How to Measure a Caravan Window Cut-Out

Replacing or fitting caravan windows isn’t difficult, but it starts with one step you can’t overlook: getting the cut-out size right. A mis-measured window can lead to leaks, rattles, or ordering the wrong product. This guide shows exactly how to measure a caravan window cut-out so you can order with confidence.

What is a Caravan Window Cut-Out?

The cut-out is the raw opening in the caravan wall where the window frame sits. Unlike the overall frame size, the cut-out measurement is the true size of the hole in the wall. Suppliers base their sizing on this cut-out, so it’s the number you must get right.

Step 1: Expose the Opening

• Remove the inner frame screws from the existing window.
• Gently push the window unit out from the inside.
• Clean off any sealant or butyl tape around the opening.

You should now see the raw cut-out in the panel.

Step 2: Measure the Opening, Not the Frame

• Measure the width across the top, middle, and bottom.
• Measure the height on the left, centre, and right.
• Caravan walls aren’t always perfectly square, so take multiple points.
• Record the smallest width and height as your true cut-out size.

Step 3: Record in Millimetres

• Caravan window sizing is in millimetres.
• A “550 × 700” window means a 550 mm high × 700 mm wide cut-out.
• The overall frame will be larger, but the cut-out is what matters for ordering.

TIP: Allow around 2mm clearance all round so if you order one of our SJRV windows and it is 800 x 1000 (that's 800 high x 1000 wide) aim to have the cutout at 802mm x 1002mm and this will allow for slight variations as well as wiggle room to seat the window level.

Step 4: Check Wall Thickness

• Measure the wall depth at the cut-out. Common sizes are 25 mm, 30 mm, or 45 mm.
• Choose a window kit that matches the wall thickness so the inner frame clamps correctly.

Step 5: Confirm Before Ordering

• Measure twice and write the numbers down.
• If you’re between sizes, ask your supplier about trims, fillers, or custom options.
• Ordering slightly too small is usually easier to manage than too large.

Tips & Common Mistakes

• Don’t measure the glass or acrylic pane.
• Don’t round off your measurements.
• Take a clear photo of the opening with a tape measure visible.
• Check for obstructions behind the wall before enlarging any opening.

Why Accurate Measurement Matters

A correct cut-out means a clean, watertight fit, less chance of rattles, and no headaches with returns or freight back-and-forth. It’s the quickest way to a pro finish.

Next step
Once you’ve confirmed your cut-out size and wall thickness, choose a window that matches. We stock a wide range of caravan windows with integrated blinds and flyscreens in multiple sizes, designed for easy installation and Australian conditions.

Shop caravan windows with blinds & flyscreens at VanDIY