A valance that fits well starts with measuring width, drop, and clearance for your window’s proportions and hardware, then matching fullness and style to your window treatment type.
Valances cover only the top portion of a window — typically 10 to 18 inches — making them ideal for hiding hardware, adding a decorative layer, or topping blinds without blocking natural light. Choosing one resolves three decisions: what the valance sits over (blinds, shades, drapes, or nothing), window width and depth, and style. Accuracy comes from measuring before ordering, not guessing.
Start With Function: Standalone or Layered?
The first question determines width and mounting. A standalone valance needs more width and side coverage than one layered over curtains. A valance over blinds needs enough return depth — the space between wall and valance back — so it doesn’t jam the blind’s tilt mechanism or pull cord. This depth check matters most for inside-mount installations: you need at least 1½ inches of unobstructed depth for some flat valances, plus clearance for brackets and blind operation. For layering over existing coverings, account for curtain stacking room on each side. Our tested roundup of bathroom window valances covers styles sized for bathroom clearance and humidity constraints.
The Measuring Rules That Actually Matter
Use a metal tape measure — cloth tapes stretch. Measure the window’s inside width at top, middle, and bottom; use the widest for an inside-mount flat valance. For outside mount, measure the full opening including casing and trim, then add 2 to 4 inches per side for simple styles, or 4 inches per side for a taller-window effect. Check return depth — the horizontal board or bracket depth behind the valance — especially if blinds sit underneath. Drop height follows proportion: roughly ⅕ to ⅙ of total window height, or 12 to 18 inches for standard windows. Another formula says 15% to 18% of undertreatment height. For a 60-inch window, a 10-to-12-inch valance looks balanced; kitchens often run shorter due to counters below. Wide windows can take deeper valances; small ones need shorter proportions.
Width, Fullness, Mounting: The Practical Per-Window Table
| Valance Type | Width Rule | Mount Tips |
|---|---|---|
| Simple/flat valance, inside mount | Use the widest inside width; subtract ⅛ to ½ inch for order width | Only if window depth is ≥1½ inches |
| Simple/flat valance, outside mount | 1 to 5 inches wider than window opening | Add 2–4 inches per side for overlap |
| Gathered/ruffled valance | 2 to 3.5 times the window or rod width | Unlined fabrics need up to 3.5x; lined can use 2x |
| Board-mounted (fabric over a wood board) | Board width = window width + returns (usually 3–4 inches each side) | Return depth matters; measure from wall to blind front |
| Valance over blinds/shades | Same as base window width plus clearance for blind brackets | Check unobstructed depth AND tilt-cord clearance |
| Valance over curtains/drapes | Add curtain stacking width on each side | Valance should be same rod or slightly wider |
| Gathered, 3x fullness minimum | 3.5x window width for sheer or unlined | Test rod length: rod must extend past window |
Mount the valance 2 to 6 inches above the window frame for visual balance. Installing too low reduces the illusion of ceiling height and can block light from the window’s top.
Common Sizing Mistakes and How to Avoid Them
The most frequent error is measuring only the glass and ignoring casing and trim — making the valance look too narrow. The second is choosing a drop too short (looks like an afterthought) or too deep (blocks daylight and feels heavy). The third is forgetting return depth or bracket clearance over blinds, which can force a return on a custom-size valance. Use a metal tape measure, check all three dimensions — width, drop, depth — and confirm hardware clearance with manufacturer specs before ordering.
How High Should You Mount the Valance?
Mount 2 to 6 inches above the window frame, not at the frame’s top edge. This creates a taller window illusion and leaves room for brackets. If layering over blinds, check the hardware clears the blind’s top rail and tilt mechanism before drilling.
FAQs
Can a valance be used alone without blinds or curtains?
Yes. A standalone valance needs more width and side overlap than a layered one — typically 2 to 5 inches wider than the window opening, and more for gathered styles. It covers the top third of the window while leaving the rest open.
What is the standard valance length for a kitchen window?
Kitchen valances commonly run 10 to 12 inches drop height due to counters and sinks below. A 36-to-48-inch-wide kitchen window typically takes a 10-to-12-inch valance, but measure total height and apply the ⅕-to-⅙ proportion.
Do valances need to match curtain colors?
No — valances can match, contrast, or complement. A valance in a coordinating fabric that picks up one accent color from the room ties the treatment together without being identical to curtains. Layered valances over blinds often work best when the fabric picks up a room color rather than the blinds.
References & Sources
- Fabritec Design. “Measuring for Valances.” Manufacturer PDF covering inside-mount and outside-mount flat valance measuring steps, including return depth and bracket clearance.
- Window Digest. “How Long Should a Valance Be?” Detailed guide on valance drop proportion (⅕ to ⅙ of window height, 12 to 18 inch ranges, 15%–18% formula).
- Anady Top. “Valance Size Guide.” Retailer guide on width multiples for gathered valances (1.5x to 3.5x) and outside-mount side overlap allowances (2–4 inches per side).