How to Measure Your Shower Opening for a Glass Door
By Direct Shower Door · October 2, 2026 · 7 min read
You do not need to measure your shower to get a frameless door. We measure every opening precisely in your home before any glass is cut, and that measurement is the one the glass is made from. But taking your own measurements first is still worth five minutes, because the numbers tell you a lot about which styles will fit, whether your walls are square, and what to ask about when we visit.
This guide shows you how to measure properly, what each measurement means, and how to read the results. There is a helper below that turns your tape measure readings into the numbers that matter.
The short answer
Measure the width at the top, middle and bottom, and the height on both sides.
The narrowest width is the working width. Differences show whether the walls are out of plumb.
Note anything that will affect the glass: a curb, a bench, a knee wall, a slope in the floor, tile that is not finished yet.
What You Need
A steel tape measure (not a cloth one).
A pencil and paper, or your phone.
A level, if you have one.
Five minutes.
Step 1: Measure the Width Three Times
Measure across the opening, wall to wall, at three heights: near the top of where the glass will go, at the middle, and at the bottom just above the curb or floor. Measure from finished tile to finished tile.
Why three? Walls are rarely perfectly straight or plumb. A wall can lean in or out by a quarter of an inch or more over its height, especially in older homes or where tile has been laid over uneven backing. Frameless glass is cut to the measured opening, so knowing how the width varies matters.
Step 2: Measure the Height on Both Sides
Measure from the top of the curb or the shower floor to where you want the glass to stop, on the left and the right. Most enclosures stop somewhere below the ceiling; a steam enclosure runs to the ceiling. If the two heights differ, your curb or floor slopes, which is normal: showers are built to drain.
Step 3: Note the Details
Curb: its height and width, and whether its top slopes toward the shower.
Bench or knee wall: glass may need a notch to fit around it, which the door and notch panel style is designed for.
Shower head and controls: where they are, and which way the head points.
What is in front of the shower: the clear floor before the toilet or vanity, which decides whether a door can swing.
Tile status: if tile is not finished yet, wait. Glass is measured to finished surfaces. See our guide on when to order during a remodel.
Turn Your Measurements Into a Plan
Enter what you measured. The helper shows your working width, flags out-of-plumb walls and sloping curbs, and points out width ranges that suit particular styles. You can copy the summary to mention when you book.
◆ Measuring Helper
Turn your tape measure readings into a plan
Enter your measurements to see the numbers that matter.
Your numbers help you plan and compare styles. Before any glass is cut, we measure the opening precisely in your home.
Reading Your Results
Working width
The narrowest of your three widths is the one that counts, since the glass has to fit through the tightest point. A rough guide to how width shapes style:
Under about 36 inches: a single hinged frameless door often covers the whole opening, if it has room to swing.
Over 60 inches: sliders, bypass doors or a door with one or more fixed panels.
These are general guides, not rules. We confirm the right configuration at your measure.
Out-of-plumb walls
If your widths differ by more than about a quarter of an inch, your walls are out of plumb. That is common, and it is exactly why frameless glass is custom cut rather than bought in standard sizes. Mention it when you book so we expect it.
Sloped curbs and floors
A difference between left and right heights means the curb or floor slopes. Again, normal and expected. The glass and sweep are fitted to it.
Clear floor in front
If the shower has less clear floor in front than the width of a door, a hinged door will struggle. Our small bathroom guide has a clearance check and the styles that work instead.
Why We Still Measure Ourselves
Frameless glass is unforgiving of small errors, because there is no frame to hide a gap. Our measure uses precise tools, checks the walls for plumb and square, notes the exact curb profile and any obstructions, and plans the hardware positions. That measurement is what your glass is cut to. Your own numbers help you plan and compare styles; ours make the glass fit.
An Example, Worked Through
Here is how a typical set of readings might look for an alcove shower:
Reading
Measured
What it tells you
Width at top
48 1/2″
A 1/2″ difference: the walls are slightly out of plumb, which is common. The working width is 48″.
Width at middle
48 1/4″
Width at bottom
48″
Height, left
72″
The curb slopes slightly, as it should for drainage.
Height, right
71 3/4″
Clear floor in front
26″
Tight for a wide hinged door. A door and inline panel or a slider would suit.
With a working width of 48 inches and limited swing room, we would probably suggest a door and inline panel with a narrower door, or a frameless slider. We would confirm at the measure.
Measuring Other Shower Types
Tub with a shower
Measure the width across the tub deck from wall to wall at the deck, middle and top, and the height from the tub deck to where you want the glass to stop. Note whether the tub deck is flat or has a lip. See our bypass doors guide.
Corner shower
Measure each side of the opening separately along the curb, plus the height at each wall. For a neoangle, measure all three front segments and note the angle of the base.
Walk-in shower
Measure the length of the shower, the width, where the shower head is, and the width of the opening you want. That tells you whether a splash panel will keep water in.
Common Measuring Mistakes
Measuring to the old frame. If an old framed door is still in place, measure wall to wall, not to the inside of the frame.
Measuring before tile. The finished opening is smaller by the thickness of the tile and setting bed.
Rounding. Write down the exact eighth of an inch. Small differences matter on frameless glass.
Using a cloth tape. It stretches. Use a steel tape.
Forgetting obstructions. Grab bars, soap niches near the edge, and the shower valve can all affect where hardware goes.
Photos That Help When You Book
Along with your measurements, a few photos help us prepare for the visit:
The whole shower, straight on, from the bathroom doorway.
Each side wall where the glass will meet it.
The curb or tub edge, close up.
Anything unusual: a bench, a niche near the edge, a window in the shower, a sloped ceiling.
The floor in front of the shower, showing the toilet and vanity.
Measuring for a Replacement vs. a Remodel
Replacing an existing enclosure
Measure wall to wall and curb to the height you want, ignoring the old frame. When the old enclosure comes out there may be holes or marks in the tile where it was fixed. New hardware can often cover them, and we will talk you through it at the measure.
New shower in a remodel
Wait for finished tile, including the curb cap and any trim pieces at the edge of the opening. Even the edge trim changes the opening by a fraction of an inch, and frameless glass is cut to fit exactly. See when to order glass during a remodel.
Frequently Asked Questions
Do I need to measure before I call?
No. It is helpful for planning, but we measure precisely in your home before anything is ordered.
Should I measure before the tile is finished?
No. Glass is measured to finished tile. Measuring early risks glass that does not fit.
My walls are not straight. Is that a problem?
No. Most walls are not perfectly plumb. Custom-cut frameless glass is made to fit the actual opening.
How precise do my measurements need to be?
For planning, to the nearest eighth of an inch is plenty. The measurement the glass is made from is taken by us.
What if my curb is not level?
Very few are. The glass and sweep are fitted to the actual curb.
When to Order Your Shower Door During a Bathroom Remodel
Remodelling a bathroom? Learn when to choose your shower door style, when to book the glass measure, what to tell your contractor, and how to avoid delays at the end of the job.
How Long Does Shower Door Installation Take? The Full Timeline
How long does shower door installation take? See each step from free quote to finished shower, what affects lead time, how to prepare, and how 3-Day Rush Service works.
Get an exact shower door price free, often over the phone the same day, then an in-home measure with samples. What to tell us, what we check, and how to prepare.