How to Measure For Exterior Shutters

Measuring for wood or composite exterior shutters requires a little time and a few tools, including a steel tape measure, ladder, pencil and paper. Expect to spend about 5-10 minutes per window to obtain proper measurements.

How to measure for exterior shutters to be installed on house windows.

Functional Exterior Shutters

Solid exterior shutters, in conjunction with quality outdoor hardware, can be installed to swing open and closed. Measurements of each window for functional shutters need to be made with great precision to ensure a smooth installation. Multiple openings that appear to be the same size can often be very different.

Stationary Outdoor Shutters

Wood or composite shutters that will be installed in a permanent position can afford to be approximate in relation to the window size. This type of stationary installation can be accomplished with screws or bolts. Decorative panels may still look functional if they are installed with authentic shutter hardware.

Measure Windows for Exterior Shutters

Time needed: 10 minutes.

Steps to measure for exterior shutters:

  1. Inspect the Windows

    Observe and make note of any obstructions on either side of the window which may prevent proper installation of exterior shutters (downspouts, building corners, roof lines, flagpole mounts, etc.). Pay particular attention to the space between neighboring windows to establish adequate proportions and adjacent shutters will not collide. Also, assess the area in front of the window to verify there are no obstructions that will impede the panels from rotating (trees, shrubs, fence posts, etc.). Take this opportunity to check the window frame for wood rot that can be replaced in advance of installation.

  2. Measure Exterior Shutter Depth

    It is preferable for functional outdoor shutters to fit entirely within the window opening. Measure from the back of the side jamb to the front of the window casing. Premium wood shutters require a void of 1.5 inches, while composite shutters need 1.25 inches and Pine shutters 1 inch.

    Windows without adequate depth to accommodate functional shutters that nest inside the opening will need to install in front of the casing with “new construction shutter hinges”.

  3. Measure Window Width

    Measure from the inside left of the window opening to the inside right. Survey three places and record the narrowest dimension, then deduct ¼ – ½ inch for adequate margin when closing. Divide this calculation by two (2) for the individual exterior shutter width. Windows measuring less than 32 inches wide may use a single shutter that opens to one side.

    For shallow window openings, measure from the outside left of the window casing, or trim, to the outside right. Divide this measurement by two for the individual shutter width.

  4. Measure Window Height

    Measure from the inside top of the window opening to the inside bottom. Check in three places and record the narrowest amount, then deduct ¼ – ½ inch to maintain clearance when closing. This is the panel height.

    If the window is shallow, measure from the outside top of the window casing to the top of the sill, or bottom of the casing if there is not sill.

  5. Establish Divider Rail Location

    A divider rail is a horizontal bar, much like the top rail, that creates top and bottom louver areas within the exterior shutter. A divider rail is optional on all louvered shutters and paneled shutters under 70 inches, and is required on combination shutters and all other panels in excess of 70 inches. A divider rail can be centered by default or positioned at a custom location. If a custom location is desired, provide the measurement from the bottom of the shutter to the identified center of the divider rail. For two divider rails, note the location of each from the bottom of the shutter to the center of each.

    If there is an existing horizontal division (created by a transom, mullion, or window sash) in the window, it is often preferable to align the shutter divider rail at the same height.

    The actual placement of the divider rail will be close to the location requested. The number of louvers, shutter height and rail sizes determine the final placement.

    A third center batten is required on board and batten shutters over 55 inches in height. The addition of a optional fourth batten or a z-pattern batten may be selected.

    Large functional exterior shutters may require more support than two hinges can provide. A divider rail or center batten is essential to affix a third strap hinge.

How to measure windows for exterior shutters with width and height.

Composite Shutters

Composite shutters can be installed with functional hardware, but have a flat non-decorative back, which will be visible when the shutters are rotated over the window in a closed position. All styles of composite exterior shutters are heavier than their wood counterparts. Composite shutters may need additional hinges to support the additional weight.

Exterior windows have many variables (siding material, casing width, etc.) which results in a modified approach to each application. The instructions furnished here need to be adapted for your house configuration.

Wood Shutters

Premium wood shutters and economy pine shutters can both be installed to be functional or stationary. Louvered shutters have the same appearance front and back, except the louvers up on one side and down on the other. Board & batten and raised panel shutters have little detail on the back are are intended to be viewed from the front most of the time.

More about Stationary Exterior Shutters

Decorative shutters installed for only aesthetic purposes are not restricted by exact fit requirement. The goal for decorative shutters is to make them symmetrical to the size of the window.

The preferred appearance for stationary shutters is to simulate those that are functional, aligning with the window opening. Follow the instructions above on how to measure for exterior shutters to complete this outcome.

Some windows are wider than what could logically contain two shutter panels. Follow the steps below to guide you through how to measure wide windows for exterior shutters.

Exterior Shutters for Extremely Wide Windows

Shutter Width of Wide Windows

Windows wider than 64 inches will need to use shutters that are narrower than optimal. Use the widest possible to accent the home. It is advisable to select a width size divisible into the window width. Shutter size should be between 25-50% of the window width in order to remain aesthetically pleasing.

Never install house shutters that are wider than the window.

Outdoor Shutter Hardware

Operable exterior shutter hinges are necessary to give wood or composite shutters the ability to swing open and closed. Is is best to evaluate the best hinge for the installation at the same time window measurements are taken. Survey the available mounting surface and establish the necessary offset.

Shutter dogs restrain outdoor window shutters in an open position to either side of the opening. Tiebacks work in a variety of ways to lock and release the panels, with many in ornate designs to give the house added interest.

Bahama Shutters

Tropical bahama shutters are designed to cover an entire window opening with a single panel up to 85 inches. Record measurements of the entire window width and height as specified above. Exceptionally wide windows can be covered in multiple Bahama shutter panels.

How to Measure for Arch Top Shutters

Some shutter styles can be made with a curved top designed to match the contour of a round top window. Arch top exterior shutters require a drop ratio and springline measurement.


Measure for Vinyl Shutters

There is a slightly different process to measure for vinyl shutters. Polypropylene shutters are sold in fixed widths at various intervals. They also have a different installation method to consider.

Shutter Measuring Tips:

  • Use a steel tape measure. Don’t attempt to measure with a yard stick or ruler.
  • Employ an assistant to help with larger windows.
  • Don’t assume similar windows are the exact same size. Check all windows to assure accuracy.
  • A sturdy ladder is essential for safety when measuring tall or elevated windows.