How to Measure for Hurricane Shutters Accurately

Last updated: 2025-04-10

Getting accurate measurements is the foundation of a successful hurricane shutter installation. A quarter-inch mistake can mean shutters that won't fit, gaps that compromise protection, or costly remeasurement and reordering. This guide walks you through the exact process we use on Florida properties before ordering panels or roll-downs.

Why Accurate Measurements Matter for Hurricane Shutters

Precise measurements determine whether your hurricane shutters will seal your openings completely. Storm protection depends on tight coverage, and poor measurements lead to either wasted material or inadequate protection when winds push against loose panels.

Incorrect measurements also drive up your total hurricane shutters cost. Remeasuring and reordering adds weeks to your project timeline and often triggers restocking fees or rush charges. Contractors see this constantly: a single missed dimension can cascade into expensive callbacks.

And here's the thing—when you order custom panels or motorized roll-downs, manufacturers build to spec. There's no universal size. A 36-inch opening isn't the same across two homes. Getting it right the first time is the only efficient path forward.

Tools You'll Need

You only need four items to measure accurately:

1. Steel measuring tape (25-foot minimum). Cloth tapes stretch and introduce error. A metal hook that sits flat against the frame corner is essential.
2. Notebook and pencil. Write measurements on-site immediately. Phone photos of the rough numbers work as backup.
3. Level (optional but valuable). Wind-driven rain leaks past frame angles that are out of plumb. A 2-foot bubble level on each side tells you if the opening is square.
4. Flashlight or phone light. Interior frame angles are shadowed. You need to see the exact corner where frame meets sill or jamb.

Don't rely on estimates, previous quotes, or prior contractor notes. Measure every opening fresh.

Measuring Width: The Critical Dimension

Width is the most common measurement error because most people measure the glass instead of the opening.

1. Measure the inside face of the left jamb (vertical frame member) to the inside face of the right jamb. Don't measure glass-to-glass. The frame is what shutters attach to.
2. Take the measurement at three points: top, middle, and bottom of the opening. Write all three numbers down.
3. Use the smallest of the three widths as your order dimension. If the opening narrows toward the bottom, you must accommodate that narrowest point.
4. If the three measurements vary by more than half an inch, the opening may be out of square. Note this on your worksheet and mention it to your installer.

Step-by-step width measurement:

1. Position tape at inside-left jamb corner
2. Pull tape horizontal across to inside-right jamb
3. Record measurement at top of frame
4. Repeat at middle height of opening
5. Repeat at bottom of frame
6. Use the smallest recorded width as your order specification

Measuring Height: Accounting for Sills and Thresholds

Height measurement depends on whether you're covering a window or a door.

For windows:

1. Measure from the inside face of the sill (the horizontal piece at the bottom) to the inside face of the header (horizontal piece at the top).
2. Measure at three points: left side, center, and right side of the frame.
3. Use the smallest height as your order dimension, just as you did for width.
4. Check whether the sill slopes outward for drainage. Sloped sills are normal and don't affect measurement, but note the slope if it's extreme.

For doors:

1. Measure from the floor or door threshold (the raised piece at the bottom) to the header at the top.
2. For French doors or sliding glass doors, measure the glass opening only, not the frame rails between panels.
3. If the threshold is recessed, measure from the lowest point where the shutter will contact the frame.

Common mistake: Measuring from the wall surface instead of the actual frame opening. The frame is set back from exterior wall material (brick, vinyl, stucco). Measure the frame itself.

Recording Measurements: The Worksheet Template

Create a simple table as you measure. Here's the format that works:

Write down the opening name (room, location), all six measurements, and your final usable dimension in the Notes column. Take a photo of this worksheet on your phone. When you call for a quote or submit an order, you've got a permanent record.

Measuring Curved or Arched Openings

Homes with curved window tops or arched transoms need special handling. You can't just apply a single rectangular measurement to an arch.

For arched windows, measure the standard rectangular opening (the widest, flattest part), then note the curve separately. Most installers photograph the arch or take a cardboard template to ensure the shutter accommodates the shape during installation. Don't try to calculate the curve mathematically—let the professional see it.

Hurricane shutters for arches typically require custom fabrication, which gets reflected in your total hurricane shutters cost. A standard rectangular panel costs less than a custom-arched panel, so clarify this before ordering.

Accounting for Frame Protrusions and Trim

Many windows sit in frames that protrude slightly from the wall surface. This matters for certain shutter types.

1. Measure the depth of the frame (how far it sticks out from the wall plane) with your tape held perpendicular.
2. Note any exterior trim, casing, or flashing around the frame edge. These protrusions affect how mount brackets sit.
3. For roll-down shutters mounted above windows, measure the horizontal space above the frame where the housing will sit. Confirm there's no soffit, awning, or siding overhang blocking installation.

Most installers account for these details during the site visit, but flagging them in your measurements avoids surprises.

Checking Square and Level

An opening that's out of square or out of plumb is still measurable, but the installer needs to know.

1. Place your level vertically on the left jamb. Record if it's plumb or leans.
2. Repeat on the right jamb.
3. Place the level horizontally on the sill. Record if it's level or slopes.

If any jamb or sill is more than a quarter-inch off plumb or level, note it prominently. This won't stop the order, but it alerts your installer to possible shimming or bracket adjustment during installation.

Taking Photos: The Backup System

After recording measurements, take a clear photo of:

1. The full opening (wide shot from inside looking out).
2. The measurement worksheet with numbers visible.
3. Any unusual features (heavy trim, electrical outlets above the opening, nearby downspouts, etc.).

Photos become valuable reference points if your installer has questions before the truck arrives. They also protect you if there's a dispute about measurement accuracy later.

Frequently Asked Questions

Do I need to hire a professional to measure for hurricane shutters?

No, many homeowners measure accurately themselves using the method described here. But if your openings are unusual, out of square by more than half an inch, or if you're ordering high-end roll-downs where installation is complex, a professional site survey is worth the cost. We often provide free or low-cost measurement consultations.

What if my opening is not a standard rectangle?

Trapezoid, arch, or L-shaped openings require a site visit or detailed photo documentation so the manufacturer or installer can design the right solution. Standard rectangular measurements alone won't work for non-standard shapes.

Should I add extra inches for ventilation or adjustments?

No. Order exact measurements for the frame opening. Adding buffer inches creates gaps that compromise storm protection. Installers know how to seal and adjust during installation without padding the order.

Can I use exterior measurements instead of interior frame measurements?

Not reliably. Interior frame measurements are the standard because that's where shutters attach. Exterior measurements vary based on wall thickness, trim, and siding. Always measure inside.

What if my measurements vary by half an inch between different points?

Use the smallest measurement in each direction. A width that measures 36" at the top and 35.5" at the bottom means order 35.5". The shutter must fit the narrowest point or it won't close properly.

---

Ready to get an accurate quote for your home? Visit our services page to request a professional measurement consultation, or review pricing information for different shutter types. Accurate measurements save time, money, and protect your family when the storm hits.