There aren’t commonly made adapters to switch between the sizes.

Unfortunately, metric and standard hoses and machines are not very compatible. Common sizes for these vacuums include 27mm, which is roughly equivalent to 1 inch, and 50mm, which is just shy of 2 inches.

Brands such as Festool, for instance, use metric sizes for their hoses. If you look at many different brands that produce Shop vacuums, you’re likely to see some other odd sizes that don’t fit with the ones we’ve already covered. Less commonly, you might also see 1½-inch hose, though it will generally include adapters to allow it to fit on more common vacuum ports. There are three main widths of hose that you’re most likely to deal with: 2½-inch, 1⅞-inch, and 1¼-inch. Part of the reason that Shop VAC hose sizing can be so confusing is that there are so many different diameters of Shop VAC hose available. What Are the Most Common Shop VAC Hose Diameters Since Shop VAC hose sizing can be a bit of a complicated issue, we’re going to take a closer look at the most common sizes, their compatibility, and the effect they have on vacuum performance. In fact, if your vacuum doesn’t seem to be performing up to par, the hose might even be to blame. While these hoses are interchangeable to a degree, there are going to be benefits and drawbacks to each diameter of vacuum hose. Are these hoses freely interchangeable? Does it even matter which hose you use?

Some vacuums might even come with two different sized hoses and an adapter. You might notice that different vacuums come with hoses of different sizes. Whether you’re in the market for a new Shop VAC or you’re upgrading an old one, the hose that’s attached to your vacuum will have a pronounced effect on its overall performance.

Shop vac inlet deflector