Contact Us

Have a question, found a bug, or want to suggest a feature? We'd love to hear from you.

Get in Touch

The best way to reach us is by email. Send your message to:

Please include a clear subject line so we can route your message appropriately. We read every message and aim to respond within 48-72 hours.

Before You Contact Us

You might find your answer here. These are the most common questions we receive:

"Is this calculator accurate?"

The calculator uses established formulas that are widely accepted in sports science and nutrition research, including the Boer formula for LBM estimation, the U.S. Navy method for body fat calculation, and the Martin Berkhan formula for muscle potential. These formulas provide reasonable estimates for most people, typically within 2-5% of laboratory measurements. However, they are estimates—not precise measurements. For the most accurate body composition data, consider a DEXA scan or hydrostatic weighing. Our About page explains our methodology in detail.

"Can I use this calculator on my website?"

Linking: You are welcome to link to any page on this site. No permission needed—just link directly to leanbodymasscalculator.org or any specific calculator tab.

Embedding: If you want to embed the calculator in an iframe or integrate it into your own site, please contact us first to discuss. We're generally open to partnerships with fitness, health, and educational sites, but we need to ensure proper attribution and quality of implementation.

Copying: Please do not copy our content, design, or substantial portions of the site. The mathematical formulas themselves are public domain, but our implementation, text, and design are protected.

"I found a bug"

Thank you for helping us improve! To help us fix the issue quickly, please include:

Browser and version (e.g., Chrome 120, Safari 17, Firefox 121)
Device type (e.g., iPhone 14, Windows laptop, Android tablet)
Steps to reproduce — What inputs did you enter? What did you click?
What happened — Describe the incorrect behavior
What you expected — What should have happened instead?
Screenshots — If possible, attach a screenshot showing the issue

"I have a feature request"

We welcome suggestions for new features, additional calculator tabs, or improvements to existing functionality. Many features in this calculator came from user suggestions. When submitting a feature request, it helps to explain:

What you're trying to accomplish
How you currently work around the limitation (if applicable)
How the feature would help you or others

We can't implement every suggestion, but we carefully consider each one and prioritize based on how many users would benefit.

Feedback Welcome

Beyond bug reports and feature requests, we genuinely appreciate all feedback:

Usability feedback: Is something confusing? Hard to find? Let us know.
Accuracy corrections: If you believe a formula is implemented incorrectly or have more accurate reference data, we want to hear about it.
Content suggestions: Topics you'd like us to cover in our guides, questions you think should be in the FAQ.
General impressions: What do you like? What could be better? How did you find us?

Your input helps us make this tool more useful for everyone. Thank you for taking the time to reach out.

Measurement Help Quick Reference

Getting accurate measurements is the most important factor for reliable results from the LBM Calculator. Use this table as a quick guide when taking measurements for the Navy Method. For detailed instructions, see our LBM formula guide.

Body Part	Where to Measure	Tips	Common Mistakes
Neck	Narrowest point below Adam's apple	Keep tape horizontal, don't flex	Measuring too high or too tight
Waist	At navel level, standing relaxed	Exhale normally, don't suck in	Measuring at belt line instead
Hip (Women)	Widest point of buttocks	Stand with feet together	Measuring too high or too low
Wrist	Narrowest point below wrist bone	For frame size calculation	Including the wrist bone
Ankle	Narrowest point above ankle bone	For frame size calculation	Measuring over clothing

Pro Tip: Take each measurement 3 times and use the average. Measure in the morning before eating for the most consistent results. A 1-inch error in waist measurement can shift your body fat estimate by 2-3%.

Helpful Resources

Before reaching out, these resources may answer your question:

Our Tools & Guides

LBM Calculator — Calculate your lean body mass, body composition, muscle potential, and protein needs
About Our Methodology — The science behind every formula we use
LBM Formula Guide — How Boer, James, Hume, and Navy formulas work
LBM Chart — Reference ranges by height and gender
LBM for Women — Female-specific body composition guidelines
Muscle Mass Calculator Guide — Estimating skeletal muscle mass
BMI for Muscular People — Why BMI fails for athletes
Maximum Muscle Potential — Your genetic building ceiling
Protein Based on LBM — Optimal protein intake by goal
Ideal Lean Body Mass — Target LBM for different goals
How to Increase LBM — Strategies for building lean mass
Body Fat vs Lean Mass — Understanding the difference

External Resources

For professional body composition assessment or personalized guidance:

DEXA Scan Information (NIH) — Learn about the gold standard for body composition measurement
Find an ACSM Certified Professional — Locate certified exercise physiologists and personal trainers near you