How To Measure A Hot Tub Cover

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MEASURE THE SPA! NOT THE ORIGINAL HOT TUB COVER! Spa covers can warp, stretch and shrink over time and cannot be relied upon to provide accurate measurements.

A hot tub cover that is slightly oversized will function effectively. A hot tub cover that is slightly undersized will not function effectively.

Most hot tub owners choose to cover only the acrylic shell. In this instance, measure from the outside of the acrylic shell at the widest point of the “lip” (many lips are curved and the spa “‘skirt” must be wide enough to sit completely over the lip).

Occasionally, hot tub owners would like to cover both the shell and the wood lip. If so, the measurement should be taken from the outside of the wood skirt. And make sure to advise us that we are making it to cover the wood skirt!

The “Acrylic Shell Size” will be used to determine the size of the finished spa cover. The “Lip Height” will be used to determine the cover’s “Skirt” length.

Specify the  “hinge” direction. Which way will the cover fold? The dotted lines found in the diagrams on our order sheet indicate the fold direction. Make sure to take this into account when entering the spa’s “A” and “B” dimensions.

Some covers have rounded corners. Be sure to measure all corners to determine if they are ALL the same size! (Note: A slightly smaller radius will slightly over hang the spa while a larger radius will not cover the spa completely). One method of determining a spa’s corner radius is to use a “carpenter’s framing square”. Hold it up against the corner of the spa as you see in the diagram below. The radius of the corner is the distance between “A” and “‘B”.

Alternatively, it is acceptable to place a sheet of white 8 x 11 paper over top of the corner, draw a line (tracing) of the corner, and fax it along with the order sheet.

It is extremely important that you submit the correct measurements so that it will fit properly. Even if we have your Hot Tub make and model on file, take time to double check the measurements to be sure.

Step 1 – Measuring your Hot Tub

Regardless of the shape of your Hot Tub, measurements should be taken from the hot tub itself 1st and your old hot tub cover 2nd. Your old cover can warp or shrink over time. However if your old spa cover still fits well, you can use the measurements for verification purpose once you’ve measured the hot tub. If measurements between the hot tub and the old cover differ, we advise you to use the measurements from the hot tub.

Regardless of the shape your Hot Tub, you should measure from the outside dimension of the acrylic (also known as lip to lip). After you have a “lip to lip” measurement you may add up to 1″ on both length and width to your final measurement. This will give you a 1/2″ of play all around your Hot Tub Cover.

Step 2 – Measuring the Cover Radius (if applicable)

Many spa covers have rounded corners which means you must measure the corner radius. This is the measurement that scares everyone. Fear not…it’s really quite simple

The easiest way to measure the corner radius of your hot tub cover is to use a carpenter’s square. Place the square on the corner of your existing cover or on the corner of your hot tub.

The measurement comes from the inside corner of the carpenter’s square (A) to the point where it first touches the hot tub (B). This distance (R) equals the radius of the hot tub’s rounded corner

Step 3 – Measuring the hot tub cover skirt

The Cover Skirt is the flap that hangs from the bottom of the hot tub cover. The purpose of the skirt is to protect side of the acrylic that is not concealed by the hot tub cover. The sun’s UV rays have a negative effect on acrylic.

Measure the skirt length from the top of the acrylic to the bottom of the lip (or if measuring off of the old cover, measure from bottom of the cover to the edge of the skirt). If you have a wood rail as in the picture above, measure from the top of the wood rail to the top of your hot tub acrylic. If the skirt is too long and resting on the wood rail, it might bunch up and push the cover up. If you do not have a wood rail, then measure from the top of the acrylic to the bottom of the lip and add 1/2″.

Step 4 – Measuring the Strap Length/Position

You can request the length of the strap as well as the location however these measurements are not guaranteed and are not covered under our return policy. The strap length should be measured from the bottom of the skirt to the end of the buckle. When requesting specific strap locations, measure from the centre of the side in which the straps are to be located. Example: 10″ from the centre of side A

Measuring a Square Hot Tub Cover

A Square hot tub cover is very easy to measure. From the Hot tub itself, measure the outside dimension of the acrylic or spa shell (also known as lip to lip), and add 1″ to each dimension. Then measure the skirt length following Step 3 above.

Measuring a Rectangle Hot Tub Cover

The same principals apply as with the square hot tub cover. From the Hot tub itself, measure the outside dimension of the acrylic or spa shell (Width and Length), and add 1″ to each dimension. Then measure the skirt length following Step 3 above to measure the hot tub skirt (flap).

Measuring a Square Hot Tub Cover with Round Corners (Radius Corner)

Follow the square or rectangle measurement steps as noted above and then measure the corner radius as explained in Step 2 above. Then measure the skirt length following Step 3 above.

Measuring a Round Hot Tub Cover

To measure a round hot tub cover, we need to get the diameter measurement. The diameter of a round hot tub is a straight line across the center (the widest point). Add 1″ to this measurement. To verify your final measurement (after you added 1″) against your old hot tub cover, measure along the seam. Then measure the skirt length following Step 3 above.

Measuring a Cut Corner Hot Tub Cover

Follow the square or rectangle measurement steps as noted above by measuring Width and Length of the Hot tub acrylic (shell). You will also need the width measurement of the cut corner. If your Hot Tub has multiple cut corners and they vary in size, measure each of them individually. Then measure the skirt length following Step 3 above.

Measuring an Octagon Hot Tub Cover

An Octagon hot tub cover has 8 equal sides. Measure the entire width of the hot tub acrylic (shell) and also measure the width of one of the 8 sides. Then measure the skirt length following Step 3 above.

Measuring a Hexagon Hot Tub Cover

A Hexagon hot tub cover has 6 sides. From the Hot tub itself, measure the outside dimension of the acrylic or spa shell (Width and Length). Then measure the angled side as show in the image. Then measure the skirt length following Step 3 above.

If you have any questions or need advice on how to measure your hot tub cover please contact and we will be glad to help.