Calculate the perfect curtain dimensions for any window. Enter your window measurements, choose a length style and fullness level, and get recommended curtain rod width, panel width, curtain length, and number of panels instantly.
Curtain Size Calculator
Width Breakdown
Length Breakdown
Custom Fabric Estimate (if sewing your own)
Standard Curtain Sizes Reference
Most ready-made curtain panels come in standard widths and lengths. Use this table to find the closest match to your calculated measurements.
| Panel Width | Length | Best For | Typical Style |
|---|---|---|---|
| 42" (107 cm) | 63" (160 cm) | Small or cafe windows | Sill length |
| 50-54" (127-137 cm) | 63" (160 cm) | Standard windows, kitchens | Sill length |
| 50-54" (127-137 cm) | 84" (213 cm) | Standard windows, bedrooms | Below sill / floor |
| 50-54" (127-137 cm) | 96" (244 cm) | Tall windows, living rooms | Floor length |
| 50-54" (127-137 cm) | 108" (274 cm) | High ceilings, dramatic rooms | Floor / puddle |
| 100-110" (254-279 cm) | 84" (213 cm) | Wide/picture windows (single panel) | Floor length |
| 100-110" (254-279 cm) | 96" (244 cm) | Wide windows, high ceilings | Floor length |
Tips for Hanging Curtains to Make Windows Look Larger
- Mount the rod high: Hang your curtain rod 4-8 inches above the window frame, or even at the ceiling. This draws the eye upward and makes the window appear taller than it is.
- Extend the rod wide: The rod should extend 3-6 inches beyond each side of the window frame. When curtains are open, they stack on the wall -- not the glass -- letting in maximum light and making the window seem wider.
- Choose floor-length curtains: Even for short windows, floor-length curtains create an illusion of height. Avoid sill-length curtains in living rooms and bedrooms unless you have radiators or furniture blocking the way.
- Use the 2x fullness rule: Curtains that are twice the width of the rod create beautiful, full folds. Skimpy curtains look cheap and draw attention to the actual window size.
- Go light and bright: Light-colored curtains blend with the wall and make the overall window area feel larger. Dark, heavy curtains can make a small window feel even smaller.
- Use matching hardware: Mount the rod brackets at the same height as crown molding or just below the ceiling line. This creates a continuous visual line that elongates the wall.
- Avoid bunching at the bottom: Curtains that hover 1/2 inch above the floor look intentional and clean. Too-short curtains make the window look poorly fitted.
- Layer with sheers: Adding a sheer layer behind your main curtains adds depth, softness, and the illusion of a larger window treatment.
How the Curtain Size Calculator Works
Rod Width Calculation
The recommended curtain rod width is the window width plus 3-6 inches on each side. This calculator adds 6 inches to each side by default (12 inches total), allowing curtains to stack on the wall when open so they do not block the window glass.
Curtain Width (Fullness)
Total curtain fabric width = rod width multiplied by the fullness factor. For example, a 48-inch rod with 2x fullness needs 96 inches of total curtain fabric. This is then divided across the number of panels.
Curtain Length
Curtain length is measured from the rod down. It is calculated as: rod height above window + window height + length style adjustment. The adjustment depends on the style you choose:
- Sill length: Curtain ends at the windowsill (no extra length below the window)
- Below sill: Curtain extends 4 inches below the windowsill
- Floor length: Curtain extends to 1/2 inch above the floor
- Puddle: Curtain rests 2-3 inches on the floor for a luxurious look
Number of Panels
The calculator divides the total fabric width by a standard panel width of 50 inches (127 cm) and rounds up to the nearest even number. Most window treatments look best with an even number of panels -- one set on each side.
Custom Fabric Estimate
If you are sewing your own curtains, the calculator adds hem allowances: 3 inches per side seam (6 inches total width), 4 inches for a header/rod pocket, and 6 inches for a bottom hem. These allowances ensure professional-looking results.
Curtain Size Calculator FAQ
How wide should curtains be compared to the window?
Curtains should be 1.5x to 3x the width of the curtain rod, depending on the desired fullness. Standard fullness is 2x the rod width, meaning for a 60-inch rod you need 120 inches of total curtain fabric. This creates attractive folds when the curtains are closed.
How high above the window should I hang curtain rods?
Hang curtain rods 4 to 6 inches above the window frame for a standard look. To make windows appear taller, mount rods 8 to 12 inches above the frame or even at the ceiling. The higher the rod, the taller and more dramatic the windows will look.
What are the standard curtain lengths?
Standard curtain lengths are 63 inches (sill length), 84 inches (below sill or apron length), 96 inches (floor length), and 108 inches (puddled on floor). Floor-length curtains are the most popular and create an elegant look in most rooms.
How many curtain panels do I need per window?
Most windows use 2 panels (one on each side). Wide windows or picture windows may need 4 or more panels. Each panel should be at least half the rod width multiplied by the fullness factor. Standard panels are 50 to 54 inches wide.
Should curtains touch the floor?
Floor-length curtains should hover about half an inch above the floor for a clean look. For a casual puddle effect, add 1 to 3 inches of extra length. Curtains that are too short look awkward -- when in doubt, go longer rather than shorter.
What is the best curtain fullness for a modern look?
For a modern, clean look, use 1.5x fullness. For traditional or classic rooms, 2x to 2.5x fullness creates richer folds. Flat (1x) curtains work for minimalist spaces or roman shades but can look skimpy on large windows.
Can I use one panel per window?
Yes, a single panel pulled to one side works for small or narrow windows, asymmetrical designs, or modern minimalist rooms. For this look, the single panel should still have the full fabric width (rod width multiplied by the fullness factor).
How much extra fabric do I need for hems?
For custom curtains, add about 6 inches to the width (3 inches per side) and 10 inches to the length (4 inches for the header/rod pocket and 6 inches for the bottom hem). This calculator includes these allowances in the custom fabric estimate section.
Privacy & Limitations
- All calculations run entirely in your browser -- nothing is sent to any server.
- Results are estimates and may vary based on actual conditions.
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Curtain Size Calculator FAQ
How wide should curtains be compared to the window?
Curtains should be 1.5x to 3x the width of the curtain rod, depending on the desired fullness. Standard fullness is 2x the rod width, meaning for a 60-inch rod you need 120 inches of total curtain fabric. This creates attractive folds when the curtains are closed.
How high above the window should I hang curtain rods?
Hang curtain rods 4 to 6 inches above the window frame for a standard look. To make windows appear taller, mount rods 8 to 12 inches above the frame or even at the ceiling. The higher the rod, the taller and more dramatic the windows will look.
What are the standard curtain lengths?
Standard curtain lengths are 63 inches (sill length), 84 inches (below sill or apron length), 96 inches (floor length), and 108 inches (puddled on floor). Floor-length curtains are the most popular and create an elegant look in most rooms.
How many curtain panels do I need per window?
Most windows use 2 panels (one on each side). Wide windows or picture windows may need 4 or more panels. Each panel should be at least half the rod width multiplied by the fullness factor. Standard panels are 50 to 54 inches wide.
Should curtains touch the floor?
Floor-length curtains should hover about half an inch above the floor for a clean look. For a casual puddle effect, add 1 to 3 inches of extra length. Curtains that are too short look awkward, so when in doubt, go longer rather than shorter.