Introduction
The number on a bathroom scale can't tell you what your body is actually made of. Two people with the same weight and height can carry very different amounts of muscle and fat, which is why body fat percentage is a far more useful figure than weight alone if your goal is fitness, weight management, or simply understanding your own health.
This calculator gives you two ways to get that figure. If you have a soft tape measure, the tape method uses your neck, waist, and (for women) hip measurements to produce a close estimate of your true body composition. If you'd rather skip the measuring and just want a quick body fat percentage calculator using height and weight, the second method gives you a fast estimate from those two numbers plus your age and gender.
How to calculate body fat percentage at home
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Pick a method
Choose the tape method for a more accurate reading, or the height and weight method if you just want a quick ballpark figure.
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Take your measurements
For the tape method, measure your neck and waist in a relaxed, standing position, keeping the tape level and snug but not tight. Women also measure around the widest part of the hips.
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Enter your details
Add your gender, age, and height, then either your weight or your tape measurements, depending on the method you picked.
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Read your result
Press calculate to see your estimated body fat percentage, which category it falls into, and where that sits on the scale below the number.
What this calculator offers
- Two calculation methodsSwitch between a tape-measurement method and a height and weight only estimate, depending on what information you have.
- US and metric unitsEnter measurements in inches and pounds, or centimetres and kilograms, without doing any conversion yourself.
- Gender-specific rangesResults are compared against separate category ranges for men and women, since healthy fat levels differ by gender.
- Instant visual scaleA marked scale shows exactly where your number falls, from essential fat through to the obese range.
- No account or app neededEverything runs directly in this page. Nothing is uploaded, stored, or emailed anywhere.
Who can use this calculator
This tool is built for adults who want a general estimate of their body composition, including people starting a fitness routine, anyone tracking progress during a weight loss or muscle-building programme, and people who are simply curious how their body fat compares to standard ranges.
It's not designed for children, pregnant women, or people with a very high level of athletic muscle mass, since the underlying formulas were built from general adult population data and can be less accurate for those groups. If you fall into one of those categories, a skinfold measurement or a body composition scan from a health professional will give you a more reliable number.
How body fat is calculated
The tape method on this page is based on the U.S. Navy circumference formula, first developed for military fitness testing and still used today, including in the calculations behind the body fat percentage calculator the Army and other services use for tape tests. It estimates body fat from the relationship between your waist, neck, and height, plus hip measurement for women.
Men: BF% = 495 / (1.0324 − 0.19077 × log10(waist − neck) + 0.15456 × log10(height)) − 450
Women: BF% = 495 / (1.29579 − 0.35004 × log10(waist + hip − neck) + 0.22100 × log10(height)) − 450
The height and weight method uses the Deurenberg formula, which estimates body fat from your Body Mass Index (BMI), age, and gender. It's less precise than a tape measurement because it can't distinguish muscle from fat, but it's a reasonable quick check when you don't have a tape measure on hand.
BMI-based: BF% = 1.20 × BMI + 0.23 × age − 10.8 × (1 if male, 0 if female) − 5.4
Is your result normal?
"Normal" depends on your gender, age, and how active you are. The ranges below, based on classifications from the American Council on Exercise, give a general idea of where different body fat levels sit.
| Category | Women | Men |
|---|---|---|
| Essential fat | 10–13% | 2–5% |
| Athletes | 14–20% | 6–13% |
| Fitness | 21–24% | 14–17% |
| Average | 25–31% | 18–24% |
| Obese | 32% and above | 25% and above |
Falling in the "average" band isn't a problem on its own, and being in the "athletes" band doesn't automatically mean you're healthier. These bands describe common ranges, not a verdict on your health. Trends over time, how you feel, and other health markers matter more than any single reading.
Suggestions for controlling fat
- Get your result firstPress "Calculate body fat" above and this section fills with suggestions matched to the category your result falls into.
- Small deficits beat crash dietsA modest, consistent calorie shortfall is easier to hold and preserves muscle better than aggressive restriction.
- Keep muscle while losing fatStrength training and enough protein mean more of the weight you lose comes from fat.
- Move more, sit lessEveryday activity — walking, stairs, standing — adds up faster than most people expect.
- Recheck every few weeksBody composition changes slowly, so a fortnightly trend is far more useful than a daily number.
Conclusion
Body fat percentage gives you a more complete picture of your health than weight or BMI alone, and you don't need special equipment to get a workable estimate. Whether you use a tape measure for a closer result or just your height and weight for a quick check, the number matters most as part of a trend you track over time, rather than as a single reading to judge yourself against.
Frequently asked questions
How accurate is a body fat percentage calculator?
The tape method typically comes within a few percentage points of results from a DEXA scan or hydrostatic weighing when measurements are taken carefully. The height and weight method is less precise since it can't tell muscle from fat, so treat it as a rough estimate rather than a clinical reading.
Can I calculate body fat percentage without neck and waist measurements?
Yes. Switch the calculator to "Height & weight" mode above. It estimates body fat from your BMI, age, and gender instead of tape measurements, which is useful if you don't have a measuring tape or would rather skip the extra steps.
Is this the same as the Army body fat calculator?
It uses the same underlying circumference method the U.S. military uses for tape testing, which measures neck, waist, and, for women, hip circumference against height. Official military standards may apply slightly different rounding rules or additional site measurements, so treat this as a close civilian equivalent rather than an official score.
Why do men and women have different healthy ranges?
Women naturally carry more essential fat than men, largely due to hormonal and reproductive function, so a body fat percentage that would be considered low for a woman is closer to typical for a man. That's why this calculator compares your result against gender-specific ranges.
Should I use body fat percentage or BMI to track progress?
Body fat percentage is more informative because it separates fat mass from muscle mass, while BMI only compares weight to height. Someone with a lot of muscle can have a "high" BMI while carrying a low, healthy body fat percentage.
How often should I recheck my body fat percentage?
Every two to four weeks is usually enough to see a meaningful trend. Body composition doesn't change quickly enough for daily measurements to be useful, and small day-to-day shifts are usually just water weight.