Functional Vs. Decorative Drapes
How to Determine Width of Drapes you will need
How to Calculate Length of Drapery Rod
Functioning Drapes
If you want functioning drapes to cover the window and also the entire rod when the drapes are closed, you would refer to the chart below to calculate the approximate length of the rod you would need.
Stack Back is the approximate amount of space the drapes take up when they are fully open. This measurement varies depending on whether you stack the pleats close together or spread them out with more space between the pleats. Light weight fabrics will stack tighter together than heavier weight fabrics, and the type of lining used will also affect the stack.
If you want all of the glass exposed on the window, and you don’t want the drapes to block any glass or light, and you want the drapes to stack on the wall on each side of the window, then the totals below would tell you how long of a rod you would need to achieve that.
The Stack Back number listed below is the total of both sides, so you would divide that by 2 and that is how far your rod would extend past each side of the window. For example if your window is 54” wide and the Stackback is 30”, divide that by 2 which is 15”. Your rod would be 84” long, extending 15” past each side of the window. You would need Double Width Drapes.
If your budget only allows for 1 ½ Width Drapes, then you would use a 60” rod for functioning drapes. 1 ½ Widths has an approximate stack of 12” on each side with the pleats tightly stacked together, so some of the drapes will cover the glass, but when the drapes are closed they will cover the whole 60” long rod.
Also, if you do not have enough wall space on one or both sides of the window, then calculate the maximum length of the rod you would need to accommodate whatever wall space is available. In this scenario, more of the glass would be covered by the drapes. Instead you would calculate the maximum rod length you have room for. The length of the rod would indicate the width of the drapes you would need in order to cover the whole rod if these are functioning and not decorative drapes. (See Drapery Width Chart Below)
For functioning drapes, below are approximate numbers of pleats used and the span of total coverage for each width. This is based on the fabric being at least 54” wide. Narrower fabrics will have smaller coverage and fewer pleats. This is also helpful in determining the length of the rod you would use based on the width of the drapes that fit in your budget. For more expensive fabrics, narrower widths with shorter rods may be preferable. The numbers in RED below would be total length of the drapery rod for each corresponding width of drapes. For example if your window is 75” wide, but you only can afford double width drapes, then the rod would need to be 80-90” (instead of 110” shown on Stack Back Chart which would require 2 ½ Width Drapes)
Decorative/Non-Functioning Drapes
If your drapes are only decorative and you will not be closing them, the stack is so you can determine how much of your window you want covered when the drapes are open, and how long of a drapery rod you will need to achieve that.
See Examples of Drapery Widths Here.
DRAPERY WIDTH CHART
Single Width Pleated Drapes
Number of Pleats per Panel – Triple Pleat - 5; Double Pleat - 6
1 Pair of Single Width Pleated Drapes will cover a total span of 40-46”depending on whether you use a triple or double pleat.
Approximate Stack per side 10-16” – Pleats tight together vs. spread out.
1 1/2 Width Pleated Drapes
Number of Pleats per Panel – Triple Pleat - 7; Double Pleat - 8
1 Pair of 1 1/2 Width Pleated Drapes will cover a total span of 60-68”depending on whether you use a triple or double pleat.
Approximate Stack per side 12-20” – Pleats tight together vs. spread out.
Double Width Pleated Drapes
Number of Pleats per Panel – Triple Pleat - 10; Double Pleat – 11-12
1 Pair of Double Width Pleated Drapes will cover a total span of 80-90”depending on whether you use a triple or double pleat.
Approximate Stack per side 15-25” – Pleats tight together vs. spread out.
2 1/2 Width Pleated Drapes
Number of Pleats per Panel – Triple Pleat - 12; Double Pleat – 13-15
1 Pair of 2 1/2 Width Pleated Drapes will cover a total span of 100-115”depending on whether you use a triple or double pleat.
Approximate Stack per side 17-27” – Pleats tight together vs. spread out.
Triple Width Pleated Drapes
Number of Pleats per Panel – Triple Pleat - 15; Double Pleat – 16-18
1 Pair of Triple Width Pleated Drapes will cover a total span of 120-130”depending on whether you use a triple or double pleat.
Approximate Stack per side 19-29” – Pleats tight together vs. spread out.
3 1/2 Width Pleated Drapes
Number of Pleats per Panel – Triple Pleat – 18-19; Double Pleat – 20-21
1 Pair of 3 1/2 Width Pleated Drapes will cover a total span of 135-150”depending on whether you use a triple or double pleat.
Approximate Stack per side 20-30” – Pleats tight together vs. spread out.
Quadruple Width Pleated Drapes
Number of Pleats per Panel – Triple Pleat - 21; Double Pleat – 22-24
1 Pair Quadruple Width Pleated Drapes will cover a total span up to 200”depending on whether you use a triple or double pleat.
Approximate Stack per side 26-36” – Pleats tight together vs. spread out.
STACK BACK CHART
Find your window opening _____ Example (36”)
Stack Back Total for Both sides _______ Example (24”)
Total Length of Rod Needed _____Example (60”)
Window Opening Stack Back Both Sides Total Rod Length
24 20 44
30 23 53
36 24 60
38 25 63
42 26 68
44 27 71
48 29 77
54 30 84
60 31 91
66 32 98
68 33 101
72 34 106
75 35 110
78 36 114
84 37 121
90 38 128
96 39 135
100 41 141
102 42 144
106 43 149
108 44 152
114 45 159
120 48 168
126 49 175
132 51 183
138 52 190
144 54 198
150 55 205
Free PDF of our drapery width guide, available for download here.