Direct answer
Measuring for an automatic cover means measuring the system, not the water: the length and spacing of the track lines, whether the pool is square, the space available for the housing or vault, every obstruction along the track path, and the elevations of coping and deck. Recorded in that form, the numbers support a real quote instead of a revisit.
Key takeaways
- The cover spans the track lines, so track length and spacing are the primary dimensions, not the waterline.
- Diagonals reveal whether the pool is actually square; out-of-square pools are common and must be declared.
- Housing space, obstructions, and elevation changes decide feasibility as much as length and width do.
- Measurements belong on a labeled sketch with photos, in the same document as the coordination checklist.
Cover quotes go wrong at the tape measure. Owners send the pool’s size. Installers need the system’s size, and the two differ by track geometry, housing space, and every obstruction in between. This guide covers what a useful measurement package contains, whether you are sizing a retrofit or checking a new-construction plan from the covers hub.
Measure the system, not the water
- Track length. Measure from the housing end to the far end, along the line each track will actually run. On undertrack systems that follows the coping. On deck-track systems it lies outside the waterline. The families are compared in track types.
- Track spacing. This is the width between track lines. It sets fabric width, which sizes the drum, which sizes the vault or housing. That chain is in the vault guide.
- The square check. Measure both diagonals of the track rectangle. Equal means square. Unequal means skew the installer must plan for. This check prevents the most common retrofit surprise.
- Housing space. Record depth, width, and height available at the mechanism end (vault interior on a new build, bench or housing footprint on a retrofit), plus where its drain and power can come from.
- Elevations. Note coping thickness, deck level changes, and raised walls or spa edges along the track path. Systems tolerate some of this. All of it must be declared.
- Obstructions. Rails, ladders, jets, slides, planters, boulders: photograph each with a tape in frame, and mark them on the sketch.
Record it like a professional
A measurement package that gets a real quote has three parts: a labeled sketch (plan view, track lines drawn, dimensions on the lines, north arrow if sun matters), photos (each end, each side, each obstruction, the housing area), and the numbers written on the sketch rather than in prose. Put the whole package into the cover coordination checklist so measurement, decisions, and sign-offs travel as one document.
Where your tape measure’s job ends
Good owner measurements make quotes accurate and conversations short. The ordered system is still manufactured from the installer’s or manufacturer’s own verified measurement, and that responsibility should stay with them. Your package’s job is to make their visit a confirmation rather than a first look at the site.
Frequently asked questions
Why not just send the pool's length and width?
Because the fabric rides on tracks, and the tracks sit outside or under the edge depending on the system. Two pools with identical waterlines can need different fabric widths and drum sizes. Installers quote from track geometry, so measuring anything else just schedules a second visit.
How do I check whether the pool is square?
Measure both diagonals of the rectangle the tracks will form. Equal diagonals mean square; a difference means the cover must absorb the skew, which the installer needs to know in advance. On existing pools a small skew is normal and manageable when declared, and a surprise when not.
What counts as an obstruction?
Anything the track or fabric path meets - ladders and rails, raised walls or spas, deck jets, slides, planters, boulders, and elevation steps in coping or deck. Each one is either relocated, engineered around, or accepted as a limit. Photograph everything and let the installer decide which.
Sources
- Standards and codes — Pool & Hot Tub Alliance Accessed August 27, 2026.
- Pool Safely campaign resources — U.S. Consumer Product Safety Commission Accessed August 27, 2026.