% Weight Loss Percentage

How to Calculate Body Fat Percentage — 5 Methods Explained (Canada)

By Weight Loss Percentage Editorial Team  |  Reviewed by Dr. Sarah Jenkins, RD  |  July 2026  |  10 min read

Body fat percentage is one of the most important metrics for tracking your health and fitness. Unlike scale weight or BMI, it tells you exactly how much of your body is fat tissue versus muscle, bone, and water. In this guide, we cover 5 ways to calculate body fat percentage — from free home methods to clinical gold standards.

Key Takeaways
  • The US Navy circumference method is the most accurate free home method (±3-4%)
  • DEXA scan is the clinical gold standard (±1-2%) but costs $50-150
  • Healthy body fat is 21-31% for women and 14-24% for men
  • Body fat % is more useful than BMI for tracking body composition changes
  • Measure every 4-6 weeks for meaningful trend data

Method 1: US Navy Circumference Method (Best Free Method)

The US Navy method is the most practical and accurate way to calculate body fat percentage at home. It uses a tape measure — no equipment purchase needed — and is accurate to within 3-4% of DEXA scans. This is the method used by the US military for mandatory fitness standards testing.

What You Need

How to Measure (Tips for Accuracy)

The US Navy Body Fat Formula

For Men:

Body Fat % = 495 ÷ (1.0324 − 0.19077 × log₁₀(waist − neck) + 0.15456 × log₁₀(height)) − 450

For Women:

Body Fat % = 495 ÷ (1.29579 − 0.35004 × log₁₀(waist + hip − neck) + 0.22100 × log₁₀(height)) − 450

This formula involves logarithms — use our free Body Fat Percentage Calculator to get your result instantly.

Example (Men): Waist = 34", Neck = 15", Height = 70"
Body Fat % = 495 ÷ (1.0324 − 0.19077 × log(19) + 0.15456 × log(70)) − 450 ≈ 17.8% (Fitness category)

Method 2: BMI-Based Body Fat Estimation

If you only have your BMI, you can estimate body fat percentage using the Deurenberg formula. This is less accurate than circumference methods (±5-6%) but works if you have no tape measure.

Body Fat % = (1.20 × BMI) + (0.23 × Age) − (10.8 × Sex) − 5.4
(Sex: 1 = male, 0 = female)

Example: A 35-year-old woman with BMI 24:
Body Fat % = (1.20 × 24) + (0.23 × 35) − (10.8 × 0) − 5.4 = 28.8 + 8.05 − 0 − 5.4 = 31.45% (Acceptable range)

Get your BMI first with our BMI Calculator for Women and Men.

Method 3: Skinfold Calipers

Skinfold calipers measure the thickness of subcutaneous fat at specific body sites. A trained technician pinches fat at multiple points (typically 3, 4, or 7 sites) and enters the values into a formula.

Popular formulas include Jackson-Pollock 3-site (chest, abdomen, thigh for men; triceps, suprailiac, thigh for women) and Jackson-Pollock 7-site for higher accuracy.

Method 4: Bioelectrical Impedance Analysis (BIA)

BIA scales and handheld devices send a small electrical current through your body. Since fat and muscle conduct electricity differently, the device estimates body composition.

Tip for BIA accuracy: Always measure at the same time of day (first thing in the morning, after using the bathroom, before eating or drinking) for consistent comparative readings.

Method 5: DEXA Scan (Gold Standard)

Dual-Energy X-ray Absorptiometry (DEXA) is the clinical gold standard for body composition measurement. It distinguishes fat mass, lean mass, and bone mineral density with exceptional precision.

DEXA is ideal for an accurate baseline measurement once or twice per year. Use a free method like the US Navy formula for monthly tracking between DEXA scans.

Method Comparison

Method Accuracy Cost Best For
US Navy Formula±3-4%FreeRegular monthly tracking
BMI Estimation±5-6%FreeQuick rough estimate
Skinfold Calipers±3-5%$10-50Gym/fitness testing
BIA Scale±3-8%$20-200Daily/weekly convenience
DEXA Scan±1-2%$50-150Annual baseline

Healthy Body Fat Percentage Ranges

Category Women Men
Essential Fat10-13%2-5%
Athletic14-20%6-13%
Fitness21-24%14-17%
Acceptable25-31%18-24%
Obese32%+25%+

How to Lower Your Body Fat Percentage

Once you know your body fat percentage, here is how to lower it:

  1. Create a moderate calorie deficit (300-500 cal/day) — Use our weight loss calculator for your personalized target
  2. Hit 0.7-1.0g protein per pound of body weight — Use our protein calculator
  3. Resistance train 3-4x per week — Preserves muscle while losing fat
  4. Track progress every 4-6 weeks — Use our body fat percentage calculator

Frequently Asked Questions

What is the easiest way to calculate body fat percentage at home?

The US Navy circumference method is the best free home option. Measure waist and neck (men), or waist, hips, and neck (women), then use our free body fat percentage calculator — accurate to ±3-4%.

How accurate is the US Navy body fat formula?

Studies show it is accurate to within 3-4% of DEXA scans. It is the method used by the US military for mandatory fitness standards testing — a strong endorsement of its reliability.

Can you calculate body fat percentage from BMI?

Yes, approximately. The Deurenberg formula estimates body fat from BMI, age, and sex: BF% = (1.20 × BMI) + (0.23 × Age) − (10.8 × Sex) − 5.4. However, this is ±5-6% accuracy — less precise than circumference methods.

How often should I measure body fat percentage?

Every 4-6 weeks is ideal. Body fat changes slowly — measuring more frequently introduces too much noise from hydration, time of day, and food. Always measure under the same conditions (morning, fasted, after bathroom).

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Medically Reviewed By

Dr. Sarah Jenkins, RD — Clinical Dietitian & Body Composition Specialist

Dr. Jenkins has 15+ years of experience in clinical nutrition and metabolic health.

Published: July 2026  |  Sources: US Navy Body Fat Validation Study  ·  Deurenberg BMI-Body Fat Formula