Body fat from one photo — analyzed once, then deleted. Here's how I built it.

Realbodyfat — Tue, 25 Aug 2026 21:55:41 +0000

I kept wanting a number between "guess in the mirror" and "book a $150 DEXA scan." Calipers need a second person and a steady hand. Smart scales swing a few points depending on how much water you drank. So I built an AI body-fat scan from one photo: upload one full-body photo, get body fat %, lean mass and fat mass in about ten seconds.

The constraint that shaped the whole thing: the photo is analyzed once and discarded. No account, so there's no row to attach it to. Nothing is written to disk, and nothing is used for training. That turned out to drive most of the architecture.

The stack

Astro on Cloudflare Workers. The marketing pages, the free US Navy tape calculator, and ~190 programmatic pages (body-fat-by-waist, Army max-waist by height, method comparisons) are static and served from the edge. The photo scan is the only dynamic part.
A single React island for the scan flow — image picker, the request, the result card. The rest of the site ships zero JS.
Durable Objects for credit wallets. No user accounts, but people who buy a credit pack need their credits to persist. A license code maps to a Durable Object that holds the balance. It's the smallest stateful thing I could get away with, and it means there's no user table to leak.
A vision model behind a Worker does the estimate. The image goes straight through — Worker → model → result — and is never persisted at either end.

The honest part

It's an estimate, not a measurement, and the site says so on every page. DEXA is better and I say that too. Photo-based estimation is weakest at the extremes (very lean or very muscular bodies), and depends on photo quality. The Navy tape method — also free and unlimited on the site — lands within about 3–4 points of DEXA for typical builds if you'd rather use a tape than a camera. The move I recommend is to pick one method and track the trend over weeks, not to trust any single reading.

Pricing, because someone always asks

One free scan a day, no account. After that it's a one-time credit pack — no subscription, and credits never expire. Each scan costs me inference, so the free tier covers casual tracking and packs cover people who want more.

What I'd do differently

Going account-less made the credit system the hardest part, not the ML. If I started over I'd design the license-code → wallet flow first and build the rest around it, instead of bolting statefulness onto a deliberately stateless site.

Happy to answer anything about the edge setup, the zero-retention design, or where the estimate falls over. Try it: the free body fat calculator.

Real Body Fat: Your body fat, in one photo.

Realbodyfat — Sat, 22 Aug 2026 21:39:47 +0000

Estimating body composition usually requires expensive clinic visits or inaccurate smart scales. Real Body Fat is a new web-based AI tool that estimates body fat percentage, lean mass, and fat mass from a single full-body photo—along with your age, height, and weight.

It's designed as a fast, accessible fitness estimate for training and tracking, minus the clinic.

✨ Key Features

AI Photo Analysis: Get your body fat %, lean mass, and fat mass in seconds from one photo.
Zero-Retention Guarantee: Photos are analyzed once in real-time. They are never stored and never used for training AI models.
Frictionless Entry: 1 free scan a day with absolutely no account or sign-up required.
Free Alternative: A free, unlimited US Navy circumference (tape-method) calculator sits alongside the AI tool.
Honest Limitations: We state our limits clearly on the page (e.g., DEXA is better for clinical accuracy, and very lean bodies may read high).

💳 Pricing & Platform

We hate subscription fatigue. Real Body Fat uses a straightforward freemium model:

Free Tier: 1 free AI scan per day.
Credit Packs: One-time credit packs starting at $5 for 10 scans, or $15 for unlimited. Credits never expire.
Zero Subscriptions.
Platform: Web (optimized for both mobile and desktop browsers).

Whether you're tracking your cutting phase or just curious about your baseline, try it out and let us know what you think!

Try it here: Real Body Fat
Launched: August 2026 | Support: realbodyfat.com@gmail.com

DEV Community: Realbodyfat