In order to insure the proper fit for your replacement spa cover the more information that you can provide us the better. The spa manufacturer, model, and year made if you have it, lets us cross check with the physical measurements that are taken. All measurements should be made in inches. You can measure the old cover or the spa. If you are measuring the spa, the measurement should be taken to the outside of the acrylic edge. Rounding up to the nearest inch is acceptable but you should not round down. The first step in measuring the spa is to identify the shape of the spa (see the examples below).
Be careful in recognizing whether the spa has cut, rounded corners, or square corners when measuring a rectangular or square spa. Measure the spa with a tape measure and another person to insure accuracy.
MEASURING A RADIUS CORNER
To provide the information necessary on a radius corner, extend two imaginary lines to a point where the sides would have met had the corner been square. Provide the distance from the break of the curve (point A) to the imaginary point (point B). This will be your radius measurement. Use two rulers to extend the sides of your spa tub to a point. This will make it easier to measure from point A to B.