 86.010 × log10(waist - neck) - 70.041 × log10(height) + 36.76
For Women:
Body Fat % = 163.205 × log10(waist + hip - neck) - 97.684 × log10(height) - 78.387
Accuracy: ±3-4% compared to DEXA scan (gold standard). More accurate than BMI or simple weight measurements.
Limitations:
Despite limitations, Navy method provides good estimates when measurements are taken carefully and consistently. Use same method for tracking changes over time.
Measure just below the larynx (Adam's apple in men). Look straight ahead, don't tuck chin or extend neck. Find the narrowest point below the larynx. This is typically where a shirt collar would sit. Common mistake: measuring too high (at jawline) or too low (on shoulders).
Measure at belly button level with stomach relaxed (don't suck in or push out). Stand naturally. Tape should be horizontal all the way around. For women: this is often NOT the narrowest part of waist—measure at belly button regardless. Common mistake: measuring at narrowest point or holding breath.
Measure at widest point of hips and buttocks. Stand with feet together. This is usually 7-9 inches below waist. Tape should be parallel to floor, encompassing fullest part of buttocks. Common mistake: measuring too high (at hip bones) instead of at buttocks.
Absolute accuracy matters less than consistency when tracking progress. Measure wrong spot 1" too low? Not ideal, but if you measure same spot every time, you'll still track changes accurately. Take photos of tape placement for future reference.
Essential Fat (2-5%): Minimum for survival. Only bodybuilders on contest day reach 3-4%, and only for hours. Unsustainable—hormones crash, immune system weakens. No one should target this long-term.
Athletes (6-13%): Elite athletes, fitness models, bodybuilders off-season. Visible abs, vascular arms, defined muscles. Sustainable for some but requires dedicated training/nutrition. 8-10% is "shredded" physique.
Fitness (14-17%): Fit appearance, some ab visibility, good muscle definition. Healthy and sustainable for most active men. Good balance of aesthetics and health.
Average (18-24%): Typical American male. Some softness, minimal muscle definition. No health concerns in this range if lower end. Not "fat" but not lean.
Obese (25%+): Significant health risks increase. Visceral fat accumulates around organs. 30%+ is serious health concern requiring intervention.
Essential Fat (10-13%): Minimum for female health. Below this risks amenorrhea (loss of period), bone density loss, hormonal dysfunction. Only female bodybuilders on contest day. Never sustainable long-term.
Athletes (14-20%): Female athletes, fitness competitors, very fit women. Visible abs possible at lower end. Sustainable for some but may affect menstrual regularity if too low or if rapid weight loss.
Fitness (21-24%): Lean, fit appearance with healthy curves. Muscle definition visible. Excellent health and aesthetics balance. Sustainable long-term for most active women.
Average (25-31%): Typical healthy American woman. Some softness, curves present. No health issues in this range. Lower end (25-27%) still considered fit.
Obese (32%+): Health risks increase. 35%+ significant concern for diabetes, heart disease, joint problems, hormonal issues.
Women require more essential fat than men for reproductive function, breast tissue, and hormonal health. Female body fat targets are 8-10% higher than male equivalents at each category. A woman at 22% body fat has similar leanness/definition to man at 12%.
3-4%: Contest bodybuilder. Striations in muscles, veins everywhere, hollow cheeks. Unsustainable.
6-7%: Bodybuilder off-season, elite physique competitor. Abs in any lighting, visible serratus and obliques, veins in abs.
10-12%: Fitness model, athletic build. Clear 6-pack, visible arm and shoulder definition, some vascularity. Very lean but sustainable for dedicated individuals.
15%: Fit athletic look. 4-pack visible, good muscle definition, flat stomach. Healthy sustainable range.
20%: Average healthy male. No ab visibility, some softness over muscles, normal appearance. Not lean but not "fat."
25%: Some excess fat, love handles present, soft appearance. Beginning of health risk zone.
30%+: Significant excess fat, belly prominent, health risks increase substantially.
12-14%: Figure/bikini competitor contest condition. Visible abs, very defined shoulders and legs, minimal curves. Difficult to sustain, may lose period.
18-20%: Fitness model, athletic physique. Flat stomach, muscle definition visible, healthy curves maintained. Abs visible with flexing.
22-24%: Fit and toned appearance. Flat stomach, some muscle definition, healthy feminine curves. Excellent health and aesthetics balance.
25-27%: Healthy average woman. Soft but not overweight, normal curves, no muscle definition. Medically healthy.
30%: Average American woman. Some excess fat in typical areas (hips, thighs, stomach), soft appearance.
35%+: Significant excess fat, health risks increase. Medical intervention recommended at 40%+.
Fat loss requires burning more calories than consumed. No supplements, meal timing, or food combinations bypass this. Calculate your TDEE (Total Daily Energy Expenditure), eat 300-500 calories below it. One pound of fat = 3,500 calories. 500-calorie daily deficit = 1 lb/week fat loss.
During calorie deficit, body burns both fat and muscle for energy. High protein intake (0.8-1.0g per lb bodyweight) + resistance training preserves muscle mass. Losing 20 lbs but 15 lbs muscle and 5 lbs fat worsens body composition. Goal: lose fat, keep muscle.
Example: 180 lb man wants 180g protein daily. 720 calories from protein leaves 1,000-1,280 for carbs/fats if eating 1,800-2,000 total.
Cardio burns calories but doesn't signal muscle preservation. Resistance training 3-4x/week tells body "I need this muscle," encouraging preferential fat loss. Continue lifting heavy weights even in deficit—don't drop to light weights high reps.
Healthy fat loss: 0.5-1% bodyweight per week. Faster = more muscle loss. Someone at 200 lbs: 1-2 lbs/week. Someone at 150 lbs: 0.75-1.5 lbs/week. Very overweight individuals (35%+ body fat) can lose faster initially (2-3 lbs/week) with acceptable muscle retention.
Weight includes water, food volume, muscle, and fat. You can lose fat while gaining muscle (recomposition), maintaining same weight. Measure body fat monthly. Ideal progress: weight down, body fat % down faster.
Good example: 200 lbs at 25% (50 lbs fat, 150 lbs lean) → 190 lbs at 20% (38 lbs fat, 152 lbs lean). Lost 10 lbs scale weight but 12 lbs fat and gained 2 lbs muscle.
Moderate (300-500 cal deficit): 0.5-1 lb/week loss. Better muscle retention, more energy, easier adherence. Recommended for most people, especially if already lean (<20% men, <28% women).
Aggressive (750-1,000 cal deficit): 1.5-2 lbs/week loss. Faster results but more muscle loss risk, low energy, harder to sustain. Only recommended if obese (30%+ body fat) or time-limited goal.
Metabolic adaptation: As you lose weight, TDEE decreases (less body mass to fuel). What was a 500-cal deficit at 200 lbs may be only 300-cal deficit at 180 lbs.
Reduced NEAT: Non-Exercise Activity Thermogenesis (fidgeting, spontaneous movement) decreases unconsciously during dieting. Can reduce TDEE by 200-400 calories.
Tracking errors: Portion creep, forgetting ingredients, "healthy" food still has calories. Measure/weigh food if stuck.
Water retention: Cortisol from stress and sleep deprivation increases water retention, masking fat loss on scale. Fat loss continues even when scale doesn't move.
Recalculate TDEE: After losing 10-15 lbs, recalculate and adjust calories. Lighter body needs fewer calories.
Increase activity: Add 2,000-3,000 steps daily or one extra training session weekly instead of cutting calories more.
Diet break: Eat at maintenance for 1-2 weeks every 8-12 weeks. Resets hormones (leptin, thyroid), restores NEAT, improves adherence. Then return to deficit.
Track more carefully: Use food scale, measure everything for 1-2 weeks to identify hidden calories.
Prioritize sleep: Poor sleep increases cortisol, reduces insulin sensitivity, increases hunger hormones. 7-9 hours nightly.
Manage stress: Chronic stress raises cortisol, promoting fat storage and water retention. Meditation, walking, hobbies help.
Accuracy: ±1-2%
How it works: Dual-energy X-ray absorptiometry. Scans entire body, measuring bone density, lean mass, fat mass by region.
Pros: Most accurate available outside lab. Shows regional fat distribution. Tracks bone density.
Cons: Expensive ($50-150 per scan). Requires facility visit. Small radiation exposure (equivalent to flying cross-country).
Hydrostatic (Underwater) Weighing
Accuracy: ±2-3%
How it works: Weigh in air vs underwater. Fat floats, muscle sinks—difference calculates body density and body fat.
Pros: Very accurate. Relatively affordable ($40-75).
Cons: Requires complete underwater submersion and breath holding. Availability limited. Uncomfortable for some.
Accuracy: ±2-4%
How it works: Sits in egg-shaped pod. Measures air displacement to calculate body volume and density.
Pros: Quick (5 minutes), no water, accurate.
Cons: Expensive ($50-100), limited availability, claustrophobic for some.
Accuracy: ±5-8%
How it works: Sends electrical current through body. Fat resists, muscle conducts—measures impedance.
Pros: Cheap ($30-300 for home scale), quick, convenient.
Cons: Very inconsistent. Hydration, food, exercise all affect reading. Can vary 3-5% same day. Good for trends if used identically (same time, hydration, pre-meal).
Accuracy: ±3-5% (with experienced tester)
How it works: Pinches fat at specific body sites (3, 7, or 9 locations), measures thickness with calipers, uses formula to estimate total body fat.
Pros: Inexpensive ($10-50), portable, good for tracking changes.
Cons: Requires skill and consistency. Different testers get different results. Hard to self-administer accurately.
Accuracy: ±3-4%
How it works: Circumference measurements (neck, waist, hip) + height. Formula estimates body fat.
Pros: Free, simple, only needs tape measure. Good for field estimation. Consistent when measured same way.
Cons: Assumes standard fat distribution. Measurement errors magnify. Less accurate at extremes.
For tracking progress: use same method consistently. Absolute accuracy matters less than tracking trends. DEXA every 3 months + Navy method weekly provides good combination. Navy method alone works fine if measured carefully and consistently. Don't chase exact number—focus on trend over months.
Men: 10-20% is healthy and sustainable. 14-17% is optimal for most (health + aesthetics). Women: 18-28% is healthy. 21-24% is optimal for most. Athletes may go lower (men 6-13%, women 14-20%) but requires dedicated lifestyle. Essential minimums: 3-5% men, 10-13% women—never go below.
Depends on starting point. Going from 25% to 15% body fat at 180 lbs = losing ~18 lbs fat. At 1.5 lbs/week = 12 weeks. At 1 lb/week = 18 weeks. Factor in plateaus, diet breaks, real life—expect 4-6 months for sustainable 10% body fat reduction. Faster = more muscle loss.
Yes if: (1) Beginner to training, (2) Returning after layoff, (3) Overweight/obese, or (4) Using performance enhancers. Not possible for advanced natural lifters—body builds muscle in surplus, burns fat in deficit. For advanced: alternate bulk and cut phases or maintain/recomp very slowly.
Losing muscle instead of fat worsens body composition. "Skinny fat" result. Solution: protein 0.8-1g per lb, strength train 3-4x/week, moderate deficit (300-500 calories). Preserves muscle while losing fat, improving appearance even at same body fat %.
No. Cannot target fat loss from specific areas. Abs exercises build abs but don't burn belly fat specifically. Fat loss is whole-body process determined by genetics. Some lose face fat first, some thighs, some belly last. Only solution: keep losing fat until problem areas lean out.
Men: 10-12% is lean with abs. Below 10% requires serious dedication, may affect performance and hormones. Stay above 8% unless competing. Women: 18-22% is lean and healthy. Below 18% may affect menstrual cycle. Stay above 15% unless competing. Choose sustainable level you can maintain.