Accurately determining the dimensions of your round pool is the critical first step in selecting a properly fitting cover. An incorrect measurement leads to a cover that is either too small to be functional or excessively large, causing frustrating wrinkles and poor water drainage. This guide provides a clear, step-by-step process to measure your round pool for a cover, ensuring a tight fit and long-term durability.
Why Precision Matters for Round Pool Covers
Unlike rectangular pools, round pools require specific diameter measurements to ensure the cover fits securely. A cover that is even a few inches off can slip off the wall, collect excess water, and become a safety hazard or be damaged by wind. Taking the time to measure correctly saves money by preventing the need for premature replacements and reduces safety risks associated with loose covers.
Measuring the Pool Diameter
The standard method for measuring a round pool involves finding the exact diameter. This is the length of a straight line passing through the center of the circle, connecting two points on the edge. You will need a measuring tape, a helper, and a notepad to record the results.
- Ensure the pool water is calm and the surface is as still as possible.
- Have a partner stand at one edge of the pool, holding the zero end of the measuring tape at the top of the wall.
- Stretch the tape measure directly across the pool to the opposite edge, keeping it taut and level.
- Record the measurement where the tape meets the top edge on the opposite side.
Accounting for the Wall Skirt
Above-ground pools often have a wall skirt, or flange, that extends down from the top rail. This skirt is essential for the cover’s anchoring system, so the measurement must include it. If you only measure the rail itself, the cover will not wrap around the skirt, leading to an improper fit that compromises the cover’s effectiveness.
When measuring, ensure the tape runs from the top outer edge of the skirt, across the pool, to the top outer edge of the skirt on the opposite side. This total diameter is the figure you will use when ordering your cover.
Taking Multiple Measurements
Even perfectly round pools can have slight imperfections or installation variations. To guarantee accuracy, always take at least two measurements: one north-to-south and one east-to-west. If the two measurements differ by more than an inch, take a third measurement to confirm the true diameter. Using the largest measurement ensures the cover will stretch over the pool rather than be too tight.
| Measurement # | Diameter (Feet) | Notes |
|---|---|---|
| 1 | 18 | North to South |
| 2 | 18.25 | East to West |
| 3 | 18 | Diagonal |
Ordering the Correct Cover Size
Once you have determined your pool’s diameter, you can confidently order your cover. Round pool covers are typically sold in specific diameter increments, such as 12 feet, 15 feet, 18 feet, and 21 feet. Always order the size that matches the largest measurement you took. If your pool measures 18 feet 2 inches, you should order the 19-foot cover to allow for the necessary overhang and secure fit.
Final Checks Before Installation
Before placing the cover on the water, double-check that the diameter marked on the packaging matches your calculated pool size. Unroll the cover on a clean surface to ensure there are no manufacturing defects. When installing, center the cover on the pool and secure the anchors evenly around the wall skirt to maintain tension and prevent water pooling during winter months.
