How to Measure and Calculate Window Film

How to Measure and Calculate Window Film for Ordering

Step-by-Step Measurement Guide

Step 1: Measure Each Window Pane

Use a tape measure to determine the width and height of the glass — measure from edge to edge of the glass only (inside the window frame, not including the frame itself). Measure in multiple places (top, middle, bottom for width; left, middle, right for height) to account for any irregularities. Record the smallest measurement for both width and height.

Step 2: Add Trim Allowance

Add 1/4 inch (6mm) to each side of both measurements. This extra allowance lets you trim the film to a perfect fit after application. So if your glass measures 36" wide × 60" tall, you would order film cut to 36.5" × 60.5".

Step 3: Choose Your Roll Width

Most Solar Gard films we sell are offered in 36, 48, 60 and 72 inch widths, in 50-foot and 100-foot lengths. Sizes vary by product — for example, PureVue 70 is offered in 60" and 72" widths, GraffitiGard 7 Mil in 48", 60" and 72", Ecolux 70 in 48" and 58" × 100 ft, and WingSafe bird-protection film in 95-foot rolls. Always confirm available sizes on the product page. Choose the roll width that is closest to (but not smaller than) your widest window measurement. For windows wider than 72 inches, you will need to install the film in panels.

Step 4: Calculate How Many Linear Feet You Need

For each window, you need a piece of film equal to the window height (plus trim allowance). Add up all window heights to get your total linear feet needed from the roll.

Step 5: Account for Multiple Windows

If you have multiple windows of the same width, you can cut them all from the same roll. Total linear feet = sum of all window heights (with trim allowance) for windows that fit within your chosen roll width.

Step 6: Add a Waste Allowance and Choose a Roll Length

Add about 10% to your total for trimming, mistakes and future repairs, then choose the roll length (50 ft or 100 ft, where offered) that covers it. Example: ten windows, each 34" × 54", fit a 36" roll. Ten heights × 54.5" (with trim) = 545" ≈ 45.4 ft; plus 10% ≈ 50 ft. A 36" × 50 ft roll is just enough; a 36" × 100 ft roll leaves spare film for repairs.

Before you order: check that your film is compatible with your glass (especially double-pane, Low-E, tinted or laminated glass) in our film-to-glass compatibility guide, and review the installation guide.

Roll Size Guide

Not every width and length is available for every film. Coverage is the gross roll area before trimming.

Special Considerations

Frequently Asked Questions

Should I order a 50 ft or a 100 ft roll?

Add up the film length you need (window heights plus trim, plus about 10%). If it is under 50 ft and the film is offered in 50 ft, a 50 ft roll may be enough; a 100 ft roll covers larger projects and leaves film for repairs. Check each product page for the lengths offered.

What if my window is wider than 72 inches?

Install the film in vertical panels with a small seam, or rotate the film where the window height is within the roll width. Contact us if you are unsure.

Does the type of film change how much I need?

No — the amount depends on your glass size. Film type affects price and the widths available.