Which solar cover to buy for your pool size
You already know your pool is an 18 ft round or a 16 by 32. This is which cover to put on it — and the counter-intuitive rule about thickness that applies once the pool gets big.
Quick picks
One pick per common pool size, chosen on fit first and thickness second. Live prices come from the retail listing.
| # | Product | Best for | Price |
|---|---|---|---|
| 1 |  Best for an 18 ft round Sun2Solar Blue 18 ft Round Solar Cover, 12 Mil 12 mil, the sensible middle of the range, at the commonest above-ground size. | An 18 ft round above-ground pool | |
| 2 |  Best for a 24 ft round Blue Wave 24 ft Round Solar Pool Cover, 8 Mil 8 mil and an 18 lb dry weight, because at 24 ft the cover you can actually move is the one that gets used. 3-year warranty. | A 24 ft round above-ground pool where one person handles the cover | |
| 3 |  Best for a 16 x 32 inground Sun2Solar Blue 16 ft x 32 ft Rectangle Solar Cover, 8 Mil The commonest rectangle, in the lightest grade. Trim allowance included for steps and corners. | A 16 x 32 ft inground pool where handling weight matters more than lifespan | |
| 4 |  Best if you want it to last Sun2Solar 1600 Series Ultimate Blue Solar Cover The 1600-series heavyweight, for a pool where the cover lives on a reel and comes off daily. | An inground pool you cover most nights, every season | |
| 5 |  Buy this with anything over 18 ft Feherguard Premium Above-Ground Solar Cover Reel System Above about 400 sq ft a cover without a reel is a cover that stays in the garage. Sized from 12 to 30 ft. | A round or oval above-ground pool wider than 24 ft |
#ad We earn a commission if you buy through this link, at no extra cost to you. It never changes the ranking. How this site is funded. Prices last checked October 17, 2026.
Start with the rule, because it decides everything else
Solar covers are sold oversized on purpose. You buy the nominal size of your pool, float it on the water, let it relax in the sun for a few hours, and then trim it to the waterline with ordinary scissors. Every manufacturer here builds in the overlap and expects you to cut it. Our measuring and cutting guide walks through the method, including the one exception for above-ground pools where the cover has to sit inside the rail.
This page assumes you have done that and are now asking a narrower question: for my size, which cover.
The thickness rule reverses as the pool gets bigger
The exception is a pool with a reel. A reel removes the handling argument completely, and at that point thickness becomes a pure durability decision and the heavy cover wins. See solar cover reels.
The common sizes, and what to put on them
| Pool | Surface area | Thickness we would buy | Why |
|---|---|---|---|
| 12 ft round | About 113 sq ft | 16 mil | Small enough that weight is irrelevant. Buy for lifespan. |
| 15 ft round | About 177 sq ft | 12 to 16 mil | Still a one-person cover at any thickness. |
| 18 ft round | About 254 sq ft | 12 mil | The crossover. 12 mil is durable and still manageable wet. |
| 21 ft round | About 346 sq ft | 8 to 12 mil | Getting heavy. 12 mil only if you have a reel. |
| 24 ft round | About 452 sq ft | 8 mil | One-person handling wins. Thicker only with a reel. |
| 27 to 30 ft round | 573 to 707 sq ft | 8 mil plus a reel | At this size the reel is not optional. |
Surface area is pi x radius squared. It is worth knowing because it is what determines the handling weight, and because cover prices scale with it rather than with diameter.
| Pool | Surface area | Thickness we would buy | Why |
|---|---|---|---|
| 12 x 24 ft | 288 sq ft | 12 to 16 mil | Manageable without a reel if you are patient. |
| 14 x 28 ft | 392 sq ft | 12 mil with a reel, 8 without | The point where most people give up hand-handling. |
| 16 x 32 ft | 512 sq ft | 8 mil without a reel, 16 with | The commonest inground size, and firmly reel territory. |
| 18 x 36 ft | 648 sq ft | Reel, then whatever thickness you like | Not a hand-handled cover at any thickness. |
| 20 x 40 ft | 800 sq ft | Reel, and consider two covers | Some owners run two half-width covers instead of one. |
Rectangles are sold to nominal dimensions with overlap to trim. An L-shape, a kidney or anything with a bench is bought as the smallest rectangle that covers the whole pool and cut to shape.
Round, oval, rectangle — and what to do about everything else
Most pools are not a catalog shape. The answer for every irregular pool is the same: buy the smallest rectangle that entirely covers the water, float it, and cut. A kidney-shaped 16 x 32 pool takes a 16 x 32 rectangular cover and a pair of scissors.
Ovals are the one case worth buying to shape if you can — an oval cover on an oval pool wastes less material and is easier to get onto a reel straight. If your oval size is not stocked, the rectangle-and-trim method works.
Steps, benches and ladders. Cut around them or cut them out — cover material over a step is doing nothing, and a flap that has to be lifted every time is a flap that stops the cover being used.
Kidneys, freeforms and non-stocked ovals get their own page, because the decision there is about waste rather than size — covers for odd-shaped pools works through when buying cut to shape beats buying oversized and trimming.
Clear or blue at your size
Independent of size, though the decision interacts with it. A clear cover passes more light to the water and gains more heat on a sunny day; a blue one passes less and retains slightly better overnight. The difference is smaller than the marketing suggests, and our clear versus blue comparison runs through what each manufacturer will actually claim.
The size-specific note: on a large pool, clear covers show dirt and algae far more obviously than blue ones. That is cosmetic, and it is also the reason a lot of big-pool owners quietly switch to blue after a season.
What size cover do I need — the short version
| Round pool → buy the nominal diameter | 18 ft pool, 18 ft cover |
| Rectangle → buy the nominal dimensions | 16 x 32 pool, 16 x 32 cover |
| Odd shape → buy the smallest rectangle that covers it all | then trim |
| Then: float it, leave it a few hours, cut to the waterline |
Never buy under. A cover that is an inch short at one edge leaves a gap that evaporates all night, and there is no way to add material back.
Every pick, in detail
What each one publishes, what is good and bad about it, and — the section this category usually omits — what we could not judge without owning one.
Sun2Solar Blue 18 ft Round Solar Cover, 12 Mil
The default answer for the most common above-ground pool size. 12 mil is the thickness we would buy for a pool that gets covered most nights: heavy enough to survive a season of handling, light enough that one person can still drag it off. Supplied oversized with extra overlap so you trim it to the pool rather than hoping it fits.
Best for An 18 ft round above-ground pool
| Size | 18 ft round, supplied oversized to trim | Manufacturer |
|---|---|---|
| Thickness | 12 mil | Manufacturer |
| Color | Blue | Manufacturer |
Raises water temperature by up to 15°F
Claimed by Sun2Solar. Source #ad
No conditions, no trial period, no comparison pool. The same phrasing appears on every size and thickness Sun2Solar sells, which tells you it is a range claim rather than a measurement of this cover.
- Correct size for the commonest above-ground pool without cutting a rectangle down
- 12 mil is the sensible middle of the thickness range
- Extra overlap included, so trimming to ladders and rails is expected rather than a compromise
- The 'up to 15°F' claim is unconditioned and appears on the whole range
- Blue passes less light to the water than the clear version of the same cover
- 18 ft of wet 12 mil is heavy — this is the size where a reel starts to matter
- Seam and bubble life across multiple seasons
- How much of the 15°F is daytime gain and how much is overnight retention
- Whether the delivered size runs oversize consistently
These need a unit in hand across a season. We do not have one, so we do not have an opinion worth printing on them.
#ad We earn a commission if you buy through this link, at no extra cost to you. It never changes the ranking. How this site is funded. Prices last checked October 17, 2026.
Blue Wave 24 ft Round Solar Pool Cover, 8 Mil
The largest common above-ground round, and the one size where the thickness decision reverses. At 24 ft a 12 or 16 mil cover is genuinely hard for one person to move, so the 8 mil is often the version that actually gets used. Blue Wave backs it with a 3-year limited warranty, which is more than most bubble covers carry, and the listing prints the storage instruction that decides whether you get those three years: roll it rather than fold it, dry, in the shade.
Best for A 24 ft round above-ground pool where one person handles the cover
| Size | 24 ft round | Manufacturer |
|---|---|---|
| Thickness | 8 mil | Manufacturer |
| Weight | 18 lb dryWet and full of pool water it is far heavier, which is the real argument for a reel at this size. | Retail listing |
| Warranty | 3-year limited manufacturerLonger than the typical bubble-cover warranty, and the reason to prefer it over an unbranded 24 ft cover at a similar price. | Manufacturer |
| Maker's storage instruction | Roll rather than fold, dry before long-term storage, store in the shadePrinted on the listing. Folding creases the bubble film at the same points every time, and UV off the pool is what kills covers in storage. | Manufacturer |
- 3-year limited warranty, unusual at this price
- 8 mil keeps a 24 ft round within one person's handling
- Blue Wave prints the care instruction that actually extends the life
- 8 mil is the thinnest grade — a thicker cover would last longer if you could move it
- 452 sq ft of cover needs somewhere to go when it comes off
- No temperature claim published, which is honest but leaves nothing to check
- Whether the 3-year warranty is honored on a UV-degraded cover
- Seam life at the size where handling stress is highest
- Real thickness consistency across the sheet
These need a unit in hand across a season. We do not have one, so we do not have an opinion worth printing on them.
#ad We earn a commission if you buy through this link, at no extra cost to you. It never changes the ranking. How this site is funded. Prices last checked October 17, 2026.
Sun2Solar Blue 16 ft x 32 ft Rectangle Solar Cover, 8 Mil
The commonest rectangular inground size, in the cheapest thickness that is still worth owning. 8 mil is a genuine compromise: it is the lightest cover a person can handle alone at 16 x 32, and it is also the one most likely to need replacing after two or three seasons. If the cover will live on a reel and come off most days, spend up. If it goes on for the shoulder season and comes off for the summer, 8 mil is defensible.
Best for A 16 x 32 ft inground pool where handling weight matters more than lifespan
| Size | 16 ft x 32 ft rectangle, supplied oversized to trim | Manufacturer |
|---|---|---|
| Thickness | 8 milThe lightest thickness sold for a pool this size. The 12 and 16 mil versions of the same cover cost more and last longer. | Manufacturer |
| Color | Blue | Manufacturer |
Raises water temperature by up to 15°F
Claimed by Sun2Solar. Source #ad
The identical claim Sun2Solar prints on its 12 mil and 1600-series covers. A single figure covering every thickness in a range cannot be a measurement of any one of them.
- Standard 16 x 32 without cutting down an oversize rectangle
- Lightest option at this size, which is the difference between using it and not
- Trim allowance included for steps and corners
- 8 mil is the shortest-lived thickness Sun2Solar makes
- 512 sq ft of wet cover is a two-person job or a reel, whatever the thickness
- Same unconditioned 15°F claim as the rest of the range
- How many seasons 8 mil survives in your sun
- Whether the delivered rectangle is square to spec
- Bubble adhesion after repeated folding
These need a unit in hand across a season. We do not have one, so we do not have an opinion worth printing on them.
#ad We earn a commission if you buy through this link, at no extra cost to you. It never changes the ranking. How this site is funded. Prices last checked October 17, 2026.
Sun2Solar 1600 Series Ultimate Blue Solar Cover
The cover to buy if you intend to keep using it in five years. 16 mil is the thickest tier the category sells, and thickness on a solar cover buys durability rather than heat — Bob Vila measured every cover in its hands-on group at the same 4 to 5 degrees, from 12-mil clear to 16-mil blue. Pay the extra for the one that survives being dragged over the coping twice a day, not for a temperature difference that did not show up in the only published one-hour test in this category.
Best for An inground pool you cover most nights, every season
| Price shown for | 24 ft roundThis product is sold in several sizes on one listing. The live price and photograph on this page are the ones Amazon returns for this variant; other sizes are priced separately. | Retail listing |
|---|---|---|
| Thickness | 16 milThe manufacturer publishes no retrievable specification sheet; figure is as listed at retail. | Retail listing |
| Color | Blue | Retail listing |
| Stated lifespan | 5 to 10 years for the 16-mil tierSwim University's published figure for 16-mil covers generally, not a Sun2Solar warranty statement. | Retail listing |
| Bubble side | Bubbles face the waterCategory-wide instruction, not brand-specific. The bubbles are the insulating layer and they have to touch the water. | Published standard |
4 to 5 degrees F in one hour
Claimed by Bob Vila, measured across all covers in their group. Conditions: One hour under 2pm sun on 89 to 92 degree F days. Source
Their figure was the same for every cover they put on the water. Read our reconciliation of what a one-hour reading actually measures before you plan around this number.
- Thickest tier sold, which is where the durability difference actually is
- Blue absorbs more of the incoming energy at the surface than clear does
- Cuts oversize to your pool shape with household scissors
- Heavy and awkward at 16 mil — a large inground cover is genuinely a two-person job without a reel
- Costs meaningfully more than the 12-mil version for no measured heating advantage
- Whether the seams hold up over five seasons of daily handling
- How the bubble layer survives repeated dragging over rough coping
- Whether the stated lifespan tier holds for this specific product line
These need a unit in hand across a season. We do not have one, so we do not have an opinion worth printing on them.
#ad We earn a commission if you buy through this link, at no extra cost to you. It never changes the ranking. How this site is funded. Prices last checked October 17, 2026.
Feherguard Premium Above-Ground Solar Cover Reel System
The reel for the big above-ground pools the others do not reach, and the longest warranty in this roundup. Feherguard sells it in four size brackets from 12 to 30 ft wide, with telescopic tubes designed to cut mid-span sag and a lift-off, swing-away design. It is also, by a wide margin, the most expensive reel here, and its listing says nothing about materials or soft-sided pools.
Best for A round or oval above-ground pool wider than 24 ft
| Price shown for | Up to 30 ft wideSold in four size brackets from 12 to 30 ft; the 28 ft version is a separate listing. The live price and photograph on this page are for the up-to-30 ft system — buy the bracket for your pool. | Retail listing |
|---|---|---|
| Pool type | Round and oval above-ground poolsThe manufacturer publishes no retrievable specification sheet; figure is as listed at retail. | Retail listing |
| Tubes | Telescopic, adjustable to pool widthThe listing says the tube design reduces sagging in the middle of the pool — the problem that grows with every extra foot of span. | Retail listing |
| To swim | Lifts off and swings away | Retail listing |
| Warranty | 5 years | Retail listing |
- Reaches 30 ft wide, beyond every other reel in this roundup
- Five-year warranty, the longest here
- Telescopic tubes sized to your pool rather than a fixed length
- The most expensive reel here by a distance
- You must order the size bracket that matches your pool
- No published materials, and no statement on soft-sided pools
- Actual mid-span sag on a 30 ft run with a heavy cover
- Whether it fits soft-sided or frame pools
- What the five-year warranty excludes
These need a unit in hand across a season. We do not have one, so we do not have an opinion worth printing on them.
#ad We earn a commission if you buy through this link, at no extra cost to you. It never changes the ranking. How this site is funded. Prices last checked October 17, 2026.
Questions people actually ask
What size solar cover do I need for a 24 ft round pool?
Should I buy a bigger solar cover than my pool?
What thickness solar cover is best?
Can I cut a solar cover to fit?
What solar cover fits a 16 x 32 pool?
- U.S. Department of Energy pool-energy figures (evaporation share, BTU per pound evaporated, cover savings, recommended temperatures, wind effect)Recreonics, reproducing and attributing the U.S. Department of Energy · read 2026-09-02
- U.S. Department of Energy, Energy Saver: Swimming Pool Covers (archived — the live page now returns 404)U.S. Department of Energy via the Internet Archive · read 2026-09-02
- Hands-on solar cover comparison: 4 to 5°F measured in one hour of 2pm sun on 89–92°F days, with the method statedBob Vila · read 2026-09-02
- Solar cover guide: 0.7°F per hour under noontime sun, 10–15°F held, and published lifespan tiers by thicknessSwim University · read 2026-09-02
- Water density: 62.424 pounds per cubic foot at 39.2°FU.S. Geological Survey, Water Science School · read 2026-09-02
- Sun2Solar 459153 listing: 18 ft round, 12 mil blue, stated up to 15°F rise and up to 95% evaporation reduction, supplied oversized with extra overlap to trimSun2Solar, as listed at retail · read 2026-09-20
- Sun2Solar 459004 listing: 16 ft x 32 ft rectangle, 8 mil blue, same stated up to 15°F rise and up to 95% evaporation reductionSun2Solar, as listed at retail · read 2026-09-20
- Blue Wave NS120 listing: 24 ft round, 8 mil blue, 18 lb, 3-year limited manufacturer warranty, and the maker's own storage instruction to roll rather than fold and keep it in the shade when off the poolBlue Wave, as listed at retail · read 2026-09-20
#ad Where a retailer’s listing is cited above as the source of a published specification, that link is an affiliate link, at no extra cost to you. Independent sources and manufacturer documentation are never wrapped and earn nothing. How this site is funded.
Every URL above was fetched and returned content on the date shown. Where a figure is ours rather than somebody else’s, the arithmetic is on the page and on the methodology page. If you find an error in it, we would genuinely like to know.
Read next
Solar covers for kidney, oval and freeform pools
Kidney, oval, freeform and L-shaped pools: when a cut-to-shape cover is worth it, when to buy a rectangle and trim, and how much material each approach wastes.
What size solar cover do I need?
Measuring for round, rectangular, oval and freeform pools, why you buy up rather than exact, and the above-ground nominal-diameter trap that catches people out.
8, 12 or 16 mil: which solar cover thickness
Thickness buys years, not degrees. The published lifespan tiers, the cost per year of service, and the case for 12 mil on a large pool.
Solar pool covers worth buying
Ranked on the specifications that actually differ between covers — thickness tier and published lifespan — because the only hands-on test in this category found no heating difference at all.
Solar cover reels
Why a reel is the highest-leverage buy in pool heating, and which ones to look at. Thirty seconds alone versus five minutes and a helper decides whether a cover saves anything.
Clear vs blue solar covers
Clear transmits into the water, blue absorbs at the surface. Same energy budget either way — and the only published test measured no difference between them.