BeyondNice receives calls daily from customers who are nervous about measuring the rounded corners for their cover order. We will cover this topic in such great detail, you will be more confident in your measurement when you go back to measure the rounded corner of your spa.
First, most hot tubs have rounded corners. The question is, how rounded? Is it rounded like a soup can, gallon paint can, or a 50 gallon trash can? The measurement of the curvature is called the radius. Normally, a radius is measured as half the distance across a circle, or half the diameter of any circle. When measuring your hot tub, it can be a little bit more difficult as the corner represents only one quarter of a circle! Make sense?
If we take into consideration a corner that has a 3 inch radius, the corner should look about the size of a rounded soup can. When measuring the rounded corner BeyondNice has many photos and tools on the site to help. The short video we have made on how to measure the radius has been one of the most beneficial tools. You can view our video below.
This picture shows a hot tub with a 7.5 inch radius. Imagine if the cover was made with a 7 inch radius, and you can see in this picture the extra slack it would provide, compared to where the cover would set if the radius was made exactly 7 inches.
The radius measurement should always be rounded DOWN when it falls between full inches. The smaller the radius, the less will be cut off the corner of the cover. When a radius measurement is too large, more of the cover will be cut off for a shorter curve and the hot tub will be exposed and stick out from underneath the top.
The rule is it is always better to have the cover slightly larger to insure some looseness as covers do tend to shrink over time. A looser fit will also help your cover to close more easily with the skirt less likely to fold up under the cover. If the cover is too small you will not have a hot tub cover at all.
With this instruction, and the tools on this site, you will be more confident when you measure. If you do not have a carpenter’s square, as shown in our photos, use any straight edge – a 2×4, a newspaper, a yard stick – and lay it along one side. Then simply use a standard tape measure to measure back from your straight edge to the side of the hot tub.