Estimate your body fat percentage using the US Navy method, just a tape measure needed. No gym equipment, no expensive scans.
Free to use
Tape measure only
Navy formula method
Lean mass breakdown
Body Fat % Estimator
US Navy method, tape measure only
How to take accurate measurements
1. Use a flexible tape measure pulled snug but not compressing skin.
2. Measure in the morning before eating or drinking.
3. Take each measurement twice and use the average.
4. Stand relaxed, don't flex or hold your breath.
cm
cm
cm
cm
kg
-
% body fat
Fat Mass-
Lean Mass-
Category-
To Athletic Range-
Body Fat Categories
Body Composition Breakdown
Fat
-
Muscle
-
Bone + Other
-
The Navy method is accurate to within -3-4% for most people. For greater precision, consider a DEXA scan or hydrostatic weighing. Avoid measuring after exercise, eating, or drinking.
The Guide
How To Estimate Body Fat % With A Tape Measure
The US Navy circumference method uses simple body measurements to estimate body fat percentage. It was developed by Hodgdon and Beckett in 1984 for the US Navy and is one of the most widely used field methods because it requires no special equipment, just a flexible tape measure.
The formula uses your height, neck and waist circumference (and hip for women) to calculate an estimate of body density, from which body fat percentage is derived. While not as accurate as a DEXA scan, it gives a useful estimate accurate to within -3-4% for most people.
Minimum for bodily functions. Not sustainable long term.
Athletic
6 - 13%
Typical of competitive athletes. Visible muscle definition.
Fitness
14 - 17%
Lean, healthy appearance. Good muscle visibility.
Average
18 - 24%
Healthy range. Some muscle, some fat coverage.
Obese
25%+
Elevated health risk. Fat loss recommended.
Body Fat Categories for Women
Category
Body Fat %
Description
Essential fat
10 - 13%
Minimum for hormonal and bodily function.
Athletic
14 - 20%
Competitive athlete range. Defined musculature.
Fitness
21 - 24%
Lean and healthy. Good general fitness level.
Average
25 - 31%
Healthy range for most women.
Obese
32%+
Elevated health risk. Fat loss recommended.
How To Improve Your Body Fat %
The most effective approach to reducing body fat is a moderate calorie deficit combined with resistance training. The calorie deficit drives fat loss, while lifting weights ensures you preserve the muscle underneath, so your body composition improves even more than the scale would suggest. Aim for a 500 kcal/day deficit and at least 3 resistance training sessions per week.
For those looking to reduce body fat while maintaining or gaining muscle (body recomposition), eating at or very close to maintenance with high protein intake (2g/kg of bodyweight) and consistent progressive training is the most effective strategy.
Frequently Asked Questions
The Navy method is accurate to within approximately -3-4% for most people when measurements are taken correctly. It tends to be most accurate for people with average body proportions and less accurate for very muscular individuals or those with unusual fat distribution patterns. For reference, DEXA scans (the gold standard) are accurate to -1-2%.
For the Navy method, measure your waist at the narrowest point, usually around the navel or just above it. Do not suck in your stomach. Exhale normally and measure after the exhale. Keep the tape parallel to the floor and snug but not compressing the skin.
Measure every 4 weeks at the same time of day (morning is best) under the same conditions. Daily measurements are too variable due to water retention, food volume, and other factors. Monthly measurements give you a clear trend without the noise of daily fluctuation.
At a 500 kcal/day deficit you'll lose roughly 0.5kg per week, of which the majority will be fat. In terms of body fat percentage, you might see a reduction of around 0.5-1% per month depending on your starting point. The leaner you are, the slower progress becomes as your body protects remaining fat stores more aggressively.
For most people, yes, body fat percentage is a more meaningful indicator of health and fitness because it directly measures the ratio of fat to lean tissue. BMI can't distinguish between muscle and fat, so a muscular person and an unfit person of the same height and weight will have identical BMIs but very different body compositions and health profiles.
