Installing a storm door increases security and brings natural light into a dark entryway. But before you head to the hardware store, you need to know exactly how to measure for a storm door. If you get the numbers wrong, you will be stuck with a heavy door that simply won’t fit.
This guide walks you through getting accurate storm door measurements so you can install it right the first time.
Key Takeaways
- Check for obstructions: Inspect the door frame for handles, doorbell buttons, and porch pillars that might block the installation or swing path.
- Measure the height: Measure from the threshold to the underside of the top exterior trim on the left, right, and center; use the shortest measurement.
- Measure the width: Measure the width between the interior face of the exterior trim at the top, middle, and bottom; use the narrowest width.
- Verify mounting depth: Ensure your exterior trim (brickmould) has at least 1 inch of flat surface area to mount the storm door frame.
How to Measure for a Storm Door
The first step is checking for obstructions. Pillars, mailboxes, and foliage can all stop a door from swinging open fully. Even the thickness of your house numbers or a large doorbell can get in the way of the frame installation.
You also need to decide the “handing” of the door, which is just a fancy way of saying which side the hinges go on. Typically, you want the storm door to hinge on the same side as your main entry door. However, if an obstruction blocks that side, you may need to switch it.
Take a close look at your main entry door handle. If you have a large decorative handle set, it might hit the glass or screen of the storm door. You may need to extend the storm door frame out or choose a handle with a lower profile.
Here is an at-a-glance list of common obstructions to watch out for:
- Door handles (measure how far they stick out).
- Pillars or columns.
- Porch railings.
- Mailboxes.
- Plants or bushes.
- House numbers.
- Doorbells.
- Outdoor light fixtures.
One To Watch
Always choose the hinge side with the fewest obstacles to ensure the door can swing open fully.
What You’ll Need
- Tape measure.
- Pencil.
- Notepad or paper.
1. Measure the Height
Measure the height of the door opening from the top of the metal threshold (the bottom plate you step over) to the underside of the header (the top piece of exterior trim).
Do this three times: once on the left side, once in the middle, and once on the right.
Ideally, these numbers will be identical. If they aren’t, use the shortest measurement as your guide. Most standard storm doors fit openings between 80 and 81 inches high. Write this number down immediately.
2. Measure the Width
Next, measure the width of the opening. Place your tape measure against the inside face of the exterior trim (often called the brickmould) on the left and measure to the inside face of the trim on the right.
Measure at the top, middle, and bottom of the door frame. Just like the height, you must use the narrowest width measurement as your guide.
3. Check the Mounting Surface Depth
Most storm doors install directly onto the face of your exterior trim (brickmould). For a secure installation, you need enough flat surface area to attach the mounting rails.
Measure the width of the face of your trim. Most standard doors require at least 1 inch of flat surface. If your trim is decorative, curved, or too narrow, you might need to install a mounting strip or shims to create a flat surface.
4. Estimate the Size
Door dimensions are always written as Width x Height. Take your narrowest width and your shortest height to determine your size.
For example, if your width is 36 inches and your height is 80 inches, you need a 36×80 storm door. If your measurements fall slightly outside standard ranges, don’t worry; most installation kits come with adjustment rails (Z-bars) that can handle small variances.
Top Tip
Measure twice, buy once. Writing down the wrong number is a hassle that leads to heavy returns and wasted afternoons.
Standard Storm Door Size Chart
Manufacturers love standard sizes because they are cheaper to mass-produce. If your home was built in the last 30 to 40 years, you are likely in luck.
Your door opening will probably fall between 30 and 36 inches wide and 80 to 81 inches high. If your measurements align with the chart below, you can pick up a door off the shelf at most home improvement stores. If you need a custom size, the price tag usually jumps significantly.
The chart below lists standard door fit ranges from major brands like Andersen, EMCO, and Larson.
| Standard Size Width Range | 30 inches | 32 inches | 34 inches | 36 inches | Standard Door Height Range |
| Andersen 3000 and 4000 storm door (Easy Install System) | 29.88 to 30.38 inches | 31.88 to 32.38 inches | 33.88 to 34.38 inches | 35.88 to 36.38 inches | 80 to 80.88 inches |
| Andersen 3000 TruEase, 2500, and 200 series (excluding Forever®) | 29.75 to 30.38 inches | 31.75 to 32.38 inches | 33.75 to 34.38 inches | 35.75 to 36.38 inches | 80 to 80.88 inches |
| Larson (No Shim Required) | 29.88 to 30 inches | 31.88 to 32 inches | 33.88 to 34 inches | 35.88 to 36 inches | 80 to 81 inches |
| Larson (Shim Required) | 30.88 to 31.17 inches | 32.17 to 32.88 inches | 34.17 to 34.88 inches | 36.17 to 36.88 inches | 74.5 to 75.5 inches |
Note that a “36-inch door” isn’t exactly 36 inches wide; it is designed to fit an opening of roughly 36 inches. The adjustment rails fill the gaps.
Custom Size Storm Doors
Sometimes standard just doesn’t work. If you live in an older historic home with very tall doors, or a mobile home with a narrow 30-inch or 32-inch entry, you might need a custom order.
Most major hardware stores can order custom sizes from manufacturers like Larson or Andersen. You will need to provide your exact measurements to the associate. Be prepared for a lead time of several weeks and a higher price point.
FAQs
What Is the Difference Between a Storm Door and a Screen Door?
People often use the terms interchangeably, but they are different. A screen door is a lightweight frame with mesh, designed solely to keep bugs out and let air in. A storm door is heavier, features glass panels for weather protection, and often has a retractable screen option. Storm doors seal your home against wind and rain, while screen doors do not.
Should You Paint a Storm Door?
Yes, you can paint a storm door if the factory finish doesn’t match your style. However, you must use a high-quality paint designed for metal or vinyl exteriors, such as Zinsser Exterior White. Keep in mind that painting a new door might void the manufacturer’s warranty, so check the fine print first.
Should a Storm Door Match Your Trim or Door Color?
This is entirely up to your aesthetic preference. Many homeowners choose a storm door that matches the exterior trim (often white) to make the door frame “disappear.” Others match the front door color for a seamless look. There are no hard rules here, so go with what looks best on your house.
How Much More Does a Custom Size Storm Door Cost?
Custom-sized storm doors typically cost significantly more than standard stock models. While a standard door might run between $150 and $400, a custom order can easily range from $800 to over $1,500, depending on the glass style and finish.
How Do I Know Which Way My Storm Door Should Swing?
Face your door from the outside. Ideally, your storm door should hinge on the same side as your main entry door so they both open together. This is called “hinging left” or “hinging right” (as viewed from the outside). If there are obstructions like a light fixture or mailbox on that side, you may have to hinge it on the opposite side.
Brewing Up a Storm
Getting the measurements right is the most critical part of this project. Once you have your height, width, and depth confirmed, buying the door is the fun part.
Whether you grab a standard model off the shelf or order a custom piece for a unique entryway, accurate numbers ensure a smooth installation. Take your time with the tape measure now, and you’ll be enjoying that fresh breeze in no time.
