Why a 35" Window Often Uses a 34.5" Blind
When a blind is mounted inside the window frame (an “inside mount”), the finished blind is made about ½ inch narrower than the opening. That small deduction gives the headrail and slats room to tilt, raise, and lower without scraping the frame. So a 35-inch opening is paired with a 34.5-inch blind, a 58-inch opening with a 57.5-inch blind, and so on.
This is why builder blind widths so often end in “.5” — they are the standard openings minus the inside-mount clearance. If you mount outside the frame instead, the rule flips: you order the blind wider than the opening so it overlaps and blocks light. One exception: roller shades are ordered at the exact window-opening size with no deduction.
Common Builder Window Openings
Use this chart to convert a measured inside-mount opening to the blind width we stock. Each blind width links to every standard length available at that size.
| Window opening (inside mount) | Typical blind width | Commonly used for |
|---|---|---|
| 24" | 23.5" | Door glass, sidelights, and narrow utility windows (see door blinds below) |
| 32" | 31.5" | Standard bedroom and living-room windows |
| 34" | 33.5" | Common builder-spec single-hung |
| 35" | 34.5" | Top-selling single-hung width |
| 39" | 38.5" | Larger bedroom and living-room windows |
| 43" | 42.5" | Wide bedroom and great-room windows |
| 47" | 46.5" | Double-hung and small picture windows |
| 58" | 57.5" | Wide casement and picture windows |
| 59" | 58.5" | Wide-format picture windows |
| 71" | 70.5" | Large picture and sliding windows |
| 72" | 71.5" | Outside-mount door and patio coverage |
Measurements are typical inside-mount pairings. Always confirm your exact opening and mount type before ordering.
Narrow blinds for doors (22.5"–25" wide)
Blinds in the 22.5"–25" width range are most often used on doors — back doors, French doors, and half- or full-glass entry doors — rather than standard windows. Because the blind mounts on the door surface over the glass, these are ordered as an outside mount in 2" faux wood, with standard drops of 64", 72", and 84" to cover the full door-glass panel. Browse 23.5" door blinds or 25" door blinds.
The narrow glass panels on either side of a front door are called sidelights, and they use even narrower blinds — typically 8"-wide 2" faux wood with standard drops of 64", 72", and 84". They can be ordered inside or outside mount depending on how the sidelight frame is configured. Browse 8" sidelight blinds.
Inside Mount vs. Outside Mount
Inside mount
The blind sits inside the window frame for a clean, built-in look. Report the exact opening width and the factory deducts about ½" for clearance. Requires enough frame depth for the headrail. Best for windows with square openings and adequate depth.
Outside mount
The blind mounts on the wall or trim above the window and overlaps the opening, usually by 1.5–2" per side. Order the blind wider and taller than the opening. Best for shallow frames, out-of-square openings, or when you want maximum light blockage and privacy.
How Builders Measure Windows
- Measure the width at the top, middle, and bottom of the opening.
- Measure the height at the left, center, and right of the opening.
- For an inside mount, use the narrowest width and the longest height, then let the factory apply the standard deduction.
- For an outside mount, add your desired overlap (typically 1.5–2" per side) to the opening size.
- Round to the nearest 1/8" and record measurements to the exact fraction.
Want the step-by-step with photos? See our full measuring & installation guide.
Most Common Blind Sizes by Room
| Room | Typical width | Typical length | Recommended product |
|---|---|---|---|
| Bedroom | 31.5" – 35" | 60" – 72" | 2" faux wood or vinyl mini |
| Living room | 34.5" – 58" | 60" – 72" | 2" faux wood or wood |
| Dining room | 34.5" – 46.5" | 60" | 2" faux wood |
| Tall / two-story window | 34.5" – 58" | 84" – 96" | 2" faux wood (96" length stocked) |
| Patio / sliding glass door | 70.5" – 100"+ | 84" | 3.5" PVC vertical blinds |
Production Home Window Size Ranges
While exact window dimensions vary by floorplan, large production builders tend to cluster window openings into a small set of standardized width ranges that correspond to common blind sizes. They reuse the same window modules across floorplans and subdivisions because it lowers cost, speeds up framing and installation, and keeps them tied to standard supplier sizes. That is why the same handful of blind widths show up again and again in new-construction homes.
| Window type | Typical opening width | Typical blind width | Where you'll see it |
|---|---|---|---|
| Small | 24" – 36" | 23.5" – 35" | Bathrooms, secondary bedrooms, utility windows |
| Standard | 36" – 60" | 35" – 58" | Bedrooms, kitchens, single- and double-hung windows |
| Wide | 60" – 72"+ | 58" – 71.5" | Living rooms, great rooms, picture windows |
| Patio / sliding door | 72" – 100"+ | 3.5" vertical blinds | Open-concept living areas, patios |
These are industry-standard production-home ranges, not the proprietary specification of any one builder. Always confirm your own openings before ordering.
Blinds by Home Builder
Just closed on a new build? Each major builder tends toward different window patterns. These guides cover the sizes, products, and measuring tips for the most common production builders:
Standard Lengths (Drops)
Builder blinds are stocked in a handful of standard drops to keep turnarounds fast: 60" for most standard windows, 72" for taller windows, and 84" and 96" for two-story and patio-height openings. The 96" length is a common builder drop that many online retailers do not carry — we stock it on faux wood and across the builder catalog.
Frequently Asked Questions
What size blind do I need for a 35 inch window?
For an inside mount inside a 35-inch-wide opening, you typically order a 34.5-inch blind. Finished inside-mount blinds run about a half inch narrower than the opening so the headrail and slats clear the window frame. For an outside mount, you would instead order a blind a few inches wider than the opening to overlap it.
Why is my blind smaller than my window?
Inside-mount blinds are intentionally cut about ½ inch narrower than the window opening. That clearance lets the slats tilt and the blind raise and lower without rubbing the frame. It is normal and expected — a 35-inch opening using a 34.5-inch blind is the standard builder pairing.
Should blinds be narrower than the window opening?
For an inside (recess) mount, yes — about ½ inch narrower so the blind fits cleanly inside the frame. For an outside (surface) mount, the opposite is true: the blind should be wider and taller than the opening, usually overlapping each side by 1.5–2 inches to block light gaps. Roller shades are the exception and are ordered at the exact opening size.
What are the standard builder blind sizes?
The most common builder blind widths are 23.5", 31.5", 33.5", 34.5", 38.5", 42.5", 46.5", 57.5", 58.5", and 70.5", paired with standard drops of 60", 72", 84", and 96". 34.5" wide is the single best-selling builder width, and 96" length is a tall-window drop many online retailers do not stock.
What is the most common blind size in new construction?
34.5" wide is the most common single blind size in new-construction homes because it fits the standard 35" single-hung window opening after the ½" inside-mount deduction. Most homes use a mix of widths from about 34.5" to 70.5" depending on the room and window, with 60" and 72" being the most common lengths.
Do builders include blinds in new homes?
It varies by builder and price tier. Some builders include basic blinds (often faux wood or vinyl mini) as a standard or upgrade option at closing, while others leave windows uncovered so the buyer chooses their own. Because builder window sizes are standardized, it is easy to order matching blinds afterward — that is exactly what our stocked builder widths are for.
How do I measure a window for builder blinds?
Measure the exact window-opening width at the top, middle, and bottom, and the height at the left, center, and right. For an inside mount, report the smallest width and the longest height and let the factory apply the standard deduction. For an outside mount, decide how far the blind should overlap the opening on each side and add that to your measurements.
What size blinds do I need for a sliding glass door?
Standard sliding glass doors are roughly 60" to 96" wide and about 80" tall. 3.5" PVC vertical blinds are the usual builder and multifamily choice for this opening, commonly ordered around 70.5"–100"+ wide by 84" long depending on the door.
What size blinds do I need for a door window?
Blinds for doors are narrow — usually about 22.5 to 25 inches wide — to match the door-glass panel. Because they mount on the door surface over the glass, door blinds are ordered as an outside mount in 2" faux wood, with standard drops of 64", 72", and 84" so they cover the full glass.
Ready to order the right size?
Browse stocked widths and shop the most popular new-home blinds, or have us measure and install for you across Dallas–Fort Worth.
Property manager or handling apartment turns? See our commercial & multifamily page.