This is a question that recently came to me while standing in front of a urinal.

How many urinals should equal one toilet?

Let me explain more clearly. In public places where there are restrooms there are usually both men’s and women’s facilities of equal capacity. Now, the men’s facility has a mix of both urinals and stalls, while the women’s facility has only stalls. How many additional stalls will the women’s facility have for each urinal in the men’s bathroom?

Now there are a couple considerations. Obviously, urinals take up less room, so in a given square footage, a greater number of urinals can be fit. However, a designer presumably should be trying to equalize flow of people through both facilities, so there should be additional stalls in the women’s facility to make up for the quicker speed of the urinal. So what’s the magic ratio? How many urinals per stall?

Another way to think of this question might be to imagine just a men’s restroom being designed. How many urinals and stalls does the designer put in to achieve an optimum flow of people through the restroom? Obviously, at least one stall is necessary. Starting from the assumption of one stall and a large number of urinals. How many urinals are removed for each additional toilet added?

Ponder away, but it’d be really amazing if someone would conduct some experiments to find out an answer.