You’ve been to a work do or a birthday party and had a few beers or a few glasses of wine. You’re a bit unsteady on your feet, and not really sure whether you’re OK to drive.

This amazing tool allows you to check your blood-alcohol levels yourself – instead of waiting for the traffic police to do so.

(And don’t be shy to call a taxi if you’re over the limit – it’s a lot less hassle than spending the night in a cell.)

The legal blood alcohol limit in South Africa is 0.05g per 100ml of blood.

Type of drink	Beer Wine Cocktail-Spirits
Your gender	Female Male
Number of drinks
Your weight (kg)
Drinking duration (hrs)
Blood alcohol content	g per 100 ml