Skimmer Equipment /
How Do You Measure a Skimmer Lid Before Ordering a New One?
Measure the skimmer lid itself, confirm the opening and frame, and match brand details so the new cover fits securely, sits flush, and stays safe.
Archive date: this article was written for PoolSkimmer on Oct 7, 2026 and given the earlier archive date of Sep 15, 2026 so the blog reads as an organized archive. It was not published on that date.
Start by determining the skimmer lid type
Your first step is to get a good look at the skimmer lid and cover style before any measuring is done. You will find that pool skimmer lids are not all made alike; they can be round, square or rectangular, with different lip designs and locking tabs. Some sit level with the deck while others stick up a bit.
Examine the lid, frame or skimmer body for any molded markings. A part number or brand like Hayward, Pentair or Sta-Rite will make it easier to source a replacement that is compatible. Should the original be an inlay style or part of a special cover kit, make a note of it prior to ordering.
Put the tape measure on the lid, not the opening
While you might be tempted to measure the pool opening, that figure can be deceptive. The lid itself is what matters. Two covers may go over the same opening but have entirely different depths or edge profiles.
With a ruler or tape measure, take down the following:
- For a round lid, the diameter; for square or rectangular ones, the outside length and width
- The overall thickness and depth
- The height of any rim, flange or lip on the bottom side
- Spacing for screws, slots or tabs if there is a retainer
It is wise to measure in more than one direction. If the existing cover has become sun-brittle or is warped, check several spots and record the extremes. This way you do not end up with a replacement that is close enough in size but still rocks when you put weight on it.
Verify the frame and opening
Once the lid is measured, turn your attention to the skimmer opening and frame to be sure the new piece will support foot traffic from the patio and sit flush. Note the inside size of the skimmer, the ledge it rests on, and the depth to the top surface, as well as any grooves or ridges. An older skimmer box may have a frame that is not quite square, which is why a standard cover might appear to fit but will not be secure.
Stick with the original brand and model where you can
Do not assume a skimmer lid is universal. Even if a cover appears to be an interchangeable option, the support profile may be off. It is best to match the make and model of the original.
In the absence of the old cover, look for a stamped code or embossed lettering on the skimmer body. Good photos are useful too, particularly when comparing to a specific kit being sold. And when a vendor claims compatibility with a Pentair or Hayward model, verify the dimensions rather than just going by the name.
Pitfalls to steer clear of
A near-match is often a poor one. To avoid a loose fitting cover that could let in debris or become a tripping hazard, do not:
- Measure only the top and overlook the underside
- Make the mistake of equating the skimmer opening with the lid size
- Try to force a round lid into a rectangular frame
- Neglect the flange height and depth
- Pick a cover that leaves a gap or is prone to tipping
Precautions for removing the cover
Before you lift a loose lid or open the skimmer area near the waterline, shut off the pump. Adhere to the instructions from the manufacturer and the equipment manual. Wear eye protection and gloves as PPE if the lid is in rough shape. Under no circumstances should you work on suction fittings with the pump running or put your hands in operating equipment.
If you come across a cracked housing, broken plumbing, a shifting deck or an electrical issue of any kind, put the work aside and contact a pro.
Know when to leave it to the experts
You may want to call in a qualified pool professional if:
- There are no markings on the cover to confirm its size
- The frame is uneven or cracked
- You are dealing with a nonstandard inlay or suspect hidden leaks and structural movement
- There are any electrical concerns in the vicinity of the pool gear
Taking the time to measure with care will mean a skimmer lid that is snug and secure, and spare you the trouble of returns or unsafe makeshift repairs down the road.