Measuring a window opening for furniture is different from measuring a door. The usable opening depends on the window type, whether the sash is in place, and whether exterior obstructions (screens, locks, limiters) reduce the clearance. Getting these measurements right determines whether your furniture can go through the window - or whether you need a different route.
Before measuring, identify what type of window you have. Double-hung windows (two sliding sashes) are the most common in US homes. Casement windows have a crank and swing outward. Sliding windows move horizontally. The type determines how the window opens and what your usable opening will be. If you are not sure, look for a crank handle (casement), sash locks at the top of the bottom sash (double-hung), or a horizontal track (sliding).
If the opening with the sash in place is too small, measure what you would get with the sash removed. On a double-hung window, removing the sash converts the half-height opening into the full frame opening — typically doubling the usable height. Measure the full frame opening from the sill to the head jamb (top of the frame), and from jamb to jamb (left to right), subtracting the track width on each side (0.5 to 1 inch per side). This is your maximum possible opening.
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Raise the bottom sash fully. Measure the width from jamb to jamb at the narrowest point (subtract track width on each side). Measure the height from the sill to the bottom of the raised sash. This is your usable opening with the sash in place. For maximum opening, remove the sash and measure the full frame height from sill to head jamb.
01The screen frame reduces the clear opening by 0.5 to 1 inch on each side. Always remove the screen before final measurements and before moving furniture. Most modern screens have spring-loaded tabs that release from the inside — no tools needed.
02On a double-hung window, removing the sash typically doubles the usable height — from about 50% of the frame height to the full frame height. For a standard 48-inch-tall double-hung, the opening goes from approximately 22 inches (sash up) to approximately 46 inches (sash removed). Width stays the same.
03Opening limiters (child safety stops) restrict the window to about 4 inches. Look for a button, clip, or set screw on the window track. Press the release button or loosen the set screw to allow full opening. Remember to re-engage the limiter after the move, especially in homes with children.
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