How to measure curtains
Measure three things, in inches: each window width, the wall run, and the rod height to floor. Write each number down before you open a planner.
Test draft note: the measuring points on this page have not yet been checked against manufacturer measuring guides. That check is still to verify before any live publication.
What you need
- A tape measure
- A pencil and paper
- A step ladder, if the rod height is out of reach
Measuring table, by layout
| Layout | What to measure | From and to |
|---|---|---|
| Bay window | Each of the three window widths, then the wall run | Outside edge to outside edge, including molding, for each window, then the full wall run |
| Sliding door | Door width, then the wall run | Outside edge to outside edge of the door frame, then the full wall run |
| Several windows on one wall | Each window width, each gap between windows, then the wall run | Outside edge to outside edge, including molding, for each window and each gap, then the full wall run |
| Every layout | Rod height to floor | Where the rod will sit, straight down to the floor |
Common mistakes
- Measuring the glass only, and leaving out the molding and frame.
- Measuring one bay window, and not the whole run.
- Measuring the wall, and not the height where the rod will sit.
Worked measuring example
A bay run with left 36 inches, centre 48 inches, and right 36 inches has a window sum of 120 inches. If the wall run you measure is also 120 inches, those are the numbers you enter in the bay planner. If your wall run is larger, enter the wall run you measured, not the window sum.
Doubts to settle before you measure
Do I measure the glass, or the whole window? Measure outside edge to outside edge, including molding, for each window, then the full wall run. Measuring the glass only is the most common mistake on this page, because the rod and the panels must cover the frame, not just the glass.
Do I measure one bay window, or the whole run? Measure each of the three windows, and the wall run as well, and enter the wall run you measured in the bay planner, not the window sum, if the two differ. A plan built from one window alone cannot give a whole-run rod length.
How many panels do I need? That is not a measuring question alone. It comes from the plan: total panel width divided by the panel width you want to buy, rounded up. For a worked case, wall run 120, fullness 2, panel width wanted 50 gives total 240, 5 panels, 48 inches each. Enter your own numbers in a planner for your own answer.
Next step
Use the bay window curtain planner, the sliding door curtain planner, or the multi-window wall curtain planner with the numbers you just measured.