91 x 91 Hot Tub Cover — Size, Fit and 117 Spas That Take It
A hot tub measuring 91" × 91" takes the AIRCAP 1™ Large, which fits square spas 89–91". That is the whole answer — but measure your own spa before ordering rather than trusting the size of the cover you are replacing, because cabinets vary between model years and a cover bought to the wrong number is the most common ordering mistake there is.
Measure straight across the top of the cabinet, edge to edge, both ways. If the two numbers differ, use the larger one. If you land between two sizes, round up: an oversized cover overhangs by a fraction, which is how a spa cover is meant to sit, while an undersized one will not seal along the edges.
The AIRCAP 1™ Large fits square spas 89–91" — $1,195, the same as every other size.
Buy the AIRCAP 1™ LargeWhich hot tubs are 91" × 91"?
112 of the 1093 models in our Spa Fitter measure 91" × 91", across 27 brands, and 5 more round up to it (listed below). If yours is on this list, the size question is settled — click through for its own page.
Also rounds up to 91" × 91"
5 more models are not printed as an exact 91" square: one or both sides fall a fraction short. The rule is to round up, so they take the same Large.
| Brand | Rounds up to 91" × 91" |
|---|---|
| Coast Spas | Lanai (90" x 90.5", 0.5" short) |
| Passion Spas | Admire (90.6" x 90.6", 0.4" short), Devotion (90.6" x 90.6", 0.4" short), Euphoria Mighty Wave (90.6" x 90.6", 0.4" short) |
| Superior Wellness | Platinum Oslo (90.5" x 90.5", 0.5" short) |
That makes 91" the 2nd most common of the 18 square footprints in the Spa Fitter (117 of 1093, 10.7%); the most common is 84" × 84" with 257. Next door, 90" × 90" lists 30 (plus 3 that round up) and 92" × 92" lists 73 (plus 9 that round up). Artesian Spas and Premium Leisure build the most at this size — 13 each of the 117.
What if my spa is not exactly 91"?
91" (231.1 cm) is the largest square the Large is rated for. Half an inch more rounds up to 92" and takes the X-Large instead, so measure carefully at this size.
The Large covers everything from 89–91" across, so you do not need to hit 91" exactly. Outside that band, the AIRCAP 1™ comes in six sizes spanning 77" to 94" — the two-measurement guide will place you, or you can look your model up directly in the Spa Fitter.
One limit worth stating plainly: these are covers for square spas. If your cabinet is round, octagonal or a rectangle, no size here will fit it, and the alternatives guide covers what will.
Nearby measurements: 89" × 89" · 90" × 90" · 92" × 92". Every size from 77" to 94" has its own page, listed on the Spa Fitter.
What a 91" × 91" cover costs
The AIRCAP 1™ Large is $1,195 — the same price as every other size, including the pump, three Ziptech™ skirt depths and tie-down straps, with free shipping to all 50 states. There is no size surcharge, which is unusual in this category: most makers price a cover by its square footage, so a bigger spa costs more. For how that compares with foam and the other constructions, see what a hot tub cover costs.
It weighs 35–40 lb and, with no foam core to absorb water, never gains weight — the one number a foam cover cannot promise.
Frequently asked questions
What size cover fits a 91" x 91" hot tub?
A 91 inch square hot tub takes the AIRCAP 1 Large, which fits square spas 89 to 91 inches across. Measure straight across the top of your cabinet both ways and use the larger number; if it falls between two sizes, round up.
Which hot tubs are 91" x 91"?
112 models in our Spa Fitter measure 91 by 91 inches across 27 brands (Aahs Spas, AquaLife Spas, Aquavia Spa and 24 others), and 5 more round up to it. Each one has its own page listing the cover size it takes.
Is 91 inches the largest spa a Large fits?
Yes. The Large is rated for square spas 89 to 91 inches across, so 91 is its upper limit. A cabinet that measures even half an inch over rounds up to 92 and takes the X-Large.
How much does a 91" x 91" hot tub cover cost?
The AIRCAP 1 is $1,195 in every size, including the pump, three Ziptech skirt depths and tie-down straps, with free shipping to all 50 states. There is no size surcharge, so a 91 inch cover costs the same as the smallest one we make.
Find the size that fits your spa
The AIRCAP 1™ Large fits square spas 89–91" — $1,195, the same as every other size.
Buy the AIRCAP 1™ LargeNot sure of your size? Measure in two steps or look up your model in the Spa Fitter.