18 x 40 ft Inground Pool Winter Covers

A 18 x 40 ft inground pool takes a 23 x 45 ft or 24 x 46 ft cover. The extra is the overlap, 2.5 or 3 ft on every side, and it laps onto the deck where the water tubes hold it down. Every cover on this page is listed by the pool it fits, and the covers cut for a larger pool that still work here are under Also fits.

7 covers made for this size
More covers made for a 18 x 40 ft pool 2 out of stock

Also fits a 18 x 40 ft pool

These are cut for a larger pool but still work here. Each card shows the overlap it leaves on the sides and on the ends, so you can check it against your deck.

More covers that fit 3 out of stock

Inground winter cover questions

What size winter cover fits an 18 x 40 ft inground pool?

A 23 x 45 ft cover, or a 24 x 46 ft from the Cool Covers King line. The 23 x 45 is the pool plus 5 ft and leaves 2.5 ft a side; the King is plus 6 ft and leaves 3 ft.

How many water tubes does an 18 x 40 ft pool need?

17 tubes of 8 ft, or 14 of 10 ft. The 23 x 45 ft cover measures 136 ft around, and the tubes lie end to end on the overhang.

Which covers cut for a bigger pool still fit an 18 x 40 ft pool?

A 25 x 45 ft cover leaves 3.5 ft on the sides and 2.5 ft on the ends. A 25 x 49 ft leaves 3.5 ft and 4.5 ft, and a 26 x 46 ft leaves 4 ft and 3 ft. They appear under Also fits.

Do I drain the pool before covering it?

No. Never drain an inground pool. The water is what holds the shell down against the groundwater around it. The level comes down a little for winter, and the cover's 2.5 ft of overlap is cut to reach from the lowered waterline back up over the coping.

What are the 18 x 40 ft covers made of?

Triple laminated polyethylene with heat sealed seams, some of it 8 mil, in black on tan or silver on black. Stated warranties at this size run from 8 to 25 years, and each card lists its own.

Other pool sizes

Select pool size

12 x 20 ft 12 x 24 ft 14 x 28 ft 16 x 24 ft 16 x 32 ft 16 x 36 ft 16 x 38 ft 16 x 40 ft 18 x 36 ft 18 x 40 ft 20 x 40 ft 20 x 44 ft 20 x 45 ft 24 x 40 ft 25 x 40 ft 25 x 45 ft 25 x 50 ft 30 x 50 ft 30 x 55 ft 30 x 60 ft
Everything else: all inground winter covers