Measure the air conditioner’s width, depth, and height, then match those numbers to a cover sized for outdoor units.
Buying an air conditioner cover without measuring first is a fast way to waste money on something that either won’t fit or flaps uselessly in the first storm. Whether you’re protecting a window unit or a central outdoor condenser, the process takes roughly two minutes and requires nothing more than a tape measure. The critical details are knowing which side counts as the depth and what to do when your numbers fall between standard cover sizes.
What to Measure on an Outdoor AC Unit
For outdoor condenser units, the official guidance from Frigidaire’s support materials specifies three measurements, each tied to a specific side of the machine. Getting the sides confused is the most common mistake and produces a cover that fits poorly.
Take these three measurements with a metal tape measure, recording each in inches:
- Width: Measure across the side without the wiring and refrigerant piping.
- Depth: Measure across the side with the wiring and piping, as the cover includes openings on this side. This is the measurement people most often get wrong.
- Height: Measure from the ground or pad up to the top of the air conditioner.
Write all three numbers down before you start shopping. Try to take the depth measurement at the widest point of the unit, since the piping connections can add a bit of bulk.
Success sign: You have three numbers in inches labeled width, depth, and height, with depth being the side housing the wiring hookups.
Fitting a Window Air Conditioner
Window units follow a similar logic but sit in a frame, which simplifies the job. You still need the unit’s width to ensure the cover spans the sides, but the depth and height matter less on the exterior portion because the cover grips the frame rather than wrapping the whole machine.
Measure the width of the window unit from one side of its cabinet to the other at the front face, then check the manufacturer’s sizing chart for that specific model. The carrier and installer literature generally lists a compatible cover size right in the product specs, so matching that number directly is the most reliable route.
Most quality covers for window units rely on an elastic hem that grips the bottom of the frame. If the cover is between sizes, you want the slightly larger option that still lets the elastic cinch tight, not one that stretches to its limit.
How to Choose When Your Size Is Unusual
Few air conditioners match a cover size exactly, so the fit guidance from the sources is refreshingly simple: choose a cover that is slightly larger in width and depth rather than smaller. A cover that is a bit roomy still sits stable over the unit, while one that is too tight may not fit over the piping at all or could strain the seams.
As for height, a taller cover is generally fine since most designs are open at the bottom and simply drape down the sides. The danger is only when the cover is so short it leaves the top of the unit exposed to snow and ice.
This matters because it means you cannot simply spin the cover 90 degrees if you misidentified the sides—the openings must line up with your unit’s actual hookups. When you shop, confirm the cover’s cutouts align with the side you measured for depth.
The most important rule: measure the side with the wiring for depth. Cover cutouts are designed to align with that side, so mixing it up with the width means the openings won't line up with your unit's hookups.If you are ready to buy and want a curated list of tested options that fit common unit sizes, our review of the best AC covers narrows down the top picks for various measurements.
Take the measurement again or size up.
FAQs
Do I need to turn off the power before measuring?
No, you do not need to turn off power just to take measurements since you are only using a tape measure on the exterior cabinet. However, you should never remove panels or touch wiring while measuring. If the unit is running, simply measure the exterior sides and avoid the fan grille area.
What tape measure works best for this job?
A standard 25-foot metal tape measure works perfectly because it is rigid enough to hold its shape across the width of a large condenser unit. Fabric sewing tapes can work for smaller window units but tend to sag on wider spans, which leads to inaccurate depth readings.
Should I size up for a cover with insulation?
Not unless the cover manufacturer says to. Insulated covers are built to their listed dimensions just like standard ones, with the insulation inside the fabric layers. Match the cover size to your unit’s measurements exactly, then apply the slightly larger rule only when no exact match exists.
References & Sources
