Curtain Fabric Calculator
Calculate total yardage for curtain panels including fullness, hems, and heading allowances.
Results are estimates. Always add extra for shrinkage, mistakes, and pattern matching.
How to Use the Curtain Fabric Calculator
Enter your window measurements and preferences. The calculator handles all the math for fullness, hems, and heading allowances.
Key Terms
- Window Width: Measure your rod from end to end, not just the window glass.
- Drop: Distance from rod to where curtain should end (floor, sill, or apron).
- Fullness Factor: How gathered/full the curtains will look. 2× is standard for most fabrics.
- Heading: The top treatment. Rod pocket and tab-top need extra fabric for the pocket/tabs.
Fullness Guide
| Factor | Look | Best For |
|---|---|---|
| 1.5× | Minimal gather | Sheer fabrics, modern style |
| 2× | Standard | Most fabrics and styles |
| 2.5× | Full | Heavier fabrics, formal look |
| 3× | Very full | Luxurious draping, velvet/silk |
About this Curtain Fabric Calculator
Curtain yardage comes from multiplying several allowances together, not just adding them: each panel's cut width is the rod-width share times your fullness factor, and its cut length is the drop plus heading and hem allowances. Because fullness is multiplicative on the width side, it has a bigger effect on total yardage than any single heading or hem choice — going from 2× to 3× fullness increases the fabric needed by 50%, while switching heading styles only changes a few inches per panel.
Measure the rod, not the window
Window Width here means the curtain rod's end-to-end length, which is usually wider than the window glass itself so the curtains can stack fully open beside it — using the glass measurement will undersize your panels. If you're piecing fabric to reach a panel's full width, remember that each seam also needs its own seam allowance, which this calculator doesn't add automatically. See the Fabric Yardage Calculator for other home-dec projects.