How to Measure for a Pool Cover (Get the Right Fit Every Time)

Buying the wrong size pool cover is one of the most common mistakes pool owners make. Too small and it won't stay secured. Too large and it sags, collects water, and becomes a safety hazard.

This guide walks you through exactly how to measure your above ground pool for a cover — whether it's round, oval, or rectangular — so you get the right fit the first time.

Why Sizing Matters

A properly sized pool cover:

  • Stays securely in place even in high winds

  • Prevents debris, rain, and UV rays from reaching your pool water

  • Lasts longer because it's not under constant strain from a poor fit

  • Is easier and faster to install

What You'll Need Before You Measure

  • A flexible measuring tape

  • A helper (optional but useful for larger pools)

  • A notepad to record your measurements

How to Measure a Round Pool

Step 1: Find the Diameter

Measure straight across the widest point of your pool — from the outside edge of the pool wall on one side to the outside edge on the other side.

Important: Measure the outside edge of the pool frame, not the water surface.

Step 2: Add 2–4 Feet

Always order a cover that is 2 to 4 feet larger than your pool's actual diameter.

Round Pool Cover Size Chart

Pool Diameter Recommended Cover Size
10 ft 12 ft cover
12 ft 14 ft cover
15 ft 17 ft cover
18 ft 20 ft cover
21 ft 23 ft cover
24 ft 26–28 ft cover
27 ft 29–30 ft cover
28 ft 30–32 ft cover
30 ft 32–33 ft cover
33 ft 35 ft cover


How to Measure a Rectangular Pool

Step 1: Measure the Length

Measure from the outside edge of one short wall to the outside edge of the opposite short wall.

Step 2: Measure the Width

Measure from the outside edge of one long wall to the outside edge of the opposite long wall.

Step 3: Add 2–4 Feet to Each Dimension

Add 2 to 4 feet to both your length and width measurements. Example: A 12 × 24 ft pool needs at least a 14 × 26 ft cover.

Rectangular Pool Cover Size Chart

Pool Size Recommended Cover Size
5 × 8 ft 7 × 10 ft cover
6 × 12 ft 8 × 14 ft cover
7 × 13 ft 9 × 15 ft cover
8 × 14 ft 10 × 16 ft cover
10 × 20 ft 12 × 22 ft cover
12 × 24 ft 14 × 26 ft cover
15 × 30 ft 17 × 32 ft cover
18 × 36 ft 20 × 38 ft cover


How to Measure an Oval Pool

Step 1: Measure the Length

Measure the longest dimension of your oval pool from outside edge to outside edge.

Step 2: Measure the Width

Measure the widest dimension of your oval pool from outside edge to outside edge.

Step 3: Add 2–4 Feet to Each Dimension

Add 2 to 4 feet to both dimensions.

Oval Pool Cover Size Chart

Pool Size Recommended Cover Size
7 × 10 ft 9 × 12 ft cover
7 × 13 ft 9 × 15 ft cover
8 × 14 ft 10 × 16 ft cover
10 × 15 ft 12 × 17 ft cover
10 × 20 ft 12 × 22 ft cover
12 × 20 ft 14 × 22 ft cover
15 × 30 ft 17 × 32 ft cover
18 × 34 ft 20 × 36 ft cover

Common Measuring Mistakes to Avoid

  • Measuring the water surface instead of the pool frame — Always measure the outer edge of the pool frame.

  • Buying an exact-size cover — If your pool is 24 ft, you need at least a 26 ft cover.

  • Measuring at an angle — Always measure straight across in a perfectly perpendicular line.

  • Not accounting for pool accessories — Make sure your cover can clear ladders or skimmer boxes.

What If I'm Between Sizes?

Always go with the larger size. A slightly oversized cover is far easier to work with than one that's too small.

Frequently Asked Questions

What size pool cover do I need for a 24 ft round pool?

You need a 26 ft or 28 ft cover. Always add 2–4 feet to your pool's actual diameter to allow proper overlap and securing on all sides.

Can I use a round cover on an oval pool?

No. Round covers are cut in a circle and won't properly cover or secure on an oval pool. Always use a cover that matches your pool's shape.

What if my pool size isn't on the size chart?

Choose the next size up. For unusual dimensions, contact us at zanhui022@163.com and we'll help you find the best fit.

Does the cover size include the overlap or is it the exact pool size?

Cover sizes listed are the actual cover dimensions — not your pool size. For example, a "26 ft cover" is 26 feet across. Your pool should be 22–24 ft to use this cover properly.

How much overlap do I need on each side?

A minimum of 12 inches (1 foot) of overlap on each side is recommended. More overlap gives you more securing options and better protection in high winds.

Ready to Find Your Cover?

Now that you know your pool's measurements, browse our full range of above ground pool covers by shape and size:

Still not sure? Email us at zanhui022@163.com and our team will help you choose the right cover for your pool.