How to Measure a Hot Tub Cover That Will Fit Perfectly

In this post, we discuss the many ways to measure the size of a hot tub cover and some other considerations when buying a new one.

You may think that you've bought a good quality hot tub cover, but how do you know it is the right size for your hot tub? When purchasing a hot tub cover online, you need to check the measurements of your existing cover before choosing one if you are unsure how big your current cover is or if a hot tub cover will fit perfectly.

Measure a Hot Tub Cover the Easy Way

Hot tub covers are optional, although some hot tubs include hot tub covers as part of the package. If you bought one of these and want to replace the old cover, you only need to measure the old one. Just make sure the cover is not deformed or warped and that it fits snugly on your hot tub. Otherwise, you need to measure the hot tub itself. The same goes if you bought one that doesn't include a hot tub cover.

How to Measure a Hot Tub Cover Based on Hot Tub Type

how to measure a hot tub cover featured image

There are roughly four types of hot tubs available in the market. Let's go through each and determine how hot tub covers are measured. You're going to make some measurements, so grab your tape measure, pen, or pencil, and framing square or straight edge if your hot tub has rounded corners).

Classic Cabinet

This one is the easiest. Just measure the outermost part of the hot tub shell from end to end. The skirt extends just a little bit below the rim.

Cabinet with Top Rail

For this one, you will measure the length of the top rail from end to end. The skirt extends slightly below the rail.

In-ground Hot Tub

Measure the outermost part of the hot tub from end to end. You'll be OK with regular hot tub covers if it has a rim like an above-ground hot tub. For rimless hot tubs, you need a skirtless one and has an overhang of 3 inches on all sides (add 6 inches to the total length and width of the opening)

Round Wood Tub

These hot tubs are primarily rimless. Just get the diameter by measuring across the center of the hot tub from end to end. Skirt length is entirely up to you.

Key Takeaways: When measuring hot tub covers, record the measurements in inches, not feet. This way, you can round up to the nearest inch. It's perfectly fine for hot tub covers to be 1-2 inches bigger than to have poorly fitted ones, causing significant heat loss.

How to Deal with Corner Radius

Most probably, your hot tub will have rounded corners. Consider measuring the corner radius when buying a hot tub cover to ensure it fits perfectly well. To do this, you'll need a carpenter's square, or if you don't have one, a ruler and a straight edge will do.

how to deal with corner radius

Place the carpenter's square against the hot tub rim at the corner and start measuring where the curve of the hot tub corner first touches the square, or the ruler, if you're using a straight edge with a ruler. As a rule of thumb, the hot tub cover radius should be 1/2 inch smaller than your hot tub rim. In other words, if it measured 5-1/2 inches, write it down as 5 inches. This may sound counterintuitive, but a smaller radius corner means it can cover a slightly bigger area than a bigger radius corner.

Key Takeaways: When getting the corner radius, think smaller is bigger and vice versa. Hot tub covers with a smaller corner radius will fit a hot tub with a bigger corner radius but not the other way around.

Other Factors to Consider

Skirt Length

Hot tub covers typically have skirts hanging down their sides to cover the hot tub's rim. Most skirts extend 5 inches from the bottom edge of the hot tub cover. Others have 2 inches of skirt. In any case, it should cover the exposed lip of the shell by more than 0.5 to 1 inch. Choose a skirtless hot tub cover if it's a rimless in-ground hot tub.

Strap Length

Straps secure the hot tub cover and keep it sealed. They're about 9 inches long from the bottom of the hot tub cover and extend 2 inches from the skirt, not including the latch.


Finding the right hot tub cover that would fit your hot tub isn't so hard. Anyone can take measurements using simiple tools and by following the correct procedure shown in this article. With a perfectly sized hot tub cover, you can be sure your hot tub stays sealed and the water keeps warm and clean.