Alcophone - BAC calculator that gets your body right — and gets you home
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Alcophone estimates your blood alcohol content with peer-reviewed body-composition models (Norberg/Deurenberg, 2003) instead of the 1932 Widmark formula most apps still use — which can underestimate BAC by up to 25%. Log from 5,800+ real drinks with real ABV and serving sizes, factor in meals and water, see exactly when you'll be sober, and check the legal limit for your state or country. The moment your BAC is above zero, a rideshare button is on screen. No account, no server, works offline.
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Hi Product Hunt 👋 I'm the one person behind Alcophone, and today is the first time I'm showing it to people who aren't my testers. Slightly terrified. Mostly excited.
The idea came from a party. A friend of mine got unwell from drinking too much — he'd been trying to quit for months and was tracking his consumption with Alcodroid. After that night I opened every BAC calculator on the Play Store and found the same thing under the hood: a formula from 1932. Nineteen. Thirty. Two. It only knows your weight, so a lean person and someone with high body fat, same weight, get the exact same number. For the second person it can be off by 25%, and always in the dangerous direction. That bothered me more than I expected.
So I started reading the pharmacokinetics papers. The better model has existed since 2003 (Norberg): alcohol distributes into fat-free mass, not total body weight. Nobody had put it in an app, so I spent about a year of evenings doing that. The scope grew along the way: 5,800 drinks with their actual ABV and serving sizes, because a pint of 8% IPA is not "one drink"; a food and water input, because a full stomach can cut peak BAC by a third or more and the other apps ignore it; legal limits for every US state, Canadian province, Australian state, the UK and India; and 10,000+ tests, mostly around the boundary cases (what day does a drink at 2 AM belong to?).
The part I care about most isn't the math, though. It's what happens after the number: as soon as your BAC is above zero, the ride-home button is right there, and at dangerous levels one tap calls emergency services. The app never tells you it's fine to drive. It's built to do the opposite. I wish my friend had had it that night.
To be clear, it's still an estimate. A breathalyzer measures; this calculates from what you tell it, and food alone can move the result a lot. What I can say is that the model is the best one in the literature, the error runs in the safer direction, and everything stays on your phone — no account, no server, works offline.
Free with ads on Android. A one-time premium unlock (no subscription, I hate those too) adds a more personalized calculation. iOS is next.
I'll be around all day. Ask me anything — the formulas, the drink database, the 4 AM "drinking day" boundary that cost me a weekend. And if you've ever had that "wait, am I OK to drive?" moment: this is for that moment.