Body Fat Percentage Range Calculator
A free, browser-based calculator. Runs entirely in your browser — no sign up, nothing stored.
1. Your profile
2. Tape measurements
The quick default method. Keep the tape level, snug and not compressing the skin. Tap the “?” next to a field to see where to measure.
Estimated body fat range
Fill in your profile and at least your tape measurements, then press Estimate body fat. This is an educational estimate only.
How to use this calculator
- Confirm you're 18+, then set your sex estimate, age, height and weight.
- Enter your tape measurements (neck, waist/abdomen, and hip for a female estimate) — tap the “?” beside any field to see where to measure.
- Optionally turn on skinfolds for a caliper-based method, then press Estimate body fat.
How it works
Estimate a possible adult body fat percentage range from height, weight, tape measurements and optional skinfolds — an educational body-composition estimate only, never a medical diagnosis or an exact figure.
It runs several population formulas — the US Navy tape (circumference) method, Jackson-Pollock 3-site and 7-site and Durnin-Womersley 4-site skinfolds, with a low-confidence BMI fallback — then shows a range, a likely estimate, fat and lean mass, BMI and waist ratios. When more than one method is available the spread between them forms the range; with one method a transparent confidence band is used. Everything runs in your browser and nothing is stored.
Worked example
Male, 182 cm, 80 kg, neck 39 cm, abdomen 86 cm. The Navy tape method estimates roughly 16% body fat, shown as a range with estimated fat and lean mass. Adding skinfolds narrows and cross-checks the estimate.
Tips
- Measure at the same time of day under similar conditions to track changes fairly.
- Keep the tape level and snug but not compressing the skin; repeat each skinfold site a couple of times for consistency.
- Use the result for general fitness tracking, not as a clinical or medical assessment.
Frequently asked questions
How accurate is this body fat calculator?
It is an approximate estimate, not an exact or medical-grade measurement. Tape and skinfold formulas are based on population averages, so results vary with measurement technique, hydration, age, body shape, muscle mass and the method used. That's why we always show a range.
Which method should I use?
Tape (the Navy method) is the easy default and only needs a flexible tape. If you own calipers and can measure carefully, skinfold methods (especially Jackson-Pollock 7-site) can be more informative. BMI alone is only a rough, low-confidence fallback.
Is my measurement data stored?
No. Every calculation runs in your browser. Nothing you enter is uploaded, saved or sent to any server.
Can children or teens use it?
No — this adult calculator (18+) uses adult formulas. Children and teens need age- and sex-specific BMI-for-age percentiles because they're still growing, which is a separate calculation.
Related tools
Tip: Enter any known values to calculate the remaining results.
All calculations run in your browser. Your inputs are never saved or transmitted.