How to Measure

How To Measure For A Window Treatment


  • Use a metal measuring tape, never use cloth.
  • Write down all measurements, making sure the width and height are properly labeled.
  • Be accurate. Round measurements down to the nearest one-eighth inch (1/8").
  • Double check all measurements.
  • Measure every window, even if they appear to be the same size.
  • An inside mount refers to blinds that are mounted inside the opening of a window frame. This mount is a very common way to cover windows and furnishes a very clean look. To use an inside mount, the depth of the window frame must be at least two inches (2") deep.
  • An outside mount refers to blinds that are mounted outside the opening of a window frame, either to the wood frame/trim of the window or to a wall. The blinds will overlap the window providing optimal privacy and light blockage. This mount is perfect for windows with a shallow window frame depth. Outside mounted blinds need a flat surface for mounting.
  • Measure the width in three places: top, middle and bottom as shown in Figure 1. For an inside mount, use the shortest width.
  • Measure the height in three different places: left, middle, and right as shown in Figure 1. Use the longest measurement except when measuring for vertical blinds.

Please select a product for measuring instructions:

Wood Cornice Box & Lambrequins or Curtain Panels

For a Wood Cornice/Valance Box, measure the total width, A, of the area to be covered. Typically cornice/valance boxes are 4"-6" wider than the window width.

All cornice/valance box width measurements are based on the overall OUTSIDE measurement. The INSIDE measurement will be approximately 1" less than the OUTSIDE measurement.

If a blind or shade will be mounted inside of the cornice/valance box, the blind or shade should be at least 2" less in width than the overall outside width of the cornice/valance box.

For Lambrequins and Curtain Panels used with Cornice/Valance Boxes, measure from where the inside top of the Cornice/Valance Box will be mounted, B, to the desired length.

Wood Blinds, Mini Blinds, Pleated Shades, & Roller Shades

Inside Mount

Inside Mount

To mount your shade inside of your window frame, your soffit must be at least two inches (2") deep. Measure the opening width, A, in three places: top, middle and bottom (as shown at right). Record the narrowest of the three dimensions.

Measure the height, B, in three places: left, middle, and right and record the largest measurement.  We will make the necessary deductions for proper operating clearances.

Outside Mount

Outside Mount

Measure the total width, C, of the area be covered. Normally 1'' on each side of the glass offers good coverage but you may want to cover the trim or have a limitation on width if mounting inside a valance.  Record this measurement.

All width measurements are based on the head rail width.  Pleated shade fabric is about a 1/4'' narrower than the head rail. Roller shade vinyl is approximately 1'' narrower than the head rail. Mini blind slats are the same width as the head rail.

Measure the height, D, of the area to be covered. Normally 1'' on the top and 1'' on the bottom of the glass offers good coverage, but you may want to cover trim or mount higher to accommodate mounting into the top of a hard valance or under a cabinet. Record this measurement.  All height measurements are from the top of the head rail to the bottom of the bottom rail on all products.

Measuring for Inside a Cornice / Valance Box

If you are ADDING a blind or shade to be installed inside a cornice/valance box, make sure that the blind or shade you order is at least 1'' narrower in width, than the INSIDE measurement of the cornice/valance box.

If you are REPLACING an existing blind or shade that has been mounted inside of a cornice/valance box, measure the width of the top rail of the blind or shade you are replacing, and provide us with that measurement, along with the overall height you need for the blind or shade.

Vertical Blinds

Vertical Blinds

Measure the desired width, C, where the headrail will be installed. The width must overlap the door or window by at least four inches (4") on each side to ensure privacy and proper stacking of the blinds when open. Record this measurement.

Measure the height, D, of the window in three places: left, center, and right. Take the smallest of these measurements and record it. Or if you desire a floor length vertical, measure to 1'' above the floor.

Draperies & Curtains


Measure the desired width, A, where the rod will be installed.

Measure the length from the rod to the place you would like your draperies to hang. The rod should be at least four inches (4") above the window. Measure the height, B, if you want a windowsill-length drapery. Measure the height, C, if you want a an apron-length drapery. Or, measure the height, D, to 1'' above the floor if you desire a floor length drapery. Record this measurement.

Pleated Accordion Door

Measure the width of the opening. (opening width)

Measure the height from the top mounting location to the bottom of the door fabric. (door height)

Make sure you allow for clearance of the floor and floor covering which is normally 2''.

The overall measurement that you provide will include the track, hangers, and pleated fabric.