Why I built When2DriveSober

As someone who likes a good beer and visiting pubs, I wanted an app that could track drinks and show the effect they have over time. I found that most alcohol calculators focused on a single number and felt rather mathematical and scientific to use. So I built this app to make recording drinks quick and easy, using a visual timeline to show how blood alcohol levels may rise and fall—without feeling overly technical, which is often the last thing you want after you've had a few drinks.

The main purpose is to help people understand how the body processes alcohol and why someone may feel perfectly fine to drive while still being over the legal limit or unsafe to drive. I also wanted to include practical features that many other apps don't offer, such as comparing two people so you can see how their estimated alcohol levels differ over time.

The app is intentionally safety-first. It should never be used to decide that someone is legally or medically fit to drive. Its purpose is to help people understand risk and avoid false confidence.

Part of Travel Tools & Tips

This app is one of several small tools and apps I have created as a personal side project, I have been building a range of useful utility apps which I have made available for free through the Travel Tools & Tips website.

The wider project includes apps and tools related to travel planning, comparisons, international trips and everyday decision‑making.

Most of the apps I build for this project come from personal experiences where a small utility app can help solve a real‑world problem and make everyday life a little easier.

Professional background

My day job is working in product design and digital product development as Head of Product Design at BroadShield, a UK-based company focused on workforce development software.

Projects like When2DriveSober are personal side projects created independently in my own time. They give me a way to experiment, learn and build small focused tools from start to finish.

Important note

When2DriveSober and the other apps on Travel Tools & Tips are personal side projects. They are not products of BroadShield, and BroadShield is not responsible for the content, tools or services published on this website.

Free to download apps with no hidden fees

This app has been built as a personal fun project in my own free time to solve a task that I have personally wanted an app for.

I sometimes compare building apps to Lego for grown‑ups as I enjoy the process of building an app up from just an idea, so often when I want an app for something - I've used this as a personal challenge to have some fun building my own app.

In my professional work, we have dedicated teams covering areas such as IT and infrastructure, whereas this project allows me to get back to basics and learn by doing handling everything myself, at my own pace and without any commercial pressures or deadlines.

My focus on this project is to have fun building apps, and hopefully get good reviews and feedback. I want to keep this project a non commercial hobby project, which is why I plan to keep free versions of my apps available to download. Some parts of the website or app may include adverts, but this is mainly to help cover costs such as hosting, development and app store fees.

That same philosophy shapes the wider Travel Tools & Tips project; creating free useful travel and utility tools that are well designed, easy to use and give a good user experience. So I genuinely welcome feedback — both good and bad — to learn what works and what doesn't and help the app evolve and improve over time.

Safety-first philosophy

The app is deliberately cautious. If a drink strength range is selected, the higher value is used. Food slows absorption in the estimate, but does not remove alcohol. Green or “near zero” states must never be treated as proof that driving is safe or legal.

The guiding principle is simple: it is better to slightly overestimate risk than underestimate it.