Measurement Guide

How to Measure for Curtains?

Use this guide to turn your rod or track measurements into the width and length you enter for each curtain panel. For the most reliable result, install or select your hardware first and measure in inches with a steel tape.

Before you start: Confirm the header style, number of panels, and intended floor finish on the product page. Different headers use different width and length reference points.

Step 1: Plan and Measure the Rod or Track

Existing hardware: Measure the usable span that the curtains will cover. For a rod, measure between the outer points where the panels can travel; do not include decorative finials. For a track, measure the working track length.

New hardware: When the wall and surrounding features allow, a rod or track is commonly positioned 6–10 inches above the window frame and extended 6–15 inches beyond each side. The side extension creates stack-back space so open curtains cover less glass. Treat these as planning ranges—not fixed requirements—and follow the hardware manufacturer’s installation limits.

Mark both mounting points, confirm they are level, and record the total usable width.

Curtain rod positioned above and beyond a window with measurement arrows — Plan both the mounting height and the side extension before calculating panel width.

Step 2: Calculate the Width for Each Panel

Use the formula that matches your selected header. Always divide by the number of panels you plan to order.

Flat headers

For grommet, rod pocket, back tab, tab top, and flat-panel styles, the fabric forms waves after hanging. Use:

Width per panel = usable rod or track width × desired fullness ÷ number of panels

A fullness of about 1.5× to 2× is commonly used for flat headers; select the amount of fullness that suits the look and the options shown on the product page.

Pre-pleated headers

For pinch pleat, Euro pleat, tailored pleat, inverted pleat, and goblet pleat styles, the pleat fullness is sewn into the panel. Do not add the fullness a second time.

Width per panel = usable rod or track width ÷ number of panels

Ripple fold

Use the track coverage width divided by the number of panels. Ripple-fold performance also depends on compatible carriers, snap spacing, and track specifications, so confirm your hardware before ordering. The lower edge may spread wider than the measured top coverage.

Example: For a 100-inch usable span with two panels, a flat header at 2× fullness requires 100 inches per panel: (100 × 2) ÷ 2. A pre-pleated pair requires 50 inches of coverage per panel: 100 ÷ 2.

Step 3: Measure the Curtain Length

Measure from the reference point created by your selected hardware to the floor. Because the top edge sits differently on each system, use the matching reference below:

Grommet: Measure from the top of the rod to the floor, then include the fabric that will sit above the grommet opening as specified on the product page.
Rod pocket, back tab, or tab top: Measure from the intended finished top position of the panel to the floor, allowing for how the chosen header sits on the rod.
Pleated curtains with hooks or rings: Measure from the planned hook or ring attachment point to the floor, following the hardware and hook-position guidance for the selected product.
Ripple fold: Measure from the bottom of the installed carrier or track reference point to the floor, according to the track system.

Choose the floor finish

Float: Subtract 1/2 inch so the hem clears the floor.
Kiss the floor: Use the measured base length with no added length.
Soft break or puddle: Add 2–4 inches, depending on the fabric and the amount of pooling you prefer.

Curtain length comparison showing float, floor-touching, and puddled hems — From left to right: a small floor clearance, a floor-touching hem, and a controlled soft puddle.

Final Measurement Checklist

Measure every window or opening separately, even when they appear identical.
For floor-length curtains, measure at the left, center, and right. Use the shortest measurement for a clean float or floor-touching finish.
Record measurements to the nearest 1/8 inch, then select the nearest available increment shown on the product page.
Check baseboards, radiators, handles, vents, and furniture that could affect the curtain path or hem.
Do not add or subtract manufacturing allowances unless the product page specifically instructs you to do so.

Need help with an unusual window or track? Email info@diycurtain.com before ordering and include photos of the full window, hardware, and nearby obstructions. Custom curtains are produced from the measurements and options submitted with the order.