KFA-Rechner

Estimate your body fat with a tape measure.

KFA-Rechner US-Navy-Methode works out your body fat percentage from height, weight and a few circumferences, using the classic US Navy formula (Hodgdon & Beckett 1984).

€5.99 one-time. No subscription, no in-app purchases.

  • App Storecoming soon
  • Google Playcoming soon

What you measure

Men and women measure at different points because the formulas differ. The measuring guide in the app shows in a picture where the tape goes.

Men

Neck
just below the larynx
Abdomen
at navel height, across the navel
Height
without shoes
Weight
in kg or pounds

Women

Neck
just below the larynx
Waist
narrowest point between lower ribs and navel
Hips
widest point
Height
without shoes
Weight
in kg or pounds

What you get

Body fat percentage, BMI and lean mass, right after you enter your numbers.

  • Your circumference in Apple Health

    On iPhone the app writes body fat, weight, BMI, lean mass and your abdomen or waist circumference to Apple Health. On Android, body fat, weight and lean mass go to Health Connect.

  • Your own history

    The app keeps your circumferences with the date, including the hip measurement that neither Apple Health nor Health Connect has a place for.

  • Your last numbers are already there

    Next time you open the app, you only enter what has changed.

  • German or English, centimetres or inches

    The app follows your device language and works in metric or imperial.

Your measurements stay with you.

No server, no account, no analytics. Calculating and storing happen on your device. The app writes to Apple Health or Health Connect only with your permission and reads nothing from them. The details are in the privacy policy.