Curtain Size Calculator
Find the finished curtain width and the approximate length needed for a common window treatment style.
This helps with planning before you buy fabric, cut panels, or hang a new rod.
Result
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Run the calculation to see the curtain size.
Quick Answer
Curtain width is usually the window width multiplied by fullness. Curtain length depends on the style you want, such as sill, apron, floor, or puddle length.
How to Use It
- Pick your unit.
- Enter the window width and height.
- Choose the curtain style and fullness.
- Click Calculate.
Formula
Curtain width = window width x fullness
Curtain length = window height + style allowance
Worked Examples
Example 1: A 60-inch window at 2x fullness needs 120 inches of total curtain width.
Example 2: A floor-length style adds a larger drop than an apron-length style.
Example 3: A 48-inch window with a 1-inch allowance gives a 49-inch sill-length estimate before hems.
How to Interpret Your Results
| Output | Meaning | Action |
|---|---|---|
| Curtain width | The total width needed for the chosen fullness. | Use it to choose fabric width and number of panels. |
| Curtain length | The approximate drop from the top to the hem. | Adjust hems and heading style before cutting. |
| More fullness | The curtain will gather more when closed. | Increase fullness for a richer look. |
Frequently Asked Questions
Pick the style that matches where you want the curtain to end, such as the sill, apron, floor, or just below the floor.
Yes. The calculator includes a simple extra allowance, but you can still add more if your sewing method needs it.
Yes. Use the total width and divide it across the number of panels you plan to sew.
Related Calculators
References
- OmniCalculator reference page
- The calculator combines window measurements with fullness and style-based allowances.
- Last reviewed: March 2026.