Body Fat Calculator
Estimate body fat with Navy & YMCA methods, lean mass, body shape and a fat-loss plan.
Body fat ≈ —
Where you sit (fat category)
Body shape analysis
Fat-loss goal planner
Personalised guidance
How to use the Body Fat Calculator
Step 1 — Enter your details
- Add your measurements and pick your options.
Step 2 — Read the dashboard
- Results, gauge and breakdown update instantly.
Step 3 — Explore the detail
- Review the per-method figures and personalised guidance.
Step 4 — Export
- Download a PDF report or print it.
Frequently asked questions
Two circumference methods: the U.S. Navy formula (from neck, waist and — for women — hips) and the YMCA formula (from waist and weight). It shows both and their average, which is more robust than either alone.
For most people they land within a few percentage points of clinical testing — good for a free, no-equipment estimate and excellent for tracking change. They are not as precise as a DEXA scan, especially at the extremes.
Lean body mass is everything that is not fat — muscle, bone, organs and water. Preserving it during weight loss is the goal, which is why protein and strength training matter; the tool shows your lean and fat mass in weight terms.
If you enter hips, it computes your waist-to-hip ratio and classifies an "apple" (central) or "pear" (lower-body) fat pattern. Central fat carries more metabolic risk, so it is the more important target.
With a flexible tape, snug but not compressing the skin, on a relaxed breath, at the same time of day each time for consistent tracking. This tool gives general information for education, not medical or dietetic advice; consult a qualified professional for guidance about your health.
About the Body Fat Calculator
This tool estimates your body-fat percentage from simple tape measurements using two recognised methods — the U.S. Navy and YMCA formulas — and turns the result into a fuller picture: your lean and fat mass, your fitness category, a body-shape analysis, and a safe fat-loss plan, all exportable as a report.
Two methods, cross-checked
Body fat matters more than weight for health and fitness, but the scale and BMI cannot see it. The Navy method reads your body’s shape from neck, waist and (for women) hip measurements, while the YMCA method works from waist and weight; each has strengths, so the tool reports both and their average for a steadier estimate. For most people the result sits within a few percent of clinical testing — not lab-grade, but reliable enough to track real progress when you measure consistently.
Composition, shape and a safe plan
From your body-fat percentage the tool derives lean body mass and fat mass in weight terms, which reframes a goal usefully: the aim is to lose fat while keeping lean mass, not simply to drop scale weight. If you provide hips, a waist-to-hip ratio classifies an apple or pear fat pattern and flags that central fat is the higher-risk, higher-priority target. The fat-loss planner then calculates the weight to lose to reach a chosen body-fat percentage — holding lean mass constant — over a safe timeline of about half a kilo per week.
Measure well, track the trend
Accuracy depends on good measurements: a snug (not tight) tape, relaxed breath, same time of day. Body fat changes slowly, so the trend over weeks matters far more than any single reading. This tool gives general information for education, not medical or dietetic advice; consult a qualified professional for guidance about your health. Pair it with the Calorie Calculator to plan intake and the BMI Calculator for context.