How to fit a hot tub cover
Updated: October 2026
A parcel that looked right on a 4 person title is the usual way a hot tub cover comes back, or splits on the way on. You need three numbers before you order: length, width and the drop of the skirt, in centimetres. This is how to fit a cap over a lid you already have, which differs from measuring a new rigid lid. The twelve listings on the [hot tub cover comparison](/hub/steam-baths/hot-tub-cover) include size fields of 5 cm and 23 × 6 cm that you should not average. We did not visit your garden. Links to amazon.co.uk can earn a commission if you buy.
A parcel that looked right on a 4 person title is the usual way a hot tub cover comes back, or splits on the way on. You need three numbers before you order: length, width and the drop of the skirt, in centimetres.
A parcel that looked right on a 4 person title is the usual way a hot tub cover comes back, or splits on the way on. You need three numbers before you order: length, width and the drop of the skirt, in centimetres. This is how to fit a cap over a lid you already have, which differs from measuring a new rigid lid. The twelve listings on the hot tub cover comparison include size fields of 5 cm and 23 × 6 cm that you should not average. We did not visit your garden. Links to amazon.co.uk can earn a commission if you buy.
Our top picks
| Badge | Product | Stated size | Fastening | Shape | Note | Price | Offer |
|---|---|---|---|---|---|---|---|
| Best overall |  ULTCOVER ULTCOVER 600D cap, 80 × 80 inch | Up to 80×80 in; item 2.03×2.03 m; height 20 in | Pull closure and elastic cords | Square | 9.2 | about £57.82 | View offer |
| Best value |  dDanke dDanke square PE cover, 200×200×85 cm | 200×200×85 cm; bullets also 220 and 240 cm | Drawstring | Square | 8.4 | about £21.00 | View offer |
| Alternative |  SHATCHI SHATCHI inflatable lid, 160 cm | 160 cm for tubs up to 173 cm | Pull on | Round | 8.2 | about £18.99 | View offer |
On this page
Measure the shell, not the guess
Hot Tubs UK’s measuring FAQ tells you to measure the shell, or a cover that still fits, and says a cover that is too small never seals. A bit too big is their preference. TopTubs says not to measure a warped old cover, because the sag copies the failure into the new order. Hydrospares tells you to take the widest acrylic edge in both directions and the corner radius with a square. Those guides are written for rigid lids. Which object you need is on the buying guide.
If length and width differ, write both. For a rigid lid, round the corner radius down rather than up, so the new cover is not proud of a tight radius. Hydrospares allows about 12 mm of clearance. Do not add a universal 5 cm. A 200 × 200 cm dDanke sheet on a true 2 m tub had no spare. A YUJHON review of a much larger size on a 205 × 205 cm tub found the cover too roomy. The bullet’s own rule is a cover slightly larger than the spa, such as 215 cm of cloth for a spa up to 210 cm.
A cap is measured over the lid you already have
A cap’s advertised size is the outside of the thing it must swallow, plus the skirt. Measure across the lid in both directions, then from the top down to where you want the hem to finish. The listings use that drop as the third number: 85 cm and 90 cm on the square caps, 70 cm and 72 cm on the round ones, and 20 inches of height on the ULTCOVER 80 inch size field. If you measure only the cabinet and ignore a thick lid, the hem finishes on the vinyl instead of under the lip.
Put the cap on with the lid closed and locked, if the lid still locks. A drawstring, which is the dDanke closure, needs the hem gathered before you pull. Elastic cords, on the ULTCOVER, hook under the lip. The 85 inch ULTCOVER field says hook-and-loop while the bullets still say elastic cords, so look at the cover in your hands. None of these is a keyed lock. If the cloth will not reach without tearing, stop. A 420D review describes a split while a cover was forced onto a Lay-Z-Spa Vegas. Whether a cap can stand in for the lid is on hard cover or cover cap.
Round tubs and the pump beside them
For a round inflatable, measure the diameter across the top ring, not the water, and measure the drop from that ring to where the hem must pass. A Lay-Z-Spa Miami review on the 190 × 70 cm GIONAR page says the cloth covered the tub and left the heater and pump standing outside. If your pump housing sits outside the ring, no round cap in this set claims to cover it. Do not size up a tub cover in the hope that 215 cm of cloth will become a pump tent.
The SHATCHI bladder is the one listing that is not a skirt. It is about 160 cm, claimed for tubs up to 173 cm, and it floats on the water. The bullets do not say a pump is included. Reviewers say it loses air within a few days, so fitted includes a weekly top-up. One review says it will not stop rain pooling on top, because the bladder is in the water. A 6 person GIONAR at 215 × 70 cm and a 4 person GIONAR at 190 × 70 cm are different cuts. The number of people is not on your tape.
Fields you should not average
When two numbers disagree, do not split the difference. The GIONAR 190 × 70 cm polyethylene page has a size field of 5 cm. That field is unusable. The WGFOIP title says 210 × 210 × 30 cm, and the item dimensions say 23 × 6 cm. There is no honest average of 210 cm and 23 cm. The Gemsaya item weight of 100 g on a 200 × 72 cm cover is the same kind of broken field.
The dDanke bullet names 200, 220 and 240 cm in one place. Order the cut that matches your paper. The ULTCOVER pages are cleaner: up to 80 × 80 inches, with item dimensions of 2.03 × 2.03 m, or up to 85 × 85 inches with a 216 × 216 cm field. Even there, up to means your lid must be smaller than the cap. The best hot tub cover page is for choosing among these listings once the centimetres are written down.
Common questions
Do I measure the shell or the old cover?
For a new rigid lid, Hot Tubs UK says the shell, or a cover that still fits. TopTubs says do not measure a warped lid, because the sag is not the shape you want to copy. For a cap, measure the outside of the lid that is on the tub now, including the drop.
What is the skirt or the drop?
The skirt is the part that hangs down the side. On these listings it is the third figure: 85 cm or 90 cm on several square caps, 70 cm or 72 cm on the round pages, and 20 inches on the ULTCOVER 80 inch size line. A diameter without a drop is how a round cover blows off.
How do I measure a round inflatable?
Across the top ring, not across the water, and then the drop down the side. Compare that with 190 × 70 cm, 200 × 72 cm or 215 × 70 cm. Leave the external pump out of the diameter. The SHATCHI goes on the water, not around the cabinet.
What if length and width differ on a square tub?
Write both. Order a cap that is larger than the longer side. The YUJHON bullet says the 215 cm cover is for spas up to 210 cm. A review of a much larger size on a 205 cm tub found it too roomy, so larger means a small margin, not the next size class.
What do I do with a corner radius?
For a rigid lid, take the radius with a square, as Hydrospares describes, and round it down, as Hot Tubs UK says. Hydrospares’ clearance is about 12 mm. A textile cap does not need a radius cut. It needs enough cloth to pass the corner without a tear.
How tight should the hem be?
Tight enough that a lifted corner does not walk off in the wind you actually get. Reviews of the dDanke and the Rocita say a cord alone can still leave the sheet loose. If the only way on is to tear the cloth, as on the Vegas review, the cover is the wrong size.
Related pages
Sources
Public UK sources used for this comparison. Listing prices, stars and review counts are the amazon.co.uk figures saved for this set on 19 October 2026.
- RoSPA, hot tub water safety (retrieved 19 October 2026)
- RLSS UK, splash safely around hot tubs (retrieved 19 October 2026)
- BISHTA, be water aware (retrieved 19 October 2026)
- BSI, BS EN 17125:2018 domestic spas (retrieved 19 October 2026)
- Hot Tubs UK, replacement hot tub covers (retrieved 19 October 2026)
- Hydrospares, how to measure a hot tub cover (retrieved 19 October 2026)
- Covers for Tubs, FAQ (retrieved 19 October 2026)
- Consumer Rights Act 2015, section 11 (retrieved 19 October 2026)