Curtain Length Calculator – Find the Perfect Curtain Size for Your Windows

Get perfectly sized curtains every time with our Curtain Length Calculator. Enter your window height and width along with your preferred drop and fullness ratio to calculate the exact fabric dimensions needed.

Unit System

Window Height

Window Width

Rod Height (from floor)

Rod Width (total)

Curtain Length Style

Header Style

Fullness Ratio

Higher fullness = more luxurious gathers

Curtain Size Results

Enter values and click Calculate to see results

Curtain Measuring Guide

Curtain Length = Rod Height + Header Allowance + Bottom Hem

Curtain Width = Rod Width × Fullness Ratio

Panels Needed = Total Width ÷ Standard Panel Width (50")

Style	Description
Floor	1/2" above floor - most popular
Sill	Ends at windowsill - kitchens/baths
Apron	4" below sill - traditional look
Puddle	6-12" extra on floor - formal/dramatic

How the Curtain Length Calculator Works

Measure Your Window

Enter window height and width, plus rod height from floor for accurate curtain length calculation.

Choose Style Options

Select curtain length style (floor, sill, apron, puddle), header type, and fullness ratio.

Get Perfect Curtain Size

Receive recommended curtain dimensions, number of panels needed, and total fabric requirements.

Features of This Curtain Calculator

Multiple Length Styles

Calculate floor-length, windowsill, apron, or puddle style curtains with appropriate hem allowances.

Header Style Options

Account for grommet, rod pocket, pleated, or tab top header allowances in calculations.

Fullness Ratio Control

Choose from economy (1.5x) to extra full (3x) for desired curtain gather appearance.

Panel Count Calculator

Automatically calculates number of standard panels needed based on total width required.

Inch and CM Support

Work in inches or centimeters with automatic conversions for international users.

Free Home Decor Tool

Completely free curtain calculator for DIY decorators and professional designers.

Curtain Length Style Guide

Style	Description	Best For
Floor	1/2" above floor	Living rooms, bedrooms (most popular)
Sill	Ends at windowsill	Kitchens, bathrooms, casual spaces
Apron	4" below sill	Traditional look, radiators below
Puddle	6-12" extra on floor	Formal rooms, dramatic effect

Frequently Asked Questions

How do I measure for curtain length?

Measure from the bottom of the curtain ring (or top of rod) to your desired endpoint. For floor-length, measure to 1/2" above floor. For sill-length, measure to the windowsill. Always measure from where curtains will hang, not the top of the finial.

What is the standard curtain fullness ratio?

Standard fullness is 2x the window width, creating attractive gathers. Economy (1.5x) looks flatter, while luxury (2.5x) and extra full (3x) create richer, more dramatic folds. Higher fullness requires more fabric and panels.

How high should I hang curtain rods?

Mount rods 4-6 inches above the window frame to make windows appear taller. Extend rods 3-6 inches beyond each side so curtains don't block light when open. For high ceilings, mount rods halfway between window top and ceiling.

How many curtain panels do I need?

Divide your total width needed (rod width x fullness ratio) by standard panel width (typically 50"). For a 60" rod with 2x fullness: 120" / 50" = 2.4, so you need 3 panels per side or 6 total for a pair.

What is the difference between grommet and rod pocket curtains?

Grommet curtains have metal rings for easy sliding and modern look, requiring ~3" header. Rod pocket curtains have a sewn channel for the rod, creating a gathered look with ~4" header. Grommets work better for frequent opening/closing.

Other Free Tools

Search tools