Curtain Size Calculator

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Curtain Size Calculator

1.5x (Tailored/Minimal) 2.0x (Standard/Full) 2.5x (Deluxe/Luxury) 3.0x (Sheer/Very Full)
1 (Single Panel) 2 (Pair of Panels)

Recommended Dimensions:

*Note: Measurements do not include fabric for hems or header allowance. Add approx. 10-20% extra fabric if sewing your own.
function calculateCurtainSize() { var rodWidth = parseFloat(document.getElementById('rodWidth').value); var curtainHeight = parseFloat(document.getElementById('curtainHeight').value); var fullness = parseFloat(document.getElementById('fullness').value); var panelCount = parseInt(document.getElementById('panelCount').value); if (isNaN(rodWidth) || isNaN(curtainHeight) || rodWidth <= 0 || curtainHeight <= 0) { alert("Please enter valid positive numbers for width and height."); return; } var totalWidthNeeded = rodWidth * fullness; var widthPerPanel = totalWidthNeeded / panelCount; document.getElementById('totalWidthResult').innerHTML = "Total Fabric Width: " + totalWidthNeeded.toFixed(1) + " (Total span across " + rodWidth + ")"; document.getElementById('panelWidthResult').innerHTML = "Width Per Panel: " + widthPerPanel.toFixed(1) + " (Buy " + panelCount + " panels of this width)"; document.getElementById('dropResult').innerHTML = "Finished Drop/Length: " + curtainHeight.toFixed(1); document.getElementById('curtainResult').style.display = 'block'; }

How to Use the Curtain Size Calculator

Choosing the right size for your window treatments is the difference between a high-end designer look and curtains that look skimpy or ill-fitted. This curtain size calculator helps you determine exactly how much fabric width you need based on your rod or track length.

Step 1: Measure Your Rod or Track Width

Always measure the width of the curtain rod or track, not the window itself. The rod usually extends 15-30cm (6-12 inches) beyond the window frame on each side to allow the curtains to be pulled back without blocking the glass. If you are using a rod with decorative finials, measure the distance between the finials.

Step 2: Determine the Fullness Ratio

Fullness refers to the amount of "gather" or waves in the fabric when the curtains are closed. Using a higher fullness ratio creates a more luxurious look.

  • 1.5x (Tailored): Best for modern, minimalist styles or heavy fabrics that don't drape well in large volumes.
  • 2.0x (Standard): The industry standard for most drapes. It provides a classic, pleated appearance.
  • 2.5x (Deluxe): Ideal for high-end window treatments and thinner fabrics like linen.
  • 3.0x (Sheer): Necessary for sheer curtains to ensure privacy and prevent the fabric from looking like a flat sheet.

Step 3: Measure the Drop (Length)

The "drop" is the finished length of the curtain. Decide where you want the curtains to end:

  • Sill Length: Ends 1.25cm (1/2 inch) above the window sill.
  • Below Sill: Ends 15cm (6 inches) below the sill to block light more effectively.
  • Floor Length: Ends 1-2cm above the floor for a clean look, or adds 5-10cm if you prefer a "puddled" effect.

Curtain Sizing Example

Suppose you have a curtain rod that is 200cm wide and you want a standard fullness (2.0x) using a pair of curtains (2 panels).

  1. Total Width: 200cm x 2.0 = 400cm.
  2. Panel Width: 400cm / 2 = 200cm per panel.
  3. Result: You should look for two panels, each with a width of 200cm.

Pro Tip: Fabric Width vs. Finished Width

If you are buying ready-made curtains, the width listed on the package is usually the flat width of the panel. If your window requires a total width of 300cm, you must ensure the sum of the flat widths of your purchased panels equals or exceeds 300cm. For eyelet (grommet) curtains, you often need at least 2.0x fullness to allow the "S" waves to form correctly on the rod.

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