Ratio - Body Fat by Photo
Estimate body fat by photo
Only for iPhone
Free · In‑App Purchases · Designed for iPhone. Not verified for macOS.
iPhone
Snap one photo and get your body fat percentage, FFMI, lean mass and BMR in seconds. Built for lifters who track progress, not guesswork. Start your free week.
Ratio estimates your body fat percentage from a single photo — no calipers, no gadgets, no guessing.
Your body is the most honest reference you have. Ratio reads it and turns it into the numbers that actually matter for training.
HOW IT WORKS
1. Set up once: sex, age, height.
2. Take one front photo, abs braced. Already have a gym photo? Just upload it.
3. Get your full body composition breakdown in seconds.
Add optional photos (relaxed front, side profile) for a sharper estimate.
WHAT YOU GET
• Body fat % — one clear number, front and center
• FFMI — the index that actually reflects how muscular you are
• Lean mass and fat mass in kg — your weight, broken down
• BMR — resting energy expenditure via Katch-McArdle, based on lean mass rather than total weight
Every number comes with a visual gauge and a plain comparison line, so you instantly know where you stand.
TRACK YOUR PROGRESS
Ratio saves every estimate. Browse your history and compare any two dates side by side to see how your physique is actually changing over time.
BUILT FOR LIFTERS
Ratio is made for people who already train and care about progress. Weight pulls automatically from Apple Health when available, so every estimate stays up to date.
MEMBERSHIP
Ratio Premium is an auto-renewable subscription, offered as a monthly or a yearly plan, and it starts with a free 1-week trial. Payment is charged to your Apple Account at confirmation of purchase. The subscription renews automatically unless it is canceled at least 24 hours before the end of the current period, and your Apple Account is charged for the renewal within the 24 hours before the current period ends. You can manage or cancel your subscription in your Apple Account settings. Any unused portion of a free trial is forfeited when you purchase a subscription.
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Ratio provides estimates for informational and fitness purposes only. It is not a medical device, it takes no physical or clinical measurement, and it does not provide medical advice, diagnosis, or treatment. Seek a doctor's advice in addition to using this app, and before making any medical decisions. Every number shows its formula and its sources in the app (Account → Method & sources).
Terms of Use (EULA): https://www.apple.com/legal/internet-services/itunes/dev/stdeula/
Privacy Policy: https://ratio-coral.vercel.app/privacy
Ratings & Reviews
- This app hasn’t received enough ratings or reviews to display an overview.
The developer, Kompa, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
Data Linked to You
The following data may be collected and linked to your identity:
- Health & Fitness
- Purchases
- Contact Info
- User Content
- Identifiers
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
Information
- Seller
- Kompa
- Size
- 72.1 MB
- Category
- Health & Fitness
- Compatibility
Requires iOS 16.4 or later.
- iPhone
Requires iOS 16.4 or later. - Mac
Requires macOS 12.0 or later and a Mac with Apple M1 chip or later. - Apple Vision
Requires visionOS 1.0 or later.
- iPhone
- Languages
- English and French
- Age Rating
9+
- 9+
- Contains
Health or Wellness Topics
- In-App Purchases
Yes
- Yearly $44.99
- Monthly $8.99
- Copyright
- © 2026 Kompa
