How to Measure a Shower Door
Why this matters:
If you give us the wrong measurements, your new shower door won’t fit.
And because glass doors are made to order, we can’t take them back.
Follow these steps carefully. You only need a tape measure, a pencil, and 5 minutes.
1. What to measure — and what NOT to measure
✅ Measure the finished opening
That means: tile to tile, or acrylic wall to acrylic wall.
Measure after your walls are fully installed.
❌ Do NOT include accent border tile
If you have decorative tile strips that stick out, measure past them.
Otherwise, the door frame will hit the bump and won’t sit flat.
2. Two different wall types = two different formulas
Your shower walls are either:
| Wall Type | Common in | How much to subtract |
|---|---|---|
| Acrylic (one-piece or panels) | Apartments, prefab showers | 1 to 1½ inches per wall |
| Ceramic tile over cement board | Most homes, custom showers | ¾ to 1 inch per wall |
💡 Why subtract?
You’re measuring from stud to stud (behind the wall).
Then you remove the thickness of both walls to get the true door opening.
3. How ceramic wall thickness adds up (real numbers)
If you have ceramic tile, here’s what’s behind it:
-
Drywall / gypsum board: ½ to ⅝ inch
-
Cement backer board: ⅛ to ¼ inch
-
Ceramic tile itself: ⅛ to ⁵⁄₁₆ inch
Total per wall: roughly ¾ to 1 inch
That’s why we use that range.
4. Simple step-by-step measurement (no math panic)
A, B, C = width from wall to wall at top, middle, and bottom.
D = height from the top of the base to the top of the wall.
Note: The door includes a small adjustment range to allow for minor width variations.
Step 1 – Measure stud to stud
Find the two wall studs on either side of your opening. Measure between them.
Step 2 – Identify your wall type
Acrylic or ceramic? (See table above)
Step 3 – Subtract both walls
Example for ceramic walls:
-
Stud-to-stud = 60 inches
-
Subtract ¾ inch (left wall) + ¾ inch (right wall) = 1½ inches total
-
Final opening width = 58½ inches
Step 4 – Order that final number
That’s the door size you need.
5. Quick cheat sheet for common sizes
| Stud-to-stud width | Acrylic walls (subtract 2–3″ total) | Ceramic walls (subtract 1.5–2″ total) |
|---|---|---|
| 60″ | 57–58″ | 58–58.5″ |
| 58″ | 55–56″ | 56–56.5″ |
| 54″ | 51–52″ | 52–52.5″ |
Always round down if you’re between sizes. A slightly smaller door can be adjusted. A bigger door cannot.
One last rule (save yourself a headache)
Measure twice. Order once.
If your opening isn’t perfectly square (most aren’t), use the smallest measurement.
When in doubt: take photos of your tape measure on the wall and email us. We’ll check your numbers before you buy.