The US Navy method estimates body fat from height and circumference measurements: neck and waist for men, plus hips for women. Add your weight to see fat mass and lean mass. Estimate body fat percentage with a tape measure, using the US Navy formula.
What does this tool do?
Estimates body-fat percentage from tape measurements (neck, waist, hips) using the U.S. Navy method — no calipers or scans needed. Shows the category (athletic … obese) and lean mass estimate.
Because the math runs locally, the Body Fat Calculator works offline after the page loads and never queues behind a server — handy during load-shedding or on slow mobile data. There is nothing to install and no account to create; the page is the whole application, ready in the time it takes to open a tab.
The interface keeps things practical: the inputs are “Units”, “Height”, “Neck”, “Waist (at navel)”, “Hips (widest point)” and “Weight (kg or lb, optional)”; the “u” control offers “Centimetres” and “Inches”. Results update live as you work — there is no waiting and nothing to submit.
How do I use this tool?
Enter your figures below — every result updates the instant you type, so comparing scenarios is just a matter of changing a number and watching the answer move.
- Enter your values in “Units”, “Height”, “Neck” and the other fields.
- Results update instantly as you type — no button to press.
How does it work?
U.S. Navy formula: men use abdomen−neck and height; women add hips. It is a logarithmic regression fitted to hydrostatic weighing data — practical within a few percentage points for most people.
The formula used is the standard one taught and published for this calculation — the tool does not invent methods. Where conventions differ (rounding, day-count, tax treatment), the page follows the common Pakistani practice and says so, so the result matches what local institutions expect.
Use cases in Pakistan
Gyms across Pakistan use tape-measure body-fat checks for transformation challenges; it beats the scale for tracking fat loss vs muscle gain. Recruitment medicals and sports selections reference body composition more than raw weight.
Families use it for household budgeting and school-fee planning; small businesses for pricing and payroll math; students for everything from BISE numericals to CSS preparation. Wherever the same calculation is repeated monthly — bills, salaries, savings targets — this page replaces the phone-calculator ritual.
Limitations
Estimates ±3–4% vs lab methods (DEXA/hydrostatic); tape placement and time of day shift results. Very lean or very obese bodies fall outside the formula’s fitted range — treat extremes cautiously.
Assumptions are stated on the page — read them before trusting the headline number for money, health or legal decisions. A calculator amplifies the quality of its inputs: careful numbers in, trustworthy numbers out.
Frequently asked questions
How do I measure correctly?
Tape snug, not compressing: neck below the Adam’s apple, waist at the navel, hips at the widest. Measure in the morning, relaxed. For figures that go into applications or documents, double-check the inputs against the source — the math is exact, but only for the numbers you enter.
Why track body fat instead of weight?
Weight mixes fat, muscle and water. Body-fat % shows whether your diet/training is actually changing composition. Try varying one input at a time to see which assumption drives the result; that sensitivity check is often more valuable than the headline number.
What is a healthy body-fat %?
Roughly 10–20% men, 18–28% women for fitness; athletes lower. Age shifts the healthy range upward slightly. Save or screenshot the result with its inputs when the figure matters later — reconstructing “what did I enter?” is harder than it sounds.
How accurate is the Navy method?
Within ~3–4% of lab measurements for most people — good for tracking trends, not medical diagnosis. For figures that go into applications or documents, double-check the inputs against the source — the math is exact, but only for the numbers you enter.
Is my data uploaded or stored?
No. This tool runs entirely in your browser — what you type or paste never leaves your device, is never sent to a server, and is never stored. Closing the tab removes all trace. Try varying one input at a time to see which assumption drives the result; that sensitivity check is often more valuable than the headline number.
Is it really free? Do I need an account?
Yes, free, and no account needed. Open the page and use it — no sign-up, no trial, no watermark on results. Save or screenshot the result with its inputs when the figure matters later — reconstructing “what did I enter?” is harder than it sounds.
Updated October 2026 · Built and tested by Sharjeel Tahir · How our tools are tested