Enter your rod width and the drop to the floor or sill. See the width and length of each panel and how many ready-made panels to buy.
Curtain length
Panel layout
Enter your measurements
Curtain rod width (without finials)
Drop from rod to floor
Using rings? Measure from the bottom of the rings.
Size of each panel (2 panels)
Total width across all panels: 144 in (2x your rod width).
Fullness and length
Fullness (width ÷ rod)
2xAbout 2x is a common starting point for soft folds.
Length adjustment
-0.5 inAdded to your drop. Default for floor length: -0.5 in.
Ready-made panels to buy
Panel width
Panels
4
Length
84 in (213 cm)
Rounded up to an even number so both sides match. The count is your total width divided by the panel width, rounded up. Pick the next length up and hem it: you can shorten a panel, but you can’t lengthen one.
TIP
Floor-length panels usually end about ½ inch above the floor so the hem doesn’t drag or collect dust.
How to measure windows for curtains
Curtain size depends on your rod, not the glass. Width comes from the rod length times a fullness factor. Length comes from the drop between the rod and the floor or windowsill.
This calculator takes your rod width, your drop, and a few choices: floor, sill, or below-sill length, one panel or a pair, and fullness. It returns the size of each panel and how many ready-made panels to buy. You can switch between inches and centimeters at any time.
Run the numbers before you shop, so you know whether 84-inch or 95-inch panels fit and how many you need.
When a quick sizing check helps
Before you move in
Measure the rod and the drop during a walk-through, then work out the panel size and count before the boxes arrive.
Replacing old curtains
Check whether your current panels are too short, too narrow, or too flat for the rod, and what to order instead.
Ordering panels online
Know the width, length, and panel count to look for before you scroll through dozens of listings.
Comparing fullness and budget
Switch between 1.5x, 2x, and 2.5x to see how the panel count, and the cost, changes.
Find your curtain size in 4 steps
- Pick a curtain length (floor, light puddle, sill, or below the sill) and a layout (pair or single panel).
- Enter your rod width and the drop from the rod to the floor or windowsill. Use the Inches / cm switch if you prefer metric.
- Set the fullness. 2x is the default. Adjust the length if you want a shorter or longer hem.
- Read the size of each panel and the number of ready-made panels to buy, then copy the results.
Note: The calculator runs in your browser, so nothing you enter is sent anywhere.
Measuring tips and limits
- Results are estimates. Check the size chart on the product page before you buy.
- Measure the rod itself, without the finials. If you use rings or clips, measure the drop from the bottom of the rings.
- Some pleated curtains are sold with fullness already built into the listed width. Check the listing before you use the panel count.
- Results are finished sizes. They don’t include extra fabric for hems or headers, so add those separately if you are sewing your own.
- The ready-made match uses widths of 48, 50, and 54 inches and lengths of 63, 84, 95, 108, and 120 inches. Brands vary, so sizes can differ.
Length styles and the default adjustments
The calculator adds the adjustment to your measured drop. You can change it with the length buttons.
| Style | Measure rod to | Default adjustment | What it does |
|---|---|---|---|
| Floor length | Floor | −½ in (−1.3 cm) | Leaves a small gap so the hem doesn’t drag |
| Light puddle | Floor | +2½ in (+6.4 cm) | Lets the hem rest on the floor |
| Sill length | Windowsill | −½ in (−1.3 cm) | Stops just above the sill |
| Below the sill | Windowsill | +4 in (+10.2 cm) | Covers the trim; 4 to 8 in is common |
These are common starting points, not rules. Your rod type, hardware, and preferred look can change the final length.
Curtain width, length, and panel count explained
How each number in the results is calculated.
Measure the rod, not the glass
Rods usually run past the window frame so open panels can stack off the glass. That is why the rod width is your starting point. Measure the rod without the finials, then multiply by your fullness.
Fullness: why total width is more than the rod
Fullness is the total fabric width divided by the rod width. About 1.5x to 2x is typical, and 2x is a common default for gathered folds. Pleated or formal drapes often go to 2.5x. Low fullness can look flat when the curtains are closed.
Pair or single panel
Total width is rod width × fullness. For a pair, each panel is half of that. A single panel carries the full width. To buy ready-made, divide the total by the panel width and round up. For a pair, the calculator rounds up to an even count.
Ready-made or custom
Ready-made panels come in a handful of lengths, commonly 63, 84, 95, 108, and 120 inches. Choose the next size up and hem it, because you can shorten a panel but not lengthen it. If your window or rod height is unusual, a custom size avoids the compromise.
Common curtain measuring mistakes
Measuring the window instead of the rod
Panels sized to the glass are too narrow for the rod, so they leave gaps at the sides and don’t stack off the window when open.
💡 See the solution▼
Buying panels with no fullness
Panels that only match the rod width hang flat and look like a stretched sheet when closed.
💡 See the solution▼
Measuring length from the wrong point
If you hang panels on rings, the top of the fabric sits below the rod, so a measurement from the rod makes the curtain too long.
💡 See the solution▼
Buying a panel that is too short
A short panel can’t be lengthened, so the hem ends well above the floor or sill.
💡 See the solution▼
Curtain sizing FAQ
Q.How do I measure for curtains?
A. Measure the curtain rod, not the window. Use the rod length without the finials for width. For length, measure from the top of the rod down to the floor or the windowsill. If you hang curtains from rings, measure from the bottom of the rings instead.
Q.How wide should curtains be?
A. Total curtain width is usually 1.5 to 2 times the rod width, so the fabric forms folds instead of hanging flat. This calculator starts at 2x. Fuller looks, such as pleated or formal drapes, often go up to 2.5x. You can set any value from 1x to 3x.
Q.How many curtain panels do I need?
A. Multiply your rod width by the fullness you want, then divide by the width of one ready-made panel. Common ready-made panels are 48, 50, or 54 inches wide. Round up. If you hang a pair, the calculator rounds up to an even number so both sides match.
Q.How long should curtains be?
A. It depends on the look. Floor-length curtains usually end about ½ inch above the floor. Light puddled curtains rest on the floor. Sill-length curtains stop about ½ inch above the sill, and curtains that hang below the sill commonly extend 4 to 8 inches past it. The calculator sets a default for each style, and you can adjust it.
Q.What size curtains do I need for a 72-inch rod?
A. At 2x fullness, the total width is 144 inches, or 72 inches per panel in a pair. With 50-inch ready-made panels, 144 ÷ 50 rounds up to 3, and a pair needs an even number, so you would buy 4 panels. That gives 200 inches of fabric, about 2.8x your rod width.
Q.What are the standard curtain sizes?
A. Ready-made panels are commonly sold in lengths of 63, 84, 95, 108, and 120 inches, and in widths of about 48 to 54 inches per panel. This calculator matches your length to the next size up. If your length is over 120 inches, it suggests a custom length.
Q.Does the calculator send my measurements anywhere?
A. No. The math runs in your browser, so the numbers you enter are not sent to a server or saved.
Q.Can I use centimeters instead of inches?
A. Yes. Switch the unit above the measurement fields and your values convert. Ready-made sizes are shown in inches with centimeters in parentheses, since that is how most ready-made panels are listed.
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