Free Tools
Body Fat Calculator
Estimate your body fat percentage with the US Navy tape-measure method — no calipers, no scan. Enter a few measurements and get your body fat, your category, and your lean and fat mass.
No sign-up, no maths. It is the same field formula the military uses, and it only needs a tape measure.
The formula and healthy ranges differ by sex — women also measure the hip.
Measure relaxed with a tape held snug, not tight. Waist at the navel, neck below the larynx.
Add your weight to also see your fat mass and lean (fat-free) mass.
Enter your height, neck and waist measurements to see your body fat.
Nutrition tool
TDEE & Macro Calculator
Know your body fat? Now set the calories and macros to change it — cut, maintain or bulk.
Strength tool
One-Rep Max Calculator
Estimate your 1RM from any set, then get your training loads at every percentage.
What is body fat percentage?
Body fat percentage is the share of your total bodyweight that is fat, as opposed to muscle, bone, organs and water. It tells you far more than the scale or BMI alone: two people at the same weight can look and perform completely differently depending on how much of that weight is lean tissue. For anyone lifting, it is the number that actually tracks whether a cut or a bulk is going the right way.
How to measure properly
Use a flexible tape and measure relaxed, first thing in the morning if you can. Neck: just below the larynx, tape sloping slightly down at the front. Waist: at the navel for men, at the narrowest point for women. Hip (women): around the widest part of the glutes. Keep the tape snug against the skin but not digging in, and take each reading twice. Consistency between measurements matters more than any single number.
Reading your result
The tool sorts you into a category and shows the full scale for your sex, so you can see how far you are from the range you want. Chasing the essential-fat floor is not the goal — very low body fat comes with real hormonal and health costs. Most lifters do best sitting in the athletic-to-fitness band, lean enough to look strong and stay healthy, with enough fuel to actually train hard.
Common questions
How does the US Navy body fat calculator work?+
It estimates body fat from a few tape measurements rather than skinfold calipers or a scan. Men enter height, neck and waist; women add the hip. The formula, developed by the US Navy, uses the ratio between your waist and neck (and hip for women) relative to height, because fat tends to gather around the midsection. It is a well-validated field method that needs no special kit.
How accurate is it?+
For most people it lands within about 3 to 4 percentage points of a DEXA scan, which is good for a free tape-measure tool. Accuracy depends entirely on consistent measuring: keep the tape snug but not tight, measure at the same spots each time, and track the trend over weeks rather than fixating on a single reading. It can read high for very muscular, thick-waisted lifters and low for very lean people.
What is a healthy body fat percentage?+
For men, roughly 6 to 17 percent is the athletic-to-fitness range and 18 to 24 percent is average; 25 percent and above is classed as above average. For women the same bands sit about 8 points higher (14 to 24 percent fit, 25 to 31 percent average, 32 percent plus above average) because women carry more essential fat. Dropping below the essential floor is not a goal to chase — it can harm hormones and health.
How do I actually lower my body fat?+
Body fat comes down in a calorie deficit held consistently over time, with enough protein and resistance training to keep the muscle you already have. Work out your maintenance calories, eat below them, and hit roughly 2 grams of protein per kg of bodyweight. No supplement burns fat in any meaningful way; the ones that help are the ones that make the deficit easier to sustain, like whey to hit protein.
Is this medical advice?+
No. It is a general, evidence-based estimate for healthy adults, not a clinical body-composition measurement or medical advice. If you have a health condition or are making big changes to your diet or training, speak to a qualified clinician or dietitian.
Ready to change the number?
Body composition changes in the kitchen: a steady calorie deficit and enough protein to hold your muscle. Set your calories with the TDEE tool, then use the products scored 0–100 on the evidence to close your protein gap.
Informational only — not medical advice. Body fat is an estimate from a field formula, not a clinical measurement. Buy links are affiliate links; we may earn a commission at no extra cost to you.