Why Use a Window Blinds & Treatment Calculator?
Even a 1/8-inch measuring error can cause inside mount blinds to bind against the window casing or leave unsightly light gaps:
- Factory Operating Clearance: Automatically adjust ordering dimensions based on standard manufacturer 1/2-inch width deductions for inside mounts.
- Outside Mount Light Blocking: Add optimal 2-inch to 3-inch wall overlap per side to maximize privacy and room darkening.
- Minimum Depth Verification: Verify window frame casing depth requirements for flush headrail installations.
- Slat Count & Square Footage: Calculate precise material requirements across 1”, 2”, or 2.5” horizontal slat styles.
Window Blinds Calculation Formulas
\[\text{Inside Mount Order Width} = \text{Exact Window Opening Width} - 0.50''\] \[\text{Inside Mount Order Height} = \text{Exact Window Opening Height}\] \[\text{Outside Mount Order Width} = \text{Exact Window Opening Width} + (2 \times \text{Outside Overlap})\] \[\text{Outside Mount Order Height} = \text{Exact Window Opening Height} + (2 \times \text{Outside Overlap})\] \[\text{Blind Area (sq ft)} = \frac{\text{Order Width (in)} \times \text{Order Height (in)}}{144}\] \[\text{Estimated Slat Count} = \left\lceil \frac{\text{Order Height (in)}}{\text{Slat Width (in)}} \right\rceil\] \[\text{Total Custom Blind Cost} = \text{Blind Area (sq ft)} \times \text{Price per Sq Ft}\]Real-World Window Blinds & Treatments Comparison Table
The table below details ordering dimensions, slat counts, square footage, and custom blind material costs across common window sizes using standard 2-inch slats ($12/sq ft rate).
| Window Opening Size | Mount Style | Slat Size | Ordered Width | Ordered Height | Slat Count | Total Area (sq ft) | Estimated Cost |
|---|---|---|---|---|---|---|---|
| 24” × 36” Small Window | Inside Mount | 2.0” Slat | 23.50 in | 36.0 in | 18 Slats | 5.88 sq ft | $70.50 |
| 36” × 60” Standard Window | Inside Mount | 2.0” Slat | 35.50 in | 60.0 in | 30 Slats | 14.79 sq ft | $177.50 |
| 36” × 60” Standard Window | Outside Mount (2” overlap) | 2.0” Slat | 40.00 in | 64.0 in | 32 Slats | 17.78 sq ft | $213.33 |
| 48” × 72” Large Picture | Inside Mount | 2.5” Slat | 47.50 in | 72.0 in | 29 Slats | 23.75 sq ft | $285.00 |
| 72” × 60” Triple Window | Outside Mount (3” overlap) | 2.0” Slat | 78.00 in | 66.0 in | 33 Slats | 35.75 sq ft | $429.00 |
Step-by-Step Guide: How to Measure Windows for Custom Blinds
- Check Frame Depth: Use a tape measure to verify that your window casing has at least 2 to 2.5 inches of clear un-obstructed depth.
- Measure Width for Inside Mount: Measure window opening width at top, middle, and bottom. Take the smallest of the 3 numbers.
- Measure Height for Inside Mount: Measure height at left, center, and right. Take the longest of the 3 numbers.
- Determine Outside Mount Coverage: For windows with shallow depth, measure outer trim width and add 2 inches per side.
- Select Headrail & Valance Options: Confirm valance clip clearance and control wand orientation before placing custom order.
Frequently Asked Questions
What is the difference between inside mount and outside mount blinds?
Inside mount blinds fit inside the window frame recess for a clean, built-in architectural look. Outside mount blinds mount on the wall or trim surrounding the window frame, which is ideal when window depth is shallow or to block light leaks completely.
Should I deduct 1/2 inch myself for inside mount blinds?
No. Always order exact window opening measurements for inside mount blinds. Blind manufacturers make a standard 3/8” to 1/2” factory deduction from the ordered width so the blind raises and lowers without binding against the window frame.
How much depth is needed for inside mount 2-inch faux wood blinds?
A minimum casing depth of 2 inches is required for standard inside mounting, and 2.75 to 3 inches is required for a completely flush inside mount where the headrail does not project past the wall surface.
How do I measure outside mount window blinds?
Measure the width of the window opening or outer trim molding and add 2 to 3 inches of wall overlap per side (4 to 6 inches total width). For height, measure from where the headrail will mount down to 2 inches below the window sill.
How many slats are in a 60-inch tall 2-inch faux wood blind?
A 60-inch tall blind with 2-inch slats contains approximately 30 horizontal slats plus bottom rail and valance components.
How much do custom faux wood blinds cost per window?
Standard 2-inch faux wood blinds cost $40 to $120 per window depending on size. Custom real wood or motorized cellular shades range from $150 to $400+ per window.
Is my personal data saved when using this calculator?
No. All calculations run strictly inside your web browser.