The other week I was out teaching my son to parallel park. He asked the reasonable question, “If you’re parking between two cars, how do you know if you have enough room?”

I responded that you just sort of get a feel for it with practice, and that when driving big trucks like mine, often you just don’t. Silly me. It turns out there’s an equation for figuring out this very thing. Just crunch the formula below and it will yield the incremental distance you need over the length of your vehicle in order to park in the spot.

Of course, this assumes you’ve already taken some careful measurements of the car you are driving so that you know the radius of the car’s turning circle and such. But the clever math whiz will simplify the equation by plugging all that data in ahead of time. In that case, you only need to hop out, measure the width of the car you’re parking behind and the length of the open spot. Hop in, do one square, one square root, and a little arithmetic, and you’re ready to park!

Granted, by then the store you were heading to would have closed, or some cute girl in a Kia would have slipped into the spot you were eying up. So in the end, while this is interesting, it’s not too useful other than being something Kim can roll her eyes about.