How to Calculate Roman Blind Rod Pockets: Count, Width & Placement

What Rod Pockets Do

Roman blind rods (flat fibreglass or metal rods) are inserted into horizontal pockets sewn across the back of the blind at each fold line. The rods:

• Keep the fold lines perfectly straight and horizontal
• Add weight so folds hang evenly
• Prevent the fabric from pulling to one side when cords are pulled

Number of rods = number of folds. The Roman Blind Calculator gives you both numbers automatically.

Rod Count Formula

Sections = round(finished drop ÷ fold spacing)
Folds    = sections − 1
Rods     = folds

The top section and bottom section do not need rods (top is fixed to batten; bottom is the hemmed edge). Only the interior fold lines need rods.

Bold = most common residential blind configuration.

Rod Pocket Width

Each rod pocket is a horizontal channel sewn on the back of the blind.

Standard rod pocket width:

Bold = most common rod size for standard DIY roman blinds.

The rod pocket is formed by a strip of lining or interlining tape sewn across the back. The rod slides inside the finished pocket.

Important: Rod pocket width is NOT added to the cut length formula. Rod pockets are made from separate strips or formed from the lining attachment, not from the face fabric length.

Rod Pocket Placement

Rod pockets are positioned at each fold line, measured from the top of the finished blind (excluding the batten allowance).

Pocket centre position from top of finished blind:

Position of rod n = n × section_height

Example: 120 cm drop, 5 sections, 24 cm actual spacing:

The pocket is centred on this line. For a 4 cm pocket, the pocket extends 2 cm above and below the fold line mark.

How Rod Pockets Are Made

Method 1: Ring tape with built-in pockets

Roman blind ring tape (available from fabric shops) has pre-formed loops at regular intervals and integral rod pockets woven in. You sew the tape vertically down the back of the blind. The pockets align automatically if you start at the same point on each tape.

Advantage: Fast, accurate, no manual pocket sewing required.

Method 2: Separate lining strips

Cut strips of lining fabric 5–6 cm wide × blind width. Fold each strip in half lengthwise. Sew the strip across the back of the blind at each fold line, creating a pocket for the rod. This is more flexible if you want pocket spacing that doesn’t match commercial tape intervals.

Method 3: Sewn tucks in the lining

For lined blinds, the lining itself can be sewn in tucks at each fold line, forming pockets without separate strips. For lining types and cut sizes, see the Roman Blind Lining Guide. Sew across the lining at each fold position, leaving the pocket open on one side for rod insertion.

Rod Length

Rods are cut to length (or purchased at length) equal to:

Rod length = finished blind width − 2 cm (0.8")

The rod sits 1 cm (0.4”) short of each side hem. This prevents the rod ends from creating visible ridges at the side edges.

For fibreglass rods (most common for DIY): cut with wire cutters. Sand the cut end smooth.

Rings: Placement Alongside Pockets

Rings (for the cords) are attached at each rod position, not in the pockets themselves — usually just above or just below each rod pocket. Rings are spaced in vertical rows:

Bold = most common for wide sitting room blinds.

The first row is typically 3–5 cm from each side edge. Remaining rows are spaced evenly across the width.

Use the Roman Blind Calculator to get fold count and spacing for your rod pocket placement.

See also: How to Calculate Roman Blind Folds and Roman Blind Fabric Formula.