Body Fat Calculator
Measure your neck, waist (and hips, for women) with a soft tape measure, enter your numbers below, and get your body fat percentage, category and lean mass instantly in metric, US or stone units.
Fill in your measurements and press Calculate to see your body fat percentage, category and lean mass.
Body Fat Calculator: Calculate Your Body Fat Percentage
A body fat calculator provides you with a quick and easy, tape-measure measurement of your percentage body fat, without having to book an expensive scan.
Then, we will explain what body fat percentage is, how to measure body fat at home, the range of healthy body fat percent by age and gender, and compare it with other body fat measurement techniques.
What Is Body Fat Percentage?
Body fat percentage is the amount of fat that makes up a person’s total body weight, rather than the amount of lean mass (muscle, bone, organs, and water).
Bathroom scales aren’t nearly as indicative of body fat percentage as a body fat percentage calculator is, because two people can weigh the same and have different body compositions.
There are two types of body fat to know:
- Essential fat is required for the production of hormones, protection of the organs, and for basic functioning (2-5% in men and 10-13% in women).
- Fat deposited into fat cells (what most people refer to as “body fat %”)
How to Calculate Body Fat Percentage (Navy Method)
The U.S. Navy circumference formula is the most common free formula used for determining body fat (and the formula we used in our navy body fat calculator above).
It was created in 1984 specifically for army fitness testing (the same concept as most army body fat calculator programs require), and only requires a soft tape and your height.
The formula uses:
- Neck circumference
- Waist circumference
- Hip circumference (women only)
- Height
Compared to hydrostatic (underwater) weighing, the Navy method is typically accurate within 3–4% making it one of the best free ways to calculate body fat without lab equipment.
How to Measure Body Fat at Home
- Neck: Wrap the tape just below the larynx (Adam’s apple), sloping slightly downward at the front.
- Waist: Measure at the narrowest point, usually level with the navel, without compressing the skin.
- Hip (women only): Measure around the widest part of the hips and glutes.
Take each measurement two to three times and average the results — this is the single biggest factor in how to determine body fat percentage accurately with a tape.
Body Fat Percentage Chart for Men and Women
Once you know your number, compare it against the American Council on Exercise (ACE) classification, the standard reference chart used by trainers and gyms worldwide.
Category | Men | Women |
Essential Fat | 2–5% | 10–13% |
Athletes | 6–13% | 14–20% |
Fitness | 14–17% | 21–24% |
Average | 18–24% | 25–31% |
Obese | 25%+ | 32%+ |
For context: male body fat percentage in the “fitness” range (14–17%) is where most visible ab definition starts to appear, while women typically need to reach the upper end of the “athletes” range for the same look, due to naturally higher essential fat.
Other Ways to Measure Body Fat Percentage
The tape-measure method isn’t the only option. Here’s how it compares to other common tools:
Method | Typical Accuracy | Cost | Convenience |
Navy tape method | ±3–4% | Free | Very high |
Skinfold calipers | ±3–5% | Low | Medium |
Bioelectrical Impedance (BIA) scale | ±4–8%, hydration-sensitive | Low–Medium | High |
DEXA scan | ±1–3% (gold standard) | High | Low |
Hydrostatic (underwater) weighing | ±2–3% | High | Low |
If you want a quick, repeatable fat percentage calculator you can use weekly to track trends, the tape method or a BIA scale are the most practical. DEXA and hydrostatic weighing are more precise but require a clinic visit.
Ideal Body Fat Percentage by Age
Body fat naturally increases with age as muscle mass and metabolic rate decline — so the “ideal” figure isn’t static. Research from Jackson & Pollock is commonly used to set age-adjusted targets:
- 20s: ~10–12% (men), ~18–20% (women)
- 30s: ~13–15% (men), ~19–21% (women)
- 40s: ~16–18% (men), ~21–23% (women)
- 50s+: ~18–20% (men), ~23–25% (women)
A 50-year-old man at 19% body fat may be right at his ideal, while the same number would sit above ideal for a man in his 20s.
Body Fat Percentage vs. BMI
BMI only considers height and weight and often classifies muscular people (who have a low body fat percentage) as overweight. Instead, a body fat percentage calculator can tell you
What your body actually contains that is, the metabolically active visceral fat (around organs) from the subcutaneous fat (under the skin) hence the shift to using it along with your BMI when doctors begin to advise combining the two to get a better sense for how healthy or unhealthy you are.
FAQs
What is a good body fat percentage for men?
According to ACE, 14–17% is considered “fitness” level, and 18–24% is average/acceptable for adult men.
What is a good body fat percentage for women?
21–24% is fitness level, and 25–31% is average/acceptable, since women require more essential fat than men.
How accurate is a body fat calculator?
The Navy method used in most free calculators is typically accurate within 3–4% compared to underwater weighing, making it reliable for tracking progress over time.
What body fat percentage shows abs?
Visible abs typically appear around 10–14% for men and 16–20% for women, though this varies with individual muscle development.
How can I reduce my body fat percentage? A sustained calorie deficit combined with resistance training to preserve muscle mass is the most effective, evidence-based approach — aim for a gradual 0.5–1% body fat loss per month rather than crash dieting.