Grommet Curtains Fabric Requirements: What You Need to Know

Grommet vs Eyelet: Same Thing?

In home furnishings, “grommet” (US/Canada) and “eyelet” (UK/Australia) refer to the same thing: a metal ring punched through the curtain heading that slides directly onto a curtain pole. In this article, the terms are used interchangeably.

Grommet Curtain Fullness: Why 1.5–2× (Not More)

Most heading styles can be made with a range of fullness. Grommet curtains are slightly different: the fullness is partially constrained by the grommet spacing.

Grommets are spaced at fixed intervals along the top of the panel. The fabric between grommets forms a fold that hangs forward, then back, alternating. The depth of these folds is set by the grommet spacing and the fullness ratio.

Standard fullness for grommet curtains: 1.5–2×

Using more than 2× fullness on grommet curtains produces overly deep, awkward folds and puts stress on the grommet holes. Most curtain manufacturers use 1.5–1.75×.

Grommet Spacing and Fabric Width

Standard Grommet Spacing

There must always be an odd number of grommets on each panel — this ensures the first and last folds go the same direction (both forward or both back), giving the panel a symmetrical look.

Grommet Size

Grommet inner diameter must be at least ½” larger than the pole diameter:

• ¾” pole → minimum ¾” inner diameter grommet (1.25” outer is typical)
• 1” pole → minimum 1.5” inner diameter grommet
• 1¼” pole → minimum 1.5”–1.75” inner diameter grommet
• 2” decorative pole → minimum 2.25” inner diameter grommet

Step-by-Step Fabric Calculation

Step 1: Cut Width Per Panel

Finished panel width = pole width ÷ number of panels
Cut width per panel  = finished width × 1.75 (standard grommet fullness) + side hems

Side hems for grommet curtains: 1.5” per side (3” total) — same as other headings.

Example: 80” pole, 2 panels, 1.75× fullness:

Finished panel width = 80 ÷ 2 = 40"
Cut width per panel  = 40 × 1.75 + 3 = 73"

Step 2: Fabric Widths Per Panel

Widths per panel = ⌈ cut width ÷ fabric bolt width ⌉

Example: 73” cut width on 54” fabric:

⌈ 73 ÷ 54 ⌉ = ⌈ 1.35 ⌉ = 2 widths per panel

On 60” fabric:

⌈ 73 ÷ 60 ⌉ = ⌈ 1.22 ⌉ = 2 widths per panel

Step 3: Cut Length

Cut length = drop + top hem + bottom hem

Standard grommet hem allowances:

• Top hem: 4” (double-fold). The grommets are set into this folded hem for reinforcement.
• Bottom hem: 6” (double-fold, or weighted hem)

Cut length = drop + 4 + 6 = drop + 10"

Note: Do NOT add a rod pocket allowance — grommet curtains go directly on the pole via rings, with no pocket.

Step 4: Total Fabric

Total widths    = widths per panel × panels × windows
Total yards     = (total widths × cut length) ÷ 36

Full example: 80” pole, 2 panels, 1.75×, 84” drop, 54” fabric:

Cut width per panel = 40 × 1.75 + 3 = 73"
Widths per panel    = 2
Cut length          = 84 + 10 = 94"
Total widths        = 2 × 2 = 4
Total yards         = (4 × 94) ÷ 36 = 10.4 yards

Heading Tape Reinforcement

Grommet curtains need a stiff interfacing at the top to prevent the grommets from tearing through over time. Options:

Buckram is the professional standard. Purchase the same yardage as the total cut width of all panels combined:

Buckram needed = total cut widths × 4" / 12 = total cut width yards × (4/12)

For 4 widths of 54” fabric: 4 × 54" = 216" = 6 yards total cut width × (4/12) = 2 yards of 4" buckram.

Grommet Curtain Comparison vs Other Headings

Same window: 80” pole, 2 panels, 84” drop, 54” fabric:

Interesting: on an 80” pole with 54” fabric, all these headings need the same number of fabric widths (2 per panel) — so the fabric yardage is essentially the same. The fullness only “costs extra” when the cut width pushes you into the next bracket of widths per panel. See Curtain Fabric Yardage Formula for the full widths-per-panel calculation, and Eyelet vs Pencil Pleat Curtains for a window-by-window comparison.

Use the Curtain Fabric Calculator — select “Eyelet / Grommet” for automatic grommet curtain fabric calculation.

See also: Eyelet vs Pencil Pleat Curtains and Curtain Heading Types Guide.