Ok to drive

Maarten Labs

Contains adsIn-app purchases

About this app

Know your limit. Own your night.
We use a medically-informed algorithm — designed alongside doctors — to estimate your Blood Alcohol Content (BAC) in real time, based on your weight, gender, drinks consumed, food intake and fatigue.

How it works
Enter what you're drinking and we do the math. Your BAC updates as the night progresses, giving you a clear picture of where you stand — green, yellow, or red.

What is BAC?
Blood Alcohol Content is the percentage of alcohol in your bloodstream. It peaks 30–70 minutes after drinking. Despite what you've heard, nothing lowers BAC except time — not coffee, not cold showers, not water. We'll tell you exactly when you're clear.

What you get
- Real-time BAC tracking with a traffic light system
- Notifications when you're fit to drive again
- Hydration reminders to stay ahead of the hangover
- Hangover predictions so you know what tomorrow looks like
- Multiple user profiles — track the whole group
- A calendar view of your drinking habits over time
- A home screen widget so your BAC is always one glance away
- A full drink library plus custom drink builder

A word of honesty
Everyone metabolizes alcohol differently. This app gives you a well-informed estimate — not a guarantee. Never use it as the sole basis for deciding to drive.
I built this because I believe people make better choices when they have better information. Consider this your smarter drinking companion, not a substitute for medical advice.

What’s new

Introducing Dark Mode
Enjoy a sleek, easy-on-the-eyes experience anytime, anywhere.