Fitness
Body Fat Calculator
By the Dailycaltor team · formula-verified · last updated July 2026
Estimate body fat with a tape measure.
Details
Formula
US Navy method (metric): men use log10(waist − neck) and log10(height); women add the hip measurement: log10(waist + hip − neck). It estimates body density from circumference, then converts to body-fat percent.
Worked examples
- Male 175 cm, neck 38, waist 85 → roughly 18–19%.
- A 3 cm waist reduction typically drops the estimate 1–2 points.
- Female estimates include hips, reflecting different fat distribution.
Common mistakes
- Measuring over clothes or pulling the tape tight — measure snug on skin, relaxed.
- Taking waist at the narrowest point instead of the navel.
- Treating tape estimates as scan-accurate; expect ±3–4% versus DEXA.
Source: US Navy circumference method. Last updated: July 2026. Educational estimates only.
Questions
How accurate is the Navy method?
Within roughly 3–4% of lab methods for most people — good for tracking trends.
What is a healthy body fat percentage?
Commonly cited fit ranges: ~14–17% men, ~21–24% women; athletes lower, essential minimums lower still.
When should I measure?
Morning, before eating, same conditions each time — consistency beats precision.
Why do women carry more fat?
Essential fat requirements are higher; healthy ranges differ by design, not fitness.
Is BMI or body fat better?
They answer different questions; body fat distinguishes muscle from fat where BMI cannot.