Curtain Size Calculator
Calculate exact curtain panel width, total fabric requirements, and finished hanging length with fullness factor and hem allowances.
Window & Rod Setup
Enter window opening and hanging style
Recommended Curtain Dimensions
Fabric yardage and panel measurements
Single Panel Width
72 in
Total fabric gathered: 144 in
Finished Hanging Length
101.5 in
Cut length (with hems): 111.5 in
With a 2x fullness factor for Pencil Pleat (classic gathered headings), the total rod width of 72.0 in requires 144.0 in of gathered fabric divided across 2 panels.
How It Works & Calculation Formula
Step-by-Step Calculation:
- Calculate total track/rod span: Window Width + (Rod Overhang × 2).
- Multiply rod span by the fullness factor (1.5× for minimal, 2.0× for standard pleats, 2.5× for luxurious fullness).
- Divide total fabric width by the desired panel count (typically 2 panels) for individual panel widths.
- Calculate finished drop: Window height + rod height above frame, adjusted for sill, apron, or floor clearance.
- Add top and bottom hem allowances (typically 8–12 inches / 20–30 cm) for total cut fabric.
Worked Example Calculation
Sample Inputs:
- Window Width:60 inches
- Window Height:72 inches
- Fullness:2.0x (Standard)
- Style:Pencil Pleat
- Length:Floor Length
Expected Output:
Rod span: 72 in. Total fabric width: 144 in. Required: 2 panels of 72 in width each. Finished length: 101.5 in. Cut length with hems: 111.5 in.
Practical Tips & Trade Guidelines
- Hang the curtain rod 4 to 6 inches above the window frame (or halfway to the ceiling) to make ceilings appear taller.
- Extend the rod 6 to 12 inches on either side of the window frame so curtains can stack back cleanly and let maximum sunlight in.
- For sheer fabrics, choose 2.5× to 3.0× fullness to avoid a flat, insubstantial appearance.
- Allow floor curtains to hover 0.5 inches above the floor for easy vacuuming, or puddle 1–2 inches for romantic drama.
Frequently Asked Questions
Important Renovation Notice
Calculations are mathematical estimates based on standard trade conventions. Always field-verify room measurements, examine packaging labels, and check with a licensed contractor before purchasing materials or starting installation.