How to Measure Windows for Curtains
Accurate window measurements are the first step to getting curtain fabric right. Measure wrong, and your curtains will be too short, too narrow, or both.
Good curtain fit starts with reliable measurements, not guesswork. This guide walks through the exact points to measure so you can avoid narrow panels, short drops, and costly recuts. You will measure width, drop, and hanging position in a consistent order. Once those numbers are set, fabric yardage becomes much easier to calculate correctly.
What You Need
- Steel measuring tape (not cloth, which can stretch)
- Step stool for high windows
- Paper and pencil to record measurements
Measuring Width
If the rod is already installed: Measure from one end of the rod to the other, excluding finials (the decorative end pieces). This is your curtain width.
If you are buying a new rod: The rod should extend 4–8 inches beyond the window frame on each side. This lets the curtains stack off the glass when open, maximising light and making the window appear wider.
For a track system: Measure the full track length.
Include returns if using a rod with brackets. A return is the distance from the front of the rod to the wall, typically 3–4 inches per side. Add both returns to the rod width to get the total curtain width.
Measuring Drop (Length)
The drop is measured from where the curtain will hang to where you want it to end:
| Drop Style | Where to Measure To | Typical Length |
|---|---|---|
| Sill length | Top of the windowsill | 36–45" |
| Below sill (apron) | 4" below the sill | 40–50" |
| Floor length (“kiss”) | 0.5" above the floor | 63–96" |
| Floor length (“break”) | 1–2" past the floor | 65–98" |
| Puddle | 6–12" past the floor | 72–108" |
Measure in Three Places
Floors and ceilings are rarely perfectly level. Measure the drop on the left, centre, and right of the window. Use the longest measurement. You can always hem shorter, but you cannot add length.
Where the Curtain Hangs From
- Rod pocket / tab top: Measure from the top of the rod.
- Rings / clips: Measure from the bottom of the ring (where the curtain attaches), not from the rod.
- Ceiling mount / track: Measure from the ceiling or track rail.
Common Mistakes
- Measuring the window frame instead of the rod. The rod is wider than the frame (or should be). Always measure where the curtain actually hangs.
- Forgetting returns. If the curtains need to wrap around the rod brackets to block light, add 3–4 inches per side.
- Only measuring once. Floors slope, walls bow. Measure in multiple places.
- Measuring from the wrong starting point. Ring-hung curtains start lower than rod-pocket curtains.
Next Step: Calculate Your Fabric
Once you have your window width and drop, feed them into our drapery yardage tool for exact yardage. It accounts for fullness ratio, header type, pattern repeat, and lining automatically.
If curtains are only part of the room refresh, head to the home page to total window, upholstery, and cushion fabric in a single order.