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How To Measure a Hot Tub Cover

Hot Tub Covers

How to measure a hot tub cover

When ordering a new hot tub cover, it is important to know how to measure a hot tub cover to get a correctly fitted cover and ensure no heat is lost. This not only ensures that your hot tub stays at the set temperature but will save you lots of money. Below is a guide on how to measure a hot tub cover correctly. For more information contact Healthy Hot Tubs on 0333 7720082.

Measuring Your Hot Tub’s Size

If you are happy with the fit of your existing cover, by all means measure your existing cover but remember this will probably have shrunk over time by soaking up water and heat.
When measuring your spa, always remember to measure from one lip to the other. The lip may be the edge of the acrylic or the wooden cabinet depending on your model. It is recommended to add around 0.5’’-1’’ to both the length and width to allow for easy removal, as too tight a fit will make it difficult to remove the cover.

Cover Skirt Measurement

The skirt that overhangs your acrylic or cabinet is important to prevent heat loss around the edges. The length of your existing cover skirt is usually recommended or a skirt of around 4’’ is normal. If you have a wooden ledge around the acrylic, too long a skirt could lead to problems with the cover fit, ensure that this is considered when measuring the cover.

Measuring the Radius of Your Hot Tub Cover

The what? The radius! Commonly frustrating for most hot tub owners when they first order a new cover. Getting this right is again vital to prevent heat loss through the corner of the cover.
The easiest way to measure is using a carpenter’s square, however you can easily make of one of these using strong cardboard. The radius length is from the start of the bend to the imaginary point of the corner if the cover was square. The smaller the radius, the more square the corner of the hot tub cover.

The pictures below show you how to measure your corner radius.

how to measure a hot tub cover - Corner Radiushow to measure a hot tub cover - Corner Radius



How to Measure Certain Shaped Covers

Square - Easy. Measure one length, you won’t have a radius and will only need a skirt length to complete your order. Be careful, most hot tub covers are not totally square and without a radius, double check to prevent errors.

Rectangle - Measure both lengths and specify which length needs to be the folding length. By default, we will assume that the cover folds along the long side.

Square with Radius - Follow the instructions of a square cover and measure the radius.

Rectangle with Radius - Follow the instructions of a square cover and measure the radius.

Round - Measure the diameter of the hot tub cover and this will be sufficient.

Octagonal - Measure the overall length and also measure the length of each section on the octagon.


  • Remember you can make your own carpenters square using a ruler, cardboard and scissors!
  • Remember that your old and worn cover will not be totally accurate to fit your hot tub. Measure your hot tub and your existing cover and compare the difference, draw conclusions from both.
  • Many people send us length and width measurements that are 1 inch out, these hot tubs are most probably square but the cover wear has led to a slight change in size, assume the cover is square if the measurements are this close.
  • When measuring a cover size, bigger is generally better, but this is your responsibility.
  • When measuring a corner, smaller is better. Round down if needed.

When calling Healthy Hot Tubs to order a new cover please select your nearest colour match from the below.

how to measure a hot tub cover - Colour Choice

For a new hot tub cover, Call Our Hot Tub Service Team Today on 0333 7720082

For our full range of services including tips on reducing hot tub costs and advice on Using Your Hot Tub In The Winter visit