How to Measure for Bedroom Window Valances? | Get the Right Fit

Measure the window width first, then the drop from the mounting point to the desired hem — a process that takes about five minutes with a tape measure.

For the full breakdown, see our best Bedroom Window Valances guide.

Getting the measurements right for a bedroom window valance comes down to two numbers: the width and the drop. One wrong figure can leave you with a valance that either swims on the rod or leaves bare gaps at the sides of the window. Here’s the practical process that works for most bedroom setups.

The Two Measurements That Matter Most

You need the width of the window or mounting area, then the length from the mounting point down to where you want the fabric to end. For a flat, tailored valance, the measured width is typically the window opening or the rod span, often with about 2 inches added for clearance and overlap. For a gathered style, the finished width commonly runs 1.5 to 2.5 times the installed width, with some guides using up to 3 times for fuller looks.

The drop gets measured from the top of the rod, board, or mounting point down to the chosen hem line. Measuring from the wrong spot — like the floor or the window sill — throws off the entire length. A common proportion rule is that a valance should be about 1/5 to 1/6 of the total window height, which lands most residential windows in the 10-to-18-inch range.

Choosing the Right Mount and Fullness

Your installation type changes the numbers. Decide whether you are doing an inside-mount, outside-mount, rod-mounted, or board-mounted valance before measuring, because the same window can require different dimensions depending on the method. For outside-mount valances, plan to add about 2 to 4 inches per side beyond the window frame for coverage and visual balance.

Inside-mount installations use the inside edge of the casing or the bracket span — just be sure the brackets themselves don’t eat into that space. Valance fullness also depends on the style. A flat valance needs the measured width plus clearance; a gathered or balloon style needs a fuller multiplier applied to that base width. If you intend to mount the valance over blinds or shades, measure the return or depth needed to clear the underlying hardware, or the valance will sit awkwardly or bind.

Step-by-Step Measuring Process

Follow these steps in order and write everything down as you go:

• Measure the window width at the top, where the valance will hang, not at the middle or bottom.
• Decide whether the valance will be flat, pleated, gathered, balloon, rod-pocket, or swagged, since each style changes fullness and final width.
• For gathered styles, multiply the measured width by your fullness factor — commonly 1.5x to 3x depending on the fabric’s weight and the look you want.
• Measure the drop from the mounting point — whether that is the rod, board, or bracket — down to the desired hem position.
• If layering over existing treatments, measure the projection of the blinds or shades to confirm the valance depth clears them.

Once you have these numbers, you’re ready to shop — and our roundup of the best bedroom window valances can point you toward styles that match the look you’re after.

Common Mistakes and What to Watch For

Measuring only the glass instead of the full window opening, casing, or bracket span frequently produces a valance that is too narrow. Forgetting to account for the mounting hardware’s projection can cause the valance to interfere with blinds or shades underneath. Using the wrong fullness multiplier makes a gathered valance look either flat or overly bulky.

One more frequent stumble: measuring the drop from the floor or sill rather than from the rod or board. Top treatments hang from the top of the window, not the bottom, so anchor every length measurement to that mounting point. If you are layering the valance over blinds or shades, verify the return depth of the valance clears the projection of whatever sits behind it before you commit to a style.