1. Glass Size (Actual)

What it is: The overall size of the glass pane itself. This is the glass only — no frame included in this measurement.

Example: 22" x 36"

This is the size listed on all DIY Door Store products and the size you order.

2. Outside Frame Dimensions (O.D.)

What it is: The overall size of the frame that surrounds the glass. This includes the frame lip that sits against the door face on all sides.

Example: 24" x 38" (± 1/4" on the last dimension)

Relationship: Approximately 2" larger than glass size in each direction. If you measure the outside frame, subtract 2" from each dimension to get the glass size you need (± 1/4").

3. Visible Glass (Approximate)

What it is: The area of glass that is visible when looking at the door from the front. This is smaller than the actual glass size because the frame lip covers approximately 5/8" of glass on each side.

Example: ~20-3/4" x 34-3/4" (for a 22" x 36" glass insert)

Do not use this measurement to order. If you measure only what you can see, your number will be too small and you may order the wrong size.

4. Door Cutout (Opening)

What it is: The rectangular opening cut into the door slab to accept the insert. The insert fits into this opening from the front of the door.

Example: 23" x 37"

Relationship: Exactly 1" larger than the glass size in each direction. This is the most reliable measurement to take because it is a fixed, machined dimension.

💡 Always measure the door cutout (opening), not the insert or the glass, when preparing your door.

Subtract 1" from the cutout width and 1" from the cutout height. That is your glass size. Example: 23" x 37" cutout → order a 22" x 36" insert.

Method A: Measure the Door Cutout (Most Accurate)

Step 1: Remove the existing glass insert from the door (unscrew the interior frame, slide the insert out).

Step 2: Measure the rectangular opening in the door slab — width first, then height.

Step 3: Subtract 1" from each dimension. That is your glass size.

Step 4: Confirm your door thickness is 1-3/4" (standard exterior). If it is 1-3/8", you have an interior door — see our interior door glass kits.

Example: 23" x 37" cutout − 1" each = 22" x 36" glass size.

Method B: Measure the Outside Frame (Without Removing Insert)

Step 1: Measure the plastic frame from outside edge to outside edge — width first, then height. Include the full frame lip on both sides.

Step 2: Subtract 2" from each dimension (± 1/4"). That is your glass size.

Example: 24" x 38" frame − 2" each = 22" x 36" glass size.

⚠ Do NOT measure only the visible glass

The glass you can see through the frame is smaller than the actual glass pane because the frame lip covers approximately 5/8" on each side. If you measure only what you can see, you will get a number like 20-3/4" x 34-3/4" for what is actually a 22" x 36" insert. This will lead you to order the wrong size. Always use the cutout or outside frame method instead.

Not sure which measurement you have? Call (888) 998-3667 or email us with your numbers and we will tell you which glass size to order. You can also text or email a photo of your door with a tape measure — we can usually identify the size from a photo.

My measurement is close to a standard size but not exact. Is that normal?

Yes. Door cutouts are machined to standard dimensions, but minor variation (± 1/4") is normal. If your cutout measures 22-3/4" x 36-3/4", that is a standard 23" x 37" cutout — order a 22" x 36" insert.

Does the glass type (clear, privacy, decorative) affect the size?

No. Glass type does not change the physical dimensions. A 22" x 36" clear glass insert, a 22" x 36" rain glass insert, and a 22" x 36" decorative insert all fit the same 23" x 37" cutout.

Do I need to remove the insert to measure?

Not necessarily. Method B (measuring the outside frame) works without removing the insert. However, measuring the door cutout directly (Method A) is more accurate because it eliminates the ± 1/4" frame tolerance. If your glass is broken and already removed, measuring the cutout is the easiest approach.

My door has a 20" wide glass but most listings show 22" wide. Did I measure wrong?

Probably not. 20" wide inserts are the standard "narrow" size, typically found on doors that are 30" wide or narrower. 22" wide inserts are the standard size for 32" to 36" wide doors. Both are industry standard.

Will a glass insert from one brand fit a door from a different brand?

Yes, in most cases. The industry uses standardized cutout dimensions. A 22" x 36" glass insert fits the 23" x 37" cutout in a Therma-Tru, Masonite, JELD-WEN, Pease, Taylor, Stanley, or Castlegate door.

Does glass thickness matter when ordering?

Glass thickness (typically 1/2" or 1") affects which frame profile you need, but does not change the width and height. Our Glass & Frame kits include the correct frame for the glass thickness. If ordering Frame ONLY, check the listing to confirm it matches your glass thickness.

Still Not Sure? We Will Help You Measure.

Call (888) 998-3667 or email [email protected] with a photo of your door and a tape measure held against the frame. Our team can identify your size from a photo in most cases. We would rather spend two minutes verifying your measurements than process a return.

DIY Door Store is a division of Taylor Door Company, a Michigan-based door manufacturer with over 35 years of experience in door glass and frame systems.