This body fat calculator estimates your body fat percentage using the U.S. Navy circumference method — the same tape-measure approach the military has used for decades. Enter your height and neck, waist (and hip for women) measurements to get your body fat percentage, fat mass, lean body mass and category, plus a BMI-based cross-check.
What Is a Body Fat Calculator?
A body fat calculator estimates what percentage of your total weight is fat tissue, as opposed to lean mass — muscle, bone, organs and water. Two people with the same weight and the same BMI can look and perform very differently because of body composition, which is why body fat percentage tells you more than the scale alone. This calculator uses the circumference method developed by the U.S. Navy, cross-checked with a BMI-based formula, and needs nothing more than a tape measure.
It sits in our Health Calculators collection alongside the BMI Calculator. BMI is quicker; body fat percentage is more informative. Used together, they give a fuller picture than either alone.
How to Measure (This Decides Accuracy)
- Height: barefoot, standing straight.
- Neck: just below the Adam’s apple, tape perpendicular to the neck, shoulders relaxed.
- Waist: for the Navy method, at the navel for men; at the narrowest point of the abdomen for women. Keep the tape snug, not compressing the skin, and measure after a normal exhale.
- Hip (women only): at the widest point of the buttocks.
- Measure twice and average. A quarter-inch error at the waist can move the result by about a percentage point.
Body Fat Calculator Examples (Verified)
- Man: height 70 in, neck 15 in, waist 34 in → 17.1% body fat — the “Fitness” category.
- Woman: height 65 in, neck 13 in, waist 30 in, hip 38 in → 28.6% — the “Average” category.
Body Fat Percentage Categories (ACE)
| 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%+ |
Women carry more essential fat than men, so the healthy ranges differ by sex — never compare across the two columns. For a healthy-weight range by height, pair this with our Ideal Weight Calculator.
Army Body Fat Calculator (2026) and the Navy Method
Searches for an “army body fat calculator 2026” have surged because the U.S. Army replaced its old multi-site tape test with a newer standard built around a single abdominal circumference measurement (at the navel), combined with height and weight in the Army’s official equation. Soldiers must meet body fat standards assessed this way, alongside the Army Fitness Test (AFT).
The U.S. Navy method used in this calculator is the classic multi-site version: neck and waist for men, neck, waist and hip for women. If you are estimating for Army purposes, measure your waist exactly at the navel as the Army does — the estimate will be a useful planning figure, but only the Army’s official assessment counts for record. For daily calorie and training targets once you know your body fat, use our TDEE Calculator and Protein Calculator.
How Accurate Is a Tape-Measure Body Fat Calculator?
Against laboratory methods (DEXA, hydrostatic weighing), the Navy circumference method is typically within about 3–4 percentage points for most people. That is far better than BMI alone for muscular or very lean people, and consistent enough to track change over time — which is what matters most. Recheck monthly under the same conditions rather than chasing daily precision.
Related Tools
- BMI Calculator — the quick weight-for-height index
- Ideal Weight Calculator — healthy weight ranges by height
- TDEE Calculator — daily calories from your stats
- Protein Calculator — daily protein for your body and goal
Frequently Asked Questions
What is a healthy body fat percentage?
For men, roughly 14–17% is the “fitness” range and 18–24% average; for women, 21–24% is fitness and 25–31% average. Athletes run lower. Below essential fat (under 5% men, 13% women) is not healthy to sustain.
Is the Navy body fat calculator accurate?
It is one of the most accurate tape-measure methods, usually within 3–4 points of DEXA when measurements are taken carefully. Measure at the same time of day, in the same spots, for comparable results.
What is the Army’s body fat standard in 2026?
The Army uses a one-site abdominal circumference method with its own official equation and sex/age-based standards. This page explains the method and gives a close estimate with the Navy formula; official scores come only from an Army assessment.
Can I calculate body fat from BMI only?
Yes — the Deurenberg formula used as the cross-check here does exactly that, from BMI and age. It is less accurate than tape measurements, especially for muscular people, which is why this calculator shows both.
Should I use calipers or a smart scale instead?
Calipers are good in trained hands; smart-scale (bioimpedance) readings swing with hydration. All home methods are estimates — pick one and track the trend.
Is this body fat calculator free?
Yes — free, instant, no sign-up, and your measurements never leave your browser.