Free AI Body Fat Calculator from a Photo
Upload one front or side photo in fitted clothing and Fat%AI returns an estimated body fat percentage, a category (Athletic / Fitness / Average), a confidence level, and how long it should take you to reach 10%, 12.5% and 15% body fat. Three scans a day are free, no signup required.
How AI body fat analysis works
- 1. Upload photo. Front or side view in fitted clothing.
- 2. AI analyzes. Gemini 3 Pro plus on-device pose detection examine body proportions, muscle definition and fat distribution.
- 3. Get results. Body fat percentage, category and goal timelines — shareable or emailed to you.
Body fat percentage chart
| Category | Men | Women |
|---|---|---|
| Essential Fat | 2-5% | 10-13% |
| Athletic | 6-13% | 14-20% |
| Fitness | 14-17% | 21-24% |
| Average | 18-24% | 25-31% |
| Above Average | 25%+ | 32%+ |
Frequently asked questions
How accurate is AI body fat estimation from a photo?
It is an estimate, not a measurement — a photo-based reading can be off by several percentage points, so use it to follow a trend rather than as an exact figure. For the most consistent results use good lighting, stand straight, wear fitted clothing and repeat the same pose each time.
How does AI estimate body fat from a photo?
A vision AI model (Gemini 3.1 Pro) reads visible muscle definition, fat distribution and body proportions from your photo, combined with distance-invariant body proportions measured on your device so camera distance does not skew the result.
What body fat percentage is considered athletic?
For men: 6-13% is Athletic, 14-17% is Fitness, 18-24% is Average. For women: 14-20% is Athletic, 21-24% is Fitness, 25-31% is Average. Essential fat minimum is 3-5% for men and 10-13% for women.
How long does it take to go from 20% to 10% body fat?
Losing 10% body fat takes approximately 20-30 weeks (5-7 months) at a safe rate of 0.5-0.75% per week. The last 2-3% takes longer as your body becomes leaner.
Is this body fat calculator really free?
Yes. You get 3 free AI body fat scans with no signup required. For unlimited scans plus full progress tracking, body measurements and weekly reports, sign up for the full app.
Related reading: How AI estimates body fat from a photo · How to take progress photos for an accurate reading · Body fat percentage chart for men and women
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