Calculate body fat from a tape measure or a progress photo, then track the change with honest ranges. Datum measures your silhouette on your phone, shows body fat as a range with the method behind it, and tells you when a change is real and when it is just noise. It is a fitness tracking tool for adults, not a medical device, and it never rates or ranks a body.
YOUR FIRST CHECK-IN IS FREE • A guided check-in: your phone's level, your framing, the light and your arms are checked before the shutter, and every photo that is refused says why. Your last check-in hangs over the camera as a ghost, to help your photos line up • A complete first result: waist to height, shoulders to waist, BMI, a body-fat estimate shown as a range with its method, and a plan with calories and protein • Anchor it: enter one DEXA, caliper or smart-scale reading you trust and Datum shifts its estimate to match, then shows how far off it might be • Apple Health (read only): fills in your height, weight, date of birth, sex, waist and body fat, so you do not have to type them • A body fat calculator that works without AI: decline the upload and Datum still measures your silhouette and, with a tape reading, uses the standard equations • Your photo timeline, a Learn guide on how body fat is estimated and how wrong it can be, and a sample timeline of a fictional person • Works in airplane mode, except the optional AI reading. No account, no ads, no tracking
DATUM PRO • Every check-in after the first: measurements, body-fat range and plan • Progress: a smoothed trend that shows the measurement noise, so a change is called a change only when it is bigger than the noise, and a before-and-after slider with the datum line to compare against • A plan that updates with your trend: maintenance calories, a deficit or surplus, and a protein target from your lean mass (estimates, with guard rails) • A PDF report of any check-in
HONEST ABOUT ACCURACY A photo cannot read body fat exactly. Any estimate, from any app, can be several percentage points away from a DEXA scan. That is why Datum shows a range, why you can calibrate it to a reading you trust, and why the trend over several check-ins matters more than any single number. There is no physique score, no ranking and no ideal body here.
PRIVATE BY DESIGN Your photos, measurements and weight stay on your iPhone. If you choose the optional AI reading, Datum first crops the photo from the neck down on your phone, so your face is never sent, and shares that one photo with our AI service on Google Cloud to produce an estimate. It is not stored or logged, and you can turn it off in Settings.
SUBSCRIPTION Datum Pro is a monthly auto-renewing subscription. Its price, in your currency, is shown in the app before you subscribe. Payment is charged to your Apple Account when you confirm the purchase. The subscription renews automatically unless you cancel it at least 24 hours before the end of the current period. You can manage or cancel it in your Apple Account settings. If it ends, your check-ins stay on your phone and their results lock until you subscribe again; your first check-in's result stays unlocked.
Datum is for adults (18 and over). It is not a medical device and does not diagnose anything. If you are pregnant, have a medical condition, or tracking your body affects how you feel about food, talk to a clinician first.
Terms of Use: https://www.aurorapps.com/terms/datum Privacy Policy: https://www.aurorapps.com/privacy/datum
App Details
- Category: Health & Fitness
- Age Rating: 9+
- Version: 1.0
- Price: Free to download, with an optional Datum Pro (monthly) (see the App Store for pricing)
Key Features
- A guided check-in checks level, framing, light and arms before the shutter, says why it refuses a photo, and shows your last one as a ghost
- Your first full result is free: waist-to-height, shoulder-to-waist, a body-fat estimate shown as a range with its method, and a plan
- Anchor it: enter one DEXA, smart-scale or tape reading you trust and Datum shifts its estimate to match, then shows how far off it might be
- Works without AI: decline the upload and Datum still measures your silhouette and, with a tape reading, estimates body fat with the standard equations
- BMI and waist-to-height side by side, so you can see why the scale and the mirror disagree
- Your photo timeline and a Learn guide on how body fat is estimated and how wrong it can be. No account, no ads, no tracking
Premium Features
- Every check-in after the first: measurements, body-fat range and plan
- Progress: a smoothed trend that shows the measurement noise, and a before-and-after slider
- A plan that updates with your trend: maintenance calories, deficit or surplus and a protein target from lean mass (estimates)
- A PDF report of any check-in
Privacy First
Datum: Body Fat Calculator sends some information off your iPhone, only as described in the privacy policy. There are no accounts, ads or tracking. The App sends one anonymous install message the first time it is opened. See our Privacy Policy for details.
Compatibility
- iPhone: Requires iOS 17.0 or later
Legal Information
For information about how we handle your data and your rights, please read our Privacy Policy.
For terms of use and licensing information, please read our Terms and Conditions.
- Privacy Policy URL: https://www.aurorapps.com/privacy/datum
- Terms of Use URL: https://www.aurorapps.com/terms/datum
- Support: support@aurorapps.com