Choosing the right shower door starts with one thing: accurate measuring. Whether you’re replacing an old door or fitting a brand‑new enclosure, getting the measurements right ensures a watertight fit, smooth installation, and a bathroom that looks professionally finished.
This guide walks you through the exact steps to measure for any type of shower door — recess, alcove, quadrant, walk‑in, or enclosure — using clear, practical instructions you can trust.
Why Measuring Matters
Shower doors aren’t “one size fits all”. Even a few millimetres out can cause:
Leaks and water escaping
Doors that don’t close properly
Misaligned hinges or rollers
Gaps between the wall and the frame
Stress on glass panels
Manufacturers design doors with adjustment ranges (e.g., 760mm door fits 740–780mm), but you still need accurate measurements to choose the right size.
What You’ll Need
Tape measure (rigid metal type is best)
Spirit level
Pencil or notes app
A helper (optional but useful for larger enclosures)
Step‑by‑Step: How to Measure for a Shower Door
1. Measure the Width at Three Points
Walls are rarely perfectly straight — especially in older UK homes. That’s why you should measure the opening at:
Top
Middle
Bottom
Write down all three measurements.
👉 Use the smallest measurement when choosing your door size.
This ensures the door fits even if the walls taper inwards.
2. Check if the Walls Are Out of True
Place a spirit level vertically against each wall.
If the bubble drifts left or right, your walls are out of plumb.
This is normal — and why adjustment ranges exist — but it’s important to know:
Slightly out of true: Most doors can compensate.
Significantly out of true: You may need a wider adjustment range or a framed door for better sealing.
3. Measure the Height
Measure from the top of your shower tray (or floor, for wetrooms) to the height you want the door to reach.
Standard shower door heights include:
1850mm
1900mm
1950mm
2000mm
Higher doors help contain steam and splashes, especially in modern bathrooms with rainfall showers.
Measuring for Different Types of Shower Doors
Recess / Alcove Shower Doors
These fit between two walls.
You need:
Width at top, middle, bottom
Height from tray to desired door height
Wall plumb check
Tip: If your opening varies more than 10mm top‑to‑bottom, choose a door with a generous adjustment range.
Hinged or Pivot Doors
These require space to swing open.
Check:
Width of opening
Clearance outside the shower
Clearance inside (for pivot doors that swing both ways)
Tip: Small bathrooms often benefit from sliding or bi‑fold doors instead.
Sliding Doors
Ideal for tight spaces.
Measure:
Opening width
Tray lip depth (to ensure rollers sit correctly)
Wall alignment
Sliding doors are the most forgiving when walls aren’t perfectly straight.
Bi‑Fold Doors
These fold inward, making them great for compact bathrooms.
Measure:
Opening width
Internal clearance (to ensure the folded panels don’t hit anything)
Quadrant & Offset Quadrant Enclosures
For curved trays, you’ll need:
Tray radius (usually 550mm or 560mm)
Width and depth of the tray
Height from tray to desired door height
Tip: Always match the enclosure to the tray brand and size — curves vary.
Walk‑In Screens
These are the simplest to measure.
You need:
Length of the screen
Height
Space for support arms (if required)
Walk‑ins are ideal for wetrooms or minimalist bathrooms.
Understanding Adjustment Ranges
Most shower doors list an adjustment range, such as:
760mm door (adjusts 740–780mm)
800mm door (adjusts 770–810mm)
This allows the frame to compensate for uneven walls or slight variations in opening size.
👉 Choose the door where your smallest measurement sits comfortably within the adjustment range.
Common Measuring Mistakes to Avoid
Measuring only once
Ignoring wall alignment
Forgetting to measure the tray lip
Assuming your old door was the correct size
Measuring from tile to tile instead of wall to wall
Take your time — accurate measurements save money and hassle.
When to Choose a Different Door Type
If your walls are significantly out of true or your opening varies by more than 15–20mm, consider:
A framed door (more forgiving)
A sliding door (less reliant on perfect alignment)
A door with a larger adjustment range
Need Help Choosing the Right Size?
At Shower Door Store, we specialise in helping customers find the perfect fit. If you’re unsure about your measurements, send them over — we’ll guide you to the right door with no pressure and no jargon.