How to Measure Hot Tub and Spa Covers


Guide to Measuring Hot Tub and Spa Covers

This guide will help you measure hot tub and spa covers so that they will fit perfectly. Even if your hot tub manufacturer has your model on file, take the time to measure to be sure. We have seen too many customers be given the wrong hot tub dimensions.

Regardless of the shape of your spa, you should measure from lip to lip, or the outside dimension measure hot tub coversof the acrylic. After you have a lip to lip measurement you may add up to 1/2″ on both the length and width. This will give you a 1/2″ of play all around your spa cover.



Skirt Measurement

The skirt is the flap that hangs from the bottom of your cover. The skirt is really just cosmetic but if not measured correctly can cause some problems because if it is too long it will bunch and push your spa cover up. If you have a wood rail, as in the picture above, measure from the top of the wood rail to the top of your spa acrylic. You want to be a little short rather than long so the skirt does not bunch. If you do not have a wood rail then you want to measure from the top of the spa to the bottom of the spa lip and add 1/2″.

Measuring the Hot Tub Corner Radius

This is the one that makes everyone worried. As the diagram shows the easiest way to measure a radius is with a carpenter square. The dimension needed is from the start of the bend to the imaginary point of the square if the tub was actually square. Rule of thumb is smaller is safer than larger. The smaller the radius the more square the corner of the hot tub cover.

Square or Rectangle with a radius on four corners

To measure radius “C”: extend straight lines indicated in red by laying straightedges against the sides of the spa. Measure from point “Y” to point “Z”. 

Square Spa Covers

The square hot tub cover is the easiest cover to measure. Simply measure your outside lip to lip, and add 1/2″ to each dimension. The only other dimension you will need is the skirt length.

Rectangle Hot Tub Covers

This is the same technique as the square spa, but make sure you request the fold direction you require. Most companies will by default cut the longest of the two sides in half.

Square or Rectangle with Radius Corners

Follow the square and rectangle spa cover procedure and add the radius measurement.

Round Hot Tub Covers

It is simple to measure a cover for a round hot tub. You only need the lip to lip measurement. If your old cover is measurable just measure across the seam. Remember to add 1/2″ of play. The only other measurement needed is the skirt length.

Octagon Covers

For the octagon spa cover, measure from lip to lip and add 1/2″ of play. Also, measure one panel of the octagon from point to point. The only other measurement needed is the skirt length.

Ellipse or Special Shaped Covers

Most of these hot tub covers will require a template provided by you for the manufacturer to build your cover properly. This includes spas with speaker bumps, waterfalls, or cut outs for rails or controls. Make sure to measure hot tub and spa covers to the very outside of the acrylic.