How is the level calculated?

Promilleni uses the Widmark formula with the Watson estimate of body water.

1. Alcohol. Grams = volume (ml) × ABV × 0.789.
2. Body water. Watson, in litres, from your profile:Men: 2.447 − 0.09516 × age + 0.1074 × height (cm) + 0.3362 × weight (kg)
   Women: −2.097 + 0.1069 × height (cm) + 0.2466 × weight (kg)
3. Rise per drink. 0.8 × grams ÷ body water, in ‰.
4. Absorption. Each drink is absorbed evenly over up to 40 minutes from the logged time, or from 20 minutes earlier when the Log drinks setting is When finished.
5. Elimination. The level falls at a steady rate set by Metabolism: 0.10, 0.15 or 0.20 ‰ per hour for men, 0.12, 0.17 or 0.22 for women. It never goes below zero.
6. Sober by. When the level reaches zero, rounded up to the next five minutes.

Example: one 0.33 L beer at 4.7 % adds 0.21 ‰ for an 80 kg, 180 cm, 30-year-old man, before elimination.

How accurate is the level?

The formulas above give an average. Your body water and how fast you eliminate alcohol differ from it, so the sober-by time is typically off by about a fifth. Food and medication change the real level too. Promilleni is not a medical device. Never use it to decide whether to drive.

Does Promilleni encourage drinking?

No. Promilleni helps you keep track of what you drink, not drink more. Drink in moderation, and never drive after drinking. If you're worried about your own or someone else's drinking, AddictionLink offers free and anonymous self-tests, information and help.

Which devices are supported?

Apple Watch with watchOS 26 or later. Apple lists the watches that can run watchOS 26 on its Apple Watch models page. Promilleni runs on the watch alone and needs no iPhone app.

Why does Promilleni ask for Health access?

It reads your sex, date of birth, height and weight to estimate how your body handles alcohol. You can enter them in the app instead. Writing drinks to Health is optional and off until you turn on Log to Health in the settings.

How do I change Health permissions?

Open the Health app on your iPhone, tap your profile picture, then Apps under Privacy, then Promilleni.

How do I delete my data?

Delete a drink by swiping it in the recent drinks list. Deleting the app removes everything it stores. Drinks written to Health are deleted in the Health app.

Still need help?

Email support@promilleni.app.