🪟Curtain Size Calculator
Calculate the correct curtain width and length for your windows. Choose curtain type (sill, floor, café, extra long), fullness level (standard, deluxe, ultra), and number of panels. Shows finished curtain dimensions plus extra fabric needed for hems and headers.
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Width × Length per Panel
112.5 cm × 233.5 cm
Curtain Dimensions
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Curtain Size Calculator: How to Measure and Choose the Right Curtains
Curtain width = Window width × fullness factor ÷ panels. Curtain length = rod height above window + window height + desired drop below. Standard fullness (1.5×) creates a gentle gather; deluxe (2×) creates medium folds; ultra (2.5×) creates luxurious pleats. Always add 20 cm to length for hem and header finishing.
Example: 150 cm wide window, 2 panels, standard fullness: 150 × 1.5 = 225 cm total ÷ 2 = 112.5 cm per panel
| Curtain Type | Drop from Rod | Best for |
|---|---|---|
| Sill length | Rod to sill + 1.5 cm | Kitchens, casual spaces |
| Floor length | Rod to floor − 1.5 cm | Living rooms, bedrooms |
| Extra long | Rod to floor + 15 cm | Formal rooms, drama |
Properly sized curtains transform the look of a room. Curtains hung too low or narrow look cramped; curtains hung wide and high from floor to ceiling make rooms appear taller and more expansive. The industry standard is to mount the rod 10–20 cm above the window frame and extend it 15–30 cm wider than the window frame on each side so the panels clear the glass when open.
How to Measure for Curtains
Step 1: Install or plan the position of your curtain rod — typically 10–20 cm above the window frame and 15–30 cm wider on each side. Step 2: Measure the width of the rod or track (not the window). Step 3: Decide your curtain length style (sill, apron, floor, or extra-long/puddle). Step 4: Measure from the rod to the desired endpoint. Step 5: Multiply the rod width by your fullness factor (1.5×–2.5×) to determine total fabric width. Step 6: Add hem allowances: 10 cm for the bottom hem and 10 cm for the top header or rod pocket.
Frequently Asked Questions
How do I calculate what size curtains I need?
Measure your window width and multiply by the fullness factor to get the total curtain width. Standard fullness (×1.5) is good for most rooms; deluxe (×2) creates full, lush folds. Divide by the number of panels (usually 2). For length, measure from where the rod will hang to your desired endpoint: sill = bottom of window + 1.5 cm; floor = floor − 1.5 cm clearance; puddle/extra long = floor + 15 cm. Add 20 cm (or 8 inches) to the length for hem and header allowances when buying fabric or checking ready-made sizing.
How high above the window should the curtain rod be?
Mount the rod 10–20 cm (4–8 inches) above the top of the window frame. For low ceilings, mount higher (up to 5–10 cm from the ceiling) to visually add height. For standard 8-foot ceilings, 15 cm above the window is the most common recommendation. Extend the rod 15–30 cm (6–12 inches) beyond the window frame on each side so the panels can be pulled completely clear of the glass — this maximises light when the curtains are open and makes the window appear wider.
What is the difference between standard, deluxe, and ultra fullness?
Fullness refers to how much extra fabric width is used relative to the window width, creating folds and volume. Standard fullness (×1.5): the fabric is 1.5× the window width, creating a light gather — good for casual, airy looks with lightweight fabrics. Deluxe fullness (×2): fabric is twice the window width — medium folds, works well for most medium-weight fabrics and gives a classic look. Ultra fullness (×2.5–3): very generous folds — best for sheer or lightweight fabrics and formal, luxurious settings. Heavier fabrics naturally drape more voluminously, so they need less fullness.
Should curtains touch the floor?
It depends on the style and room use. Floor-length curtains (1.5 cm above the floor) are clean and practical — good for frequently opened curtains and homes with children or pets. Puddle curtains (15–30 cm extra on the floor) look romantic and formal but are less practical and harder to clean. Sill-length curtains (to the windowsill) are casual and work well in kitchens and bathrooms. Apron-length (10 cm below sill) is between sill and floor — a dated style now less common. Interior designers generally recommend floor-length for living rooms and bedrooms for an elegant, finished look.