The Ultimate Above Ground Pool Cover Size & Material Guide: How to Choose the Perfect Fit

If you've ever pulled a cover off your pool in the spring only to find it sagging into a swamp of green water, ripped along the top rail, or half-full of last autumn's leaves anyway, you already know the painful truth: not all pool covers are created equal. Picking the wrong one isn't just frustrating—it’s an expensive mistake you don't want to make twice.

When winterizing an above ground pool, your cover is the single line of defense protecting your liner, your filtration infrastructure, and your water balance from freezing temperatures, heavy snow loads, and destructive UV rays.

The good news? Choosing the right cover is simple once you know how the industry sizes them and which materials actually hold up against real weather. In this comprehensive guide, we'll walk you through the four essential pillars of buying a pool cover: matching shapes, calculating exact dimensions, breaking down material weights, and choosing a fastening system that won't blow away in a winter storm.

Step 1: Start With Your Pool's Exact Structural Shape

Above ground pool covers are cut geometrically to match specific pool engineering. They are absolutely not one-size-fits-all, and attempting to improvise will ruin your winterization strategy. Before looking at a single size chart, confirm which design your pool requires:

1. Round Pool Covers

The most traditional and widely used format. Circular pools distribute water tension evenly, and their covers are cut as perfect circles. They rely on a single continuous cable or strap running beneath the outer top rail.

2. Oval Pool Covers

Engineered for elongated pools that combine straight side walls with curved ends. Oval covers require a specialized radius cut. Trying to force a standard rectangular tarp or an oversized round cover over an oval frame leaves massive loose pockets of fabric that act like sails in high winds, leading to torn grommets.

3. Rectangular Pool Covers

Typically used for modern metal-framed pools, hybrid structural layouts, or setups integrated into customized wooden wrap-around decks. These require precise corner reinforcement since right angles experience higher friction against the pool frame during storms.

Why Shape Alignment Matters: A shape mismatch creates loose gaps. Biting winter winds will slip underneath those gaps, creating a "parachute effect" that can rip heavy-duty hardware right out of your yard or dump freezing rain straight into your clean chemical balance.

Step 2: How to Measure Your Pool (Avoid the Most Common Buyer Mistakes)

To find your cover size, you must measure the pool infrastructure itself. Do not measure your surrounding wooden deck, do not guess based on your safety fencing, and do not rely on your water liner box dimensions. You need the actual top rail-to-top rail metrics。

Understanding the "Overlap" (Overhang Margin)

When you look at a pool cover size chart, you will see terms like "Pool Size" and "Cover Size." A cover must be significantly larger than the pool itself. This extra material is called the overlap (or overhang), and it allows the cover to drape down the outer walls of your pool so it can be cinched tightly beneath the top rail.

• Standard Overlap: Most standard winter covers include a 3-foot or 4-foot overlap. For example, if you measure your round pool diameter as exactly 24 feet, you need a cover listed for a 24 ft Round Pool (the physical fabric circle will actually measure 27 or 28 feet in diameter).

• When to Size Up: If your pool features an upgraded extra-wide top rail (8 inches or wider), or if you intend to use a massive ice equalizer air pillow beneath the cover, you should choose a cover with a generous 4-foot overlap. The air pillow pushes the center of the fabric upward, which strips away your outer overhang margin.

Step 3: Material Breakdown—What Are Pool Covers Made Of?

The material composition dictates how many seasons your cover will survive. Remember: Intense summer UV rays—not winter ice—are the number one killer of outdoor covers. Solar exposure bakes cheap plastics, turning them brittle until they rip like dry paper under the first heavy snowfall.

At Faircovers, we engineer our winter covers using commercial-grade 420D Oxford fabric bonded to an internal waterproof Polyurethane (PU) lining. This creates the ultimate sweet spot for residential pool owners: it’s incredibly durable and puncture-resistant against falling branches, yet flexible enough to fold down into a compact storage bag during the summer.

Step 4: Fastening Systems—Securing Against High Winds

Even a cover made from bulletproof material is completely useless if it blows into your neighbor's yard during an autumn storm. How your cover anchors to your pool wall is paramount.

1. Drawstrings & Elastic Hems (The Budget Weakness)

Flimsy drawstrings rely on basic manual knots. Over a long winter, freeze-thaw cycles cause moisture to expand and contract, which slowly stretches and loosens the line. If wind gets under the fabric, it creates a parachute effect that tears out the perimeter grommets.

2. Winch and Steel Cable Systems

A heavy-duty vinyl-coated steel cable threads through reinforced grommets around the entire perimeter of the cover. A mechanical aluminum winch (ratchet) is then used to crank the cable down until it locks tight directly under the pool's top ledge. This mechanical lock prevents the cover from slipping upward, making it highly secure against severe storms.

3. Integrated Ratchet Buckle Straps

The gold standard for premium covers. Rather than a single continuous wire, individual heavy-duty straps hook directly to the pool frame or anchors. This allows you to adjust tension independently across different sections of the pool—ideal if your pool features step obstructions or connects directly to an adjacent deck.

The Two Accessories Most Homeowners Overlook

If you want your pool cover to perform flawlessly all winter, you need to manage two major physics problems: water expansion and surface weight.

1. The Ice Equalizer (Air Pillow)

When water freezes, it expands outward. In an above ground pool, this expansion exerts immense pressure on your structural metal walls, which can crack your frame. By floating an inflated air pillow in the exact center of the water before closing, you force the ice to expand inward against the soft pillow instead of your pool walls. Bonus: It tents the center of the cover slightly, forcing rain water to drain toward the outer edges rather than pooling in the middle.

2. The Submersible Cover Pump

Solid, waterproof covers accumulate rain and melting snow on top of them. One gallon of water weighs roughly 8.3 pounds. If a heavy storm dumps several inches of rain on a flat cover, you are suddenly asking your pool top rails to hold thousands of pounds of dead weight. A simple, automatic submersible cover pump siphons this water off throughout the winter, saving your pool structure from collapsing.

Quick Checklist: Match Your Climate to the Right Cover

Mild & Sunny Climates (Texas, California, Florida): Your primary enemy is UV degradation and dust. You need a cover with a silver heat-reflective inner lining or a premium UV-stabilized coating to stop the sun from breaking down your pool liner.

Heavy Snow & Freezing Climates (Midwest, Northeast US): Your primary enemies are heavy snow loads and sub-zero cracking. You require a high-denier material (like 420D Oxford) that retains its flexibility below 0°F, backed by a robust winch-and-cable system to hold up under heavy winter accumulation.

Ready to Protect Your Backyard Investment?

Choosing the perfect above ground pool cover comes down to three things: selecting your correct geometric shape, measuring accurately from rail-to-rail, and investing in a high-denier fabric engineered to withstand your local climate. Get it right now, and opening your pool next spring will be a quick afternoon breeze rather than a stressful battle against a muddy backyard swamp.

Explore our complete catalog of commercial-grade, weather-tested above ground pool covers, custom-cut for your specific frame size:

• 👉 Shop Heavy-Duty Round Pool Covers (Winch & Cable Included) →

• 👉 Shop Secure Oval Pool Covers →

• 👉 Shop Premium Rectangular Pool Covers →

• 👉 Browse the Entire Faircovers Pool Protection Catalog →

Unsure if your pool top rail can handle a standard cable system, or dealing with custom deck obstructions? Drop a line to the Faircovers support team—our product specialists are based right here to help you map out the exact sizing blueprints you need.

Related Expert Guides on the Faircovers Blog:

• How to Winterize Your Above Ground Pool Safely (The Step-by-Step Closing Guide)

• 5 Signs It’s Time to Retire and Replace Your Old Winter Pool Cover

• Waterproof vs. Water-Resistant Patio Furniture Covers: Which Do You Need?