Over time, the various components that make up hot tubs covers degrade; becoming less and less effective at insulating the water in the hot tub as they do. For this reason, hot tub covers should be replaced every 4-5 years. Today we will review how to properly measure your cover to ensure that the new cover fits just as well as the original.
The Importance Of A Proper Fit For Your Hot Tub Cover
Ensuring that your new cover fits properly is key to its performance. An ill-fitting cover will not form a proper seal with the top lip of the hot tub. Without a proper seal, your hot tub cover will allow steam to escape from the hot tub. The heat loss associated with this will greatly reduce your hot tub’s energy efficiency and can cost you hundreds or even thousands of dollars in added heating costs over the course of the cover’s lifespan.
What You’ll Need
To measure for your replacement hot tub cover you’ll need:
- A tape measure
- A ruler
- A plain piece of paper
- A pen or marker
Measuring Length & Width
The first, and most basic, step of measuring for your new hot tub cover is to measure the length and width of your current cover. Simply measure your cover using your measuring tape and write down the dimensions in inches; rounding to the nearest 1/2″.
Standard Fold Or Opposite Fold?
By default, your cover will fold along its longest dimension. For example, a hot tub cover that is 80″ by 75″ will fold along the 80″ dimension; giving you two halves that are 40″ x 75″. This is called a “standard fold” cover. Some covers do fold along the short side of the cover, however. These are known as “opposite fold” covers. After measuring the length and width of the cover, you will want to double check the fold direction of the cover to ensure that the new cover folds the same way that your current cover does.
While your cover will fit fine on the hot tub no matter which way it folds, it will affect how the cover sits on your cover lifter. Double checking your covers fold direction will ensure that you don’t have to re-install your cover lifter to accommodate your new cover.
Note: To make everything easy later, we recommend sketching out your hot tub cover on a piece of paper and writing down its dimensions on the sketch, including the direction of the fold (with a dotted line to indicate the fold).
Corner Radius
Another important aspect to your new cover’s fit is its corner radius. If the corner radius of the new cover isn’t right, the cover won’t properly follow the corners of the hot tub. This will prevent the cover from forming a seal all the way around the hot tub.
To easily measure your cover’s corner radius we recommend tracing the corner of your current cover onto a piece of paper, including some of the straight sides on both ends of the corner. Put a ruler on one of the straight sides of the tracing so that it continues that line to the edge of the paper. Draw a dashed line to the edge of the paper, then repeat this process on the other side of the corner so that both dashed lines intersect one another at a 90 degree angle.
To get the corner radius of the cover, simply measure the dashed line from the point that the two dashed lines meet to where the dashed line breaks away from the solid line.

Skirt Length
While often overlooked, the “skirt length” of your hot tub cover is critical to its effectiveness. Skirt length refers to the width of the extra material that hangs down from the bottom edge of the cover. This material serves two purposes:
- It covers the acrylic lip of the hot tub so that only the cover and cabinet are visible when the cover is on the hot tub. This is purely aesthetic.
- It improves the seal created between the hot tub and the cover by providing a “friction fit” around the outer edge of the hot tub.
If the skirt length is too short, the cover will not form a proper seal. Too long and it may be difficult to pull the skirt over the outside edges of the hot tub.
To measure the skirt length for your new cover, simply measure the length of the skirt on your current cover. This measurement should be taken from the bottom edge of the cover to the bottom edge of the skirt.
Measuring The Straps
Hot tub covers come with locking straps on two ends of the cover. These straps serve two purposes:
They allow you to lock the cover to keep unwanted people from using the how tub.
They add a bit of downward pressure to either end of the cover; giving you a tighter seal around the lip of the hot tub.
Most hot tub manufacturers install their cover straps in a standard location, though some do customize their location and length to suit their cabinets or access panel location. For this reason, we recommend that you double check the location and length of your hot tub cover’s straps to ensure that they will properly snap into the clips already installed on your hot tub’s cabinet.
To properly measure the straps you will need to note both the length of the strap (from the bottom of the cover to the end of the clip) and how far in they’re located (measuring from the side edge of the cover to middle of the strap).
Wrapping Up
Measuring for a replacement hot tub cover can seem complicated, but if you know what you’re doing it’s actually quite quick and easy to do. Taking the time to ensure that your new cover fits as well as the old one is also very important to the overall energy efficiency of the cover. In fact, a well fitting cover can save you hundreds of dollars in energy costs over the life of the cover. If you still have any questions about how to measure your cover, or if you’re ready to order a new hot tub cover, give us a call.