How To Measure Windows

When ordering windows it’s important to know what size windows you will need. Having the correct measurements for your windows can save you from making costly mistakes when ordering. Here is a step-by-step process on how to measure your windows.

When measuring your windows it’s good to know what your measuring, so your not measuring the wrong parts. Here are some general terms to get you up to speed, so you can start measuring.

FRAME

The window frame surrounds and supports the entire window. This includes the head, jamb, and sill.

JAMBS

Jambs are the vertical parts that form the sides of the window frame.

HEAD

The window head is the main horizontal part that forms the top of the window frame.

STILL

This refers to the central horizontal part that forms the bottom of the window frame. It’s the area where the window sash rests when it’s closed, not the horizontal board that extends from the wall.

SASH

This is the movable part of a window that holds the glass.

How to Measure Home Windows

Below are three simple steps you can take to measure your windows correctly.

Step 1: Measure the Width

Using your measuring tape, measure the distance between the jambs at the top, middle, and bottom of the window. Make sure to measure from the surface of the jambs and not from the outer moldings, such as trim strips or parting beads. Use the smallest of the three width measurements to order your window.

Step 2: Measure the Height

Using the surface closest to the inside of the window, measure from the high point of your window sill to the top of the window opening. Measure from the left side, the center, and the right side of the window. Again, use the smallest of these three height measurements to order the window.

Step 3: Measure Depth

Measure the window edge-to-edge from the outside of the frame to the inside. Do this in several locations around the window frame and use the smallest measurement. It should be a minimum of three-and-one-fourth inches to properly fit a replacement window. Otherwise, you may need additional materials to fill the gap. This is typically the most accurate measurement of depth.

Another option is to measure the depth on each side of the glass and add the two numbers together. An installer will remove any pulleys or parting strips (or the vertical strips between the window sashes), so ignore those while measuring.

How To Measure Windows