How to measure a hot tub cover the right way

If it's time for a new hot tub cover, correct measurements are needed to ensure the perfect fit, even if your hot tub dealer has your model's dimensions on file. In case you've got measuring tape jitters, we'll walk you through the steps so you know how to measure a hot tub cover the right way.

Measure the hot tub

  • 1 Measure lip to lip. Regardless of the shape your spa, you should measure from lip to lip, or the outside dimension of the acrylic which is the same as lip to lip. After you have a lip to lip measurement you may add up to 1" on both length and width. This will give you a 1/2" of play all around your spa cover.
  • 2 Measure the skirt. The skirt is the flap that hangs from the bottom of your cover. The skirt protects the spa surface and aids in heat retention, 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. If anything 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".
  • 3 Measure the radius. This is how you measure a curved edge on your hot tub, and it's the step that makes everyone worried. As the lower diagram on the left shows, the easiest way to measure a radius, which 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 corners of the hot tub cover. Your hot tub cover radius will always be an even number. To measure radius "C": extend straight lines indicated in red by laying straight edges against the sides of the hot tub. Measure from point "Y" to point "Z".

How to measure different shapes of hot tubs

  • Square cover. The square hot tub cover is the easiest cover to measure. Just measure your hot tub from lip to lip. The only other dimension you will need is the skirt length.
  • Rectangular cover. Measure for a rectangular hot tub cover the same way as for a square cover, but make sure you request the fold direction you require. Most companies will cut the longest of the two sides in half unless you tell them otherwise.
  • Square or rectangular cover with rounded corners. Follow the square and rectangle spa cover procedure and add the radius measurement.
  • Round cover. The round spa cover is easy to measure as well, since you only need the lip-to-lip measurement. If your old cover is measurable, you can also measure across the seam. The only other measurement needed is the skirt length.
  • Octagonal cover (8 equal-length sides). For the octagon spa cover measure from lip to lip add 1" 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 Shapes Most of these covers will require a template provided by you to complete your cover properly. This would include spas with speaker bumps, waterfalls, or cut outs for rails or controls.
  • Be sure to identify strap and handle locations, or any other features of your cover. Identifying strap locations will ensure your straps line up with the receiving end that is screwed to your spa cabinet. Measure the distance from the corner of the cover and mark on the image at the bottom of the form. The same can be done for the handles on the cover if you are concerned about placement. Does your cover attach to a cover lifter, have cut outs for speakers, have reinforced plates? Please let us know.

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