How to Measure For Replacement RV WindowsWhen you are measuring for replacement RV windows, it’s critical that you get it right. You don’t want to waste money or become frustrated during the RV window installation.

Before you start measuring, remove the old window from the RV so you can measure the entire window opening.

To ensure a proper fit, follow these steps:

1. Measure the opening

Don’t measure the old window. Measure the rough opening in the wall of your RV. Don’t compare your measurements to the dimensions of the old window; they’re not supposed to be similar.

Get the length and the width of the window opening. Remember to always measure twice and to measure to the nearest 1/16 inch.

2. Measure the sidewall depth

To get the depth of the window opening, stick a stiff ruler through the window opening until it reaches the exterior of the wall. Or measure from the interior wall surface to the exterior wall surface.

Do not include the thickness of the window frame when getting the sidewall depth.

3. Measure the corner radius

radius measurement toolIf your window has square corners, you can skip this step. But if your window has rounded corners, you will need to determine and supply the corner radius when you order your new RV windows. Most rounded corners are about 2.5 or 3 inches in radius.

To get this measurement, you will need to use a compass or print a radius template. Make sure to print it out at full scale.

Hold the template up to one of the corners of the window opening and see which radius is the closest match.

Most RV window manufacturers provide guides and templates on their websites. Use these before you order your new RV windows.

Related: Quick Guide to Standard RV Window Sizes & Setups