Working on a home improvement project often involves a lot of measuring but most of us don’t carry a measuring tape in our pockets. So, what if you find a new piece of furniture or home improvement item while you’re out shopping but you’re not sure if it will fit in your home?

Thankfully, most of us carry a measuring tool on us, even if we don’t realize it. You just need to look in your wallet! Dollar bills are roughly six inches long. If you want to get technical, they’re 6.14 inches long, but that isn’t worth worrying about when you’re working with approximate measurements.

If you can remember that a dollar bill is around six inches (and two dollar bills laid end to end are about a foot long), you’ll have a measuring tool that will give you a rough idea of the size of an item. Often, that may be all you need.