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 inches. 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.

Curtain Size Calculator - Rod Width, Panel & Drop

Unit System

U.S. users typically measure in inches. Metric is available for convenience.

Window Width (in)

Inside trim-to-trim window width.

Rod Extension per Side (in)

Typical: 3–6 in each side.

Rod-to-Floor Height (in)

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

Drop Style

Adjusts panel length relative to rod-to-floor height.

Measurement guide: window width, rod extensions, and rod-to-floor height.

Heading Style

Used to suggest a fullness multiplier.

Fullness (×)

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

Number of Panels

Most windows use 2 panels.

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 Metric Equivalents

Curtain Size Calculator — Get the Perfect Fit

Use our free Curtain Size Calculator to quickly determine the right rod width, curtain panel width, and panel length for your windows. Enter your window width, rod-to-floor height, side extensions, heading style, and fullness. The calculator estimates per-panel width, total coverage, and suggests the nearest U.S. standard curtain lengths so you can shop confidently online or in-store.

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 (−0.5″), kiss (0″), slight break (+1″), or puddle (+6″).
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.

Related Tools

Planning other projects? Try our Concrete Slab Calculator and Gravel Calculator.

FAQs

What fullness should I choose?
1.5×–2× for grommet and rod pocket, 2×–2.5× for pleated, and 2×+ for sheers.

What’s the best rod height?
4–6″ above the window is common; higher mounting elongates the room.

How many panels do I need?
Most windows use two panels; wide spans or higher fullness may require more.

Important Estimate Disclaimer

The results provided by this calculator are intended as general estimates only and should not be considered precise engineering measurements. Actual material requirements, costs, and quantities can vary significantly based on site conditions, local building codes, soil type, reinforcement requirements, climate exposure, and the intended use of your project.

These calculators are designed to help you plan and budget your project more effectively, but they do not replace professional advice from a qualified contractor, engineer, or building inspector. Always verify your calculations and assumptions with trained professionals before placing material orders or commencing construction.

For more information on the assumptions, formulas, and data used in these tools, see our Data Sources and Methodology pages.

Material estimates, cost figures, and volume calculations are approximate and may not reflect your actual requirements. Always double-check dimensions and project-specific needs, and consider adding a contingency allowance for waste, over-excavation, and unforeseen conditions.

If you are unsure about any aspect of your project — including structural requirements, reinforcement needs, drainage, or load-bearing capacity — consult with a licensed professional before proceeding.