Curtain Size Calculator (Width, Length & Panels)

Q: What fullness should I choose for curtains?

For a balanced look, use 1.5× to 2× fullness for grommet and rod-pocket curtains, and 2× to 2.5× for pleated styles. Sheer fabrics often look best at 2× or more.

Q: What are common U.S. curtain lengths?

Popular ready-made lengths are 63, 84, 95/96, 108, and 120 inches. If your ideal length falls between sizes, size up and hem or choose the next longer length.

Q: How far should the rod extend past the window?

A typical guideline is 3–6 inches past each side of the window. Extending the rod makes the window appear larger and helps stack back the curtains without blocking light.

Q: How high should I mount the rod?

Mounting the rod 4–6 inches above the window is common. For a taller, more dramatic look, mount closer to the ceiling. Measure from the rod position down to the floor for accurate panel length.

Fast defaults below. Use Advanced options only if you want to fine-tune. Click Calculate for results.

Window Width (in)

Inside trim-to-trim window width.

Rod-to-Floor Height (in)

Measure from where the rod will sit down to the floor.

Curtain Style (auto fullness)

We auto-set fullness; adjust in Advanced if needed.

Number of Panels

Most windows use 2 panels.

Advanced Options (optional)

Unit System

Imperial is typical for U.S. measurements. Metric is available for convenience.

Rod Extension per Side (in)

Typical: 3–6 in each side.

Drop Style

Drop style uses inch presets: hover (−0.5"), kiss (0"), break (+1"), puddle (+6").

Heading Style

Used to suggest a fullness multiplier (if you want).

Fullness (×)

Typical: 1.5×–2× (grommet/rod pocket), 2×–2.5× (pleated), 2×+ (sheer).

Standard Panel Width Basis

Used to estimate how many ready-made panels will achieve your desired fullness.

Round Length Up to Nearest U.S. Standard

Standard lengths: 63, 84, 95/96, 108, 120 inches.

Show Secondary Units

If enabled, we’ll show the other unit system in parentheses.

Tip: The main calculator auto-sets fullness based on Curtain Style. If you change Fullness manually, your manual value is used.

Curtain Size Calculator — Get the Perfect Fit

Use this Curtain Size Calculator to calculate the correct panel width, panel length, and rod width for your window. Enter your measurements to see how many panels you need and what size to buy based on standard U.S. curtain dimensions and fullness.

How to Measure for Curtains

Measure window width: Inside trim to inside trim.
Choose rod extensions: Add 3–6 inches beyond each side to let panels stack off the glass.
Find rod height: Decide where you’ll mount the rod (often 4–6 inches above the window or higher for a taller look).
Measure rod to floor: From the rod location straight down to the floor.
Select a drop style: Hover, kiss, slight break, or puddle.
Pick fullness: 1.5×–2× for grommet/rod-pocket, 2×–2.5× for pleated, 2×+ for sheers.

Common U.S. Curtain Sizes

Ready-made lengths: 63″, 84″, 95/96″, 108″, 120″. Ready-made panel widths are commonly 50–54″ each.

If your ideal length falls between sizes, choose the next longer length and hem, or opt for custom panels.

Tips for a Professional Look

Mount rods higher to make ceilings feel taller.
Extend rods wider to visually enlarge the window.
Choose higher fullness for sheers and formal spaces.
Round up to the next length for “kiss” or puddled looks.

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Frequently Asked Questions

What fullness should I choose for curtains?

For a balanced look, use 1.5× to 2× fullness for grommet and rod-pocket curtains, and 2× to 2.5× for pleated styles. Sheer fabrics often look best at 2× or more.

What are common U.S. curtain lengths?

Popular ready-made lengths are 63″, 84″, 95/96″, 108″, and 120″. If your ideal length falls between sizes, size up and hem or choose the next longer length.

How far should the rod extend past the window?

A typical guideline is 3–6 inches past each side of the window. Extending the rod makes the window appear larger and helps stack back the curtains without blocking light.

How high should I mount the rod?

Mounting the rod 4–6 inches above the window is common. For a taller, more dramatic look, mount closer to the ceiling. Measure from the rod position down to the floor for accurate panel length.

Important Estimate Disclaimer

Results are provided for general planning and budgeting purposes only. Actual coverage may vary based on surface condition, layout complexity, waste allowance, and product specifications.

Refer to our Methodology and Data Sources for calculation assumptions.

Surface preparation, substrate irregularities, and installation methods may increase required material quantities.