By Dr. Andreas Boettcher, D.C., Functional Medicine, B.S. Health/Exercise Science

3x Ironman Triathlete, Master's Men's Physique Competitor & Medication FREE at 55

www.ItsOnlyHalftime.com

IOH Body Fat Calculator: Measure What Actually Matters (Not Just the Scale)

When most guys step on the scale, they’re looking for one number.

The problem?

That number tells you almost nothing about what truly matters for performance, health span, and hormonal optimization.

Two men can both weigh 200 pounds:

• One is 12% body fat with dense muscle, strong bones, and a resilient cardiovascular system.

• The other is 30% body fat with higher visceral fat, lower testosterone, and elevated cardio metabolic risk.

Same weight. Completely different physiology.

That’s why, insideIt’s Only Halftime, we focus on body composition—how much of you is fat mass vs. lean mass (muscle, bone, organs, connective tissue)—not just “weight loss.”

The IOH Body Fat Calculator is designed to help you do exactly that, using two evidence-based methods:

1. A tape-measure method based on the U.S. Navy circumference equations.

2. A skinfold caliper method using the Jackson–Pollock 3-site equations combined with the Siri formula to estimate body fat from body density.

Use one or both, then track trends over time as you move through the IOH Peak Performance Protocol.

What Is Body Fat (and Why You Actually Need Some)

Body fat isn’t the enemy. It’s a metabolically active tissue with critical roles in:

• Hormone production (including sex hormones and leptin)

• Temperature regulation

• Organ cushioning and structural support

• Serving as a fuel reserve when energy intake is low

We generally talk about two main categories:

• Essential fat– The minimum fat your body needs to stay alive and function properly (hormones, brain, nerves, cell membranes).

• Storage fat– The extra energy reserve stored in adipose tissue under the skin (subcutaneous) and around organs (visceral).

Problems show up when storage fat—especially visceral fat—climbs beyond a healthy range. That’s when risks climb for:

• Cardiovascular disease

• Insulin resistance and type 2 diabetes

• Systemic inflammation and oxidative stress

• Hormonal disruption, including lower testosterone in men

The goal in IOH isn’t to be “as lean as possible at any cost.”
It’s to land in the sweet spot where:

• You’re lean enough for strong metabolic and hormonal health.

• You’re fueled enough to build and maintain muscle.

• You can perform in the gym, on the course, and in life—without breaking your physiology.

Healthy Body Fat Ranges (Big Picture)

Exact “ideal” body fat targets depend on:

• Age

• Sex

• Training background

• Genetics and bone structure

But for most adults, typical functional ranges look like this:

• Men: roughly 10–20% can represent a healthy, sustainable range. Ideally 10 -15% for the Peak Performance Man

• Women: roughly 18–25% is often considered a healthy range

Athletes and highly trained individuals may live on the lower end; more sedentary people drift higher. The key is less about a single perfect number and more about:

• Direction: Are you trending toward improved composition over time?

• Context: How do labs, strength, energy, sleep, libido, and HRV look alongside that number?

Inside IOH, we always pair body fat data with labs, performance, and symptoms, not just aesthetics.

How Body Fat Is Measured (From Lab-Grade to Living-Room)

There are many ways to estimate body fat. Some of the more advanced tools include:

• DEXA scans (Dual-Energy X-ray Absorptiometry)– Very detailed; provides bone density and regional fat distribution.

• Hydrostatic (underwater) weighing / Air-displacement (BodPod)– Use body density to estimate body fat.

• Bioelectrical impedance (BIA)– The typical “body fat scale” that sends a small current through the body; results vary with hydration status and many other factors.

These can be useful, but they’re not always accessible or consistent. For our purposes, we want:

• Affordable

• Repeatable

• Good enough to track trends over time

That’s why we focus on two field methods that can be done at home with simple tools and have solid research behind them:

1. Tape-measure / U.S. Navy method

2. Skinfold caliper method (Jackson–Pollock 3-site)

Method 1: Tape-Measure (Navy) Method

The tape-measure method estimates body fat using:

• Height

• Neck circumference

• Waist circumference (and hips for women)

These values are plugged into a logarithmic equation validated by the U.S. Navy for estimating body fat percentage.

Why the Tape Method Works

Fat tends to accumulate in relatively predictable patterns—especially around the abdomen, hips, and neck. Circumference changes at these sites correlate with changes in body fat for most people.

The IOH calculator uses these measurements, along with your height, to estimate:

• Body fat percentage

• Fat mass

• Lean mass

Pros

• Fast, simple, minimal equipment (just a soft tape)

• Easy to repeat under similar conditions

• Great for tracking changes week to week

Cons

• Built on population averages—less precise for very muscular, very lean, or unusually built individuals

• Sensitive to measurement technique and posture

• It’s an estimate—not a lab value

Method 2: Skinfold Caliper (Jackson–Pollock 3-Site) Method

The skinfold method uses a caliper to measure the thickness of a fold of skin and subcutaneous fat at specific locations.

The IOH calculator uses the Jackson–Pollock 3-site equations(different sites for men and women) to estimate body density, and then applies the Siri equation to convert density into body fat percentage.

Measurement Sites

For most adults, the 3-site protocol looks like this:

• Men (3-site):

  • Chest/pectoral

  • Abdomen

  • Thigh

• Women (3-site):

  • Triceps

  • Suprailiac (just above the hip bone)

  • Thigh

Each site is measured in millimeters, usually twice or three times, and the values are averaged.

Why the Skinfold Method Works

These formulas were developed by comparing skinfold measurements to more precise lab methods (like hydrostatic weighing) across many individuals. From there, equations were built that relate:

• Sum of skinfolds

• Age

• Sex

…to predicted body density. Siri’s equation then converts that density to body fat %.

When done correctly, skinfolds can be within about 3–5 percentage points of more advanced methods—good enough to guide training and nutrition for the vast majority of people.

Pros

• More sensitive to changes in subcutaneous fat

• Helpful for seeing where you’re losing fat (abdomen vs. thigh, etc.)

• Inexpensive once you own a caliper

Cons

• Requires practice and consistency to do well

• Someone else measuring you improves accuracy

• Can be less accurate for very lean or very obese individuals

I personally recommend the Sequoia Trimcal 4000 Body Fat Caliper with Tape Measure - Precision (Dual-Sided Design) for Fitness Tracking - Color Black & Black

Found on AMAZON HERE.

How to Get the Most Accurate Results at Home

Regardless of which method you use, consistency is everything.

For Tape Measurements

• Use a soft, flexible tape and keep it level around the body.

• Measure on the skin or with minimal, thin clothing.

• Pull the tape snug but not tight—do not compress the tissue.

• Stand upright, breathe out normally, and then take the measure (no sucking in).

• Take each site at least twice and use the average.

For Skinfold Calipers

• Always measure on the same side of the body (usually the right).

• Pinch the skin and underlying fat, not the muscle.

• Place the caliper about1 cm below your fingers, perpendicular to the fold.

• Avoid testing immediately after training or a large meal.

• Take 2–3 measurements per site and average the closest values.

Timing and Conditions

Whichever method you choose, try to:

• Measure at the same time of day (ideally morning, after using the restroom and before eating).

• Keep hydration, sleep, and prior activity as consistent as possible.

• Use the same method and protocol every time.

NOTE: If you do elect use technology instead, I recommend the HUME Scale. You can use this link for $20 off the purchase price.

How to Use the IOH Body Fat Calculator (Step-by-Step)

You can use either method alone, but many IOH clients like to use both and compare.

1. Choose Your Method(s)

• If you have a tape only:Use theTape / Navy Method.

• If you have a caliper and a partner (or are comfortable self-measuring): Use the Skinfold Method.

• If you’re serious about tracking composition through your protocol: Use both and look for convergence and trends.

2. Enter Your Basic Data

For both methods, you’ll typically enter:

• Sex

• Age

• Weight (lbs or kg)

• Height (for tape method)

This allows the formulas to convert percentages into fat mass and lean mass, which is often more meaningful than the percentage alone.

3. Take Your Measurements

Follow the technique guidelines above and input:

• Tape method:

  • Waist, neck, and hip (for women) circumferences

• Skinfold method:

  • Three caliper sites depending on your sex

4. Review Your Results

The IOH calculator will provide:

• Body Fat %– What portion of your body mass is fat

• Fat Mass– How many pounds/kilos of that weight are fat

• Lean Mass– Everything else: muscle, bone, organs, connective tissue, water

Most importantly: don’t obsess over a single reading.

Focus on trends over weeks and months as you apply the IOH Peak Performance Protocol (nutrition, training, sleep, stress management, and lab-driven optimization).

The IOH Perspective: From Numbers to Strategy

A body fat number by itself is just data.

InsideIt’s Only Halftime, we plug that data into a bigger framework:

• Labs: Hormones, inflammation, insulin sensitivity, lipids, micronutrients

• Performance: Strength progression, conditioning, HRV, recovery

• Subjective state: Energy, focus, mood, libido, resilience

From there, we can make targeted decisions:

• Do we need more muscle gain while holding body fat steady?

• Do we need a fat-loss phase without crashing testosterone or thyroid?

• Is it time to shift macros, training volume, or recovery based on how your body is responding?

The body fat calculator is just one part of your Peak Performance Dashboard—a tool to help you make better decisions, not a verdict on your worth.

Final Word: It’s Only Halftime

If you’re reading this, chances are you’re not chasing a 6-pack for Instagram.

You’re a high-performing man in his “second half” who wants:

• A powerful, capable body

• Strong, optimized hormones

• A long health span free of pharmaceutical dependency

• The ability to show up fully—in your business, your relationships, and your life

Knowing your body fat, your lean mass, and how they change over time is one of the simplest, most potent ways to stay accountable to that mission.

That’s why we built the IOH Body Fat Calculator—and why we pair these numbers with advanced labs, personalized protocols, and a community of men refusing to accept decline as “normal.”

It’s only halftime.
The second half is where we finish the game.

⚡️ Ready To Declare It's Only Halftime® With the Most Comprehensive Natural Approach to Mens Health?

If you’d like to go deeper — to uncover the root causes behind your energy, hormones, metabolism, and performance — I invite you to book a complimentary consultation.

Together, we’ll review your health history and goals and determine if our Peak Performance Protocol based on your lab analysis, genetics, and lifestyle data is right for you!

👉Click here to schedule your complimentary consultation.

To learn more about our approach and success stories, visit www.ItsOnlyHalftime.com where we help men like you turn your second half into your best half naturally!

Finish Strong,

Dr. Andreas

Still Kickin' A** Medication Free at 55 Despite What the "Narrative" and what traditional doctors wanted me to believe!

Medical Disclaimer:

The information provided in this article is for educational and informational purposes only and is not intended as medical advice. It should not replace professional consultation, diagnosis, or treatment. Always consult your healthcare provider before making any changes to your health regimen or lifestyle.