How many eyelets do I need per curtain?

Eyelets should be evenly spaced 12-18cm apart. Each curtain must have an even number of eyelets so the leading edge folds towards the window. This creates the signature wave fold of eyelet curtains.

What size eyelets should I use?

Eyelet rings are sized by their inner-hole diameter, which must be at least 10mm larger than the pole so the curtain slides freely. The two standard UK sizes are 40mm and 50mm: a 40mm ring suits a 28mm pole, and a 50mm ring suits a 35mm pole (a 66mm ring is also made for 50mm poles). Note that 28mm and 35mm refer to the pole diameter, not the eyelet.

How much heading fabric do I need above eyelets?

Allow 2-4cm of fabric above the eyelet ring for a stand-up heading. The heading folds over so you need double this plus the eyelet depth. This is included in the cut drop calculation.

Do I need eyelet tape or can I use loose eyelets?

You can use either. Eyelet tape (header tape with pre-spaced holes) is easier for beginners. Loose clip-together eyelets allow custom spacing. Both need a stiffened heading — use buckram or header tape interfacing.

SewCalcs

Eyelet Curtain Calculator — Eyelets & Fabric

Calculate eyelet spacing, heading fabric and ring quantities.

Pole Width

Pole length between the finials (the curtains gather across this)

Finished Drop

From top of eyelet ring to hem

Eyelet Inner Diameter

Ring inner hole: 4cm (40mm) for a 28mm pole, 5cm (50mm) for a 35mm pole

Eyelet Spacing

Centre-to-centre gap: 12-18cm gives an even wave fold

Heading Above Eyelet

Stand-up fabric above the ring, typically 3-4cm

Fabric Width

Bolt width: 137/140cm standard, 280cm for wide-width curtain fabric

Fabric Price (optional)

Cost per metre of your curtain fabric, for an optional total estimate

How We Calculate This

Eyelet curtains typically use 2× fullness (the standard for the eyelet heading), though 1.5× and 2.5× are selectable. The number of eyelets is calculated from the curtain width and spacing, always rounded to an even number so the leading and trailing edges both fold back towards the window.

The formula

Total width = Pole width × fullness (default 2× for eyelet)

Eyelets per curtain = round(Width per curtain ÷ Spacing) (rounded up to an even number)

Heading fold = (Above eyelet + Eyelet radius + 2cm) × 2

Cut drop = Curtain drop + Hem + Heading fold

If you enter a pattern repeat, the cut drop is rounded up to the next whole repeat so the motif lines up across each fabric width.

Frequently Asked Questions

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Last updated: February 2026

All calculations are estimates. Always verify quantities before cutting or purchasing fabric.