About Us

Who We Are

Sixpacks.fit was founded in 2026 by a team of certified fitness professionals, medical experts, and developers who share a common frustration: most fitness calculators online are buried behind sign-up walls, monthly subscriptions, or designed to funnel you into expensive coaching programs.

We built Sixpacks.fit to be different. Every tool on this site is completely free. No accounts. No email captures. No credit cards. Just open the page, enter your numbers, and get your results — instantly, in your browser.

Our Mission

Our mission is straightforward: give everyone access to the same fitness calculation tools that professional coaches and trainers use, without charging a cent. We believe that knowing your body fat percentage, understanding your TDEE, and having a realistic timeline to visible abs shouldn't require paying for an app subscription or hiring a personal trainer.

Every calculator on Sixpacks.fit uses peer-reviewed, published formulas — the U.S. Navy body fat method, the Mifflin-St Jeor equation, and evidence-based protein intake guidelines from the International Society of Sports Nutrition. We don't guess. We cite our sources.

Our Team

Our content and tools are created and reviewed by credentialed professionals:

  • Alex Rivera, CSCS — Lead Content Creator. Certified Strength and Conditioning Specialist with 10+ years of coaching experience. Alex writes every blog post and designs every workout on this site.
  • Dr. Sarah Chen, MD — Medical Reviewer. Board-certified physician, Stanford alumna, and ACSM member. Dr. Chen reviews all health and body composition claims for medical accuracy.
  • Marcus Webb, RD — Nutrition Reviewer. Registered Dietitian with a Master's in Nutrition Science and a member of the Academy of Nutrition and Dietetics. Marcus reviews all nutrition and dietary recommendations.
  • David Kim — Lead Developer. The engineer who turns fitness science into working code that runs entirely in your browser.

Learn more about our credentials and backgrounds on our Meet the Team page.

How We Create Content

Every article published on Sixpacks.fit goes through a three-step process:

  1. Research & Writing — Alex Rivera writes each piece based on current peer-reviewed research from PubMed, journals like the Journal of Strength and Conditioning Research, and guidelines from organizations like ACSM and ISSN. We cite studies directly in the text.
  2. Medical Review — Dr. Sarah Chen reviews any content making health, body composition, or medical claims. Content that doesn't pass medical review doesn't get published.
  3. Nutrition Review — Marcus Webb, RD reviews all dietary recommendations, supplement claims, and calorie/macro guidance for nutritional accuracy.

Read our full process on the Editorial Policy page.

Privacy & Data

We take privacy seriously. Every calculator on Sixpacks.fit runs entirely in your browser using JavaScript. Your measurements — weight, body fat, activity level, age — never leave your device. We don't store, track, or transmit any personal data. No cookies. No analytics that identify you. No third-party trackers.

This isn't just an ethical choice — it's a competitive advantage. When your data never touches a server, it can't be leaked, sold, or subpoenaed. Your fitness journey is your business.

Why "Sixpacks.fit"?

Because a visible six-pack isn't about vanity — it's a reliable proxy for low body fat, disciplined nutrition, and consistent training. The goal isn't to look like a fitness model. The goal is to prove to yourself that you can set a body composition target, follow a science-backed plan, and achieve it. That's what our tools help you do.

Questions? Reach out through our Contact Us page. We respond to every message.