Nightcap: BAC & Drink Tracker

Nightcap is a BAC calculator and drink tracker that estimates blood alcohol concentration across a night — for you, and for everyone else at the table.

Log what you drink and it draws a curve: where your level is now, where it peaked, and roughly when you should be clear. Add the people you're out with and you'll see all of it at once, each with their own line on the same chart.

WHAT IT DOES

• A live estimate that rises and falls. Nightcap models absorption and elimination rather than counting drinks, so the number moves the way a body does — climbing after a round, easing off between them.
• Everyone at once. Add someone in two taps, give them a color, and their curve joins the chart. Switch between people without losing anyone's night.
• A drink list that matches how you actually drink. Sixteen to start; edit any of them, add your own, hide what you never order. Half, regular and double pours.
• Standard drinks by country. A standard drink runs from 8 g to 20 g of alcohol depending on where you are, so Nightcap uses your country's definition and shows volumes in your own units.
• Cocktail recipes with the numbers attached — how it's made, and what it counts as.
• Know your limits: what a standard drink actually is, what does and doesn't sober someone up, and a short self-check.
• An optional reminder when you're estimated to be clear.
• Works offline, in dark or light.

MADE FOR A NIGHT OUT

A quiet one, a long dinner or a full party — Nightcap works as an alcohol calculator and standard drinks tracker for all of it, keeping a running estimate of where everyone is and roughly how long until they are sober again.

WHAT IT IS NOT

Nightcap is entertainment and education. It is not a breathalyzer and it is not a measuring instrument.

Every number is an estimate built from weight, body-water basis and the clock. Real blood alcohol also depends on what you ate, how fast you drank, your liver, your medication, and a dozen things no app can see. Two people who drank exactly the same thing can end up far apart.

So never use Nightcap — or any app — to decide whether you are fit to drive, to work, or to look after anyone. It will not tell you that, and it does not try to. There is deliberately no countdown to a legal limit anywhere in the app: a timer counting down to a threshold reads as a countdown to permission, and that is not something an estimate can give you. If you have been drinking, treat the answer as no.

YOUR NIGHT STAYS ON YOUR PHONE

Drinks, levels, names, body details and self-check answers are stored on your device and never leave it. There is no account and no server holding any of it. The app does send anonymous usage analytics — which screens are opened, which features are used — and it contains ads.

Drink responsibly, and look after the people you're out with.