What fullness ratio do tab top curtains need?

Tab top curtains use a lower fullness ratio of 1.5x. Because the tabs are fixed at intervals, too much fullness creates awkward bunching. The fabric hangs in soft folds between tabs.

How wide and spaced should tabs be?

Standard tab width is 4-6cm finished. Tab spacing (gap between tabs) is typically 10-20cm. Closer spacing gives a neater look; wider spacing creates deeper folds. The tab width plus spacing determines the drape pattern.

How long should curtain tabs be?

Tab length needs to loop over the pole. Measure the pole circumference (diameter x 3.14) and add 3-4cm for attaching to the curtain. A standard 28mm pole needs tabs about 13cm long.

Can I add buttons to tab tops?

Yes, buttoned tab tops allow easy removal for washing. Make the tab loop with one end folded under and a buttonhole, the other end with a button. This also adds a decorative detail.

SewCalcs

Tab Top Calculator — Tab Dimensions & Fabric

Calculate tab dimensions and fabric for tab-top curtains.

Pole Width

Pole length the pair spans, finial to finial

Finished Curtain Drop

Hanging length below the pole

Tab Width (finished)

Finished width of each tab, usually 4-6cm

Tab Spacing

Gap between tabs, typically 10-20cm

Pole Circumference

Diameter × 3.14 — a 28mm pole is ≈9cm

Fabric Width

Bolt width, e.g. 137cm

Fabric Price (optional)

Cost per metre of curtain fabric

How We Calculate This

Tab top curtains have fabric loops that slide onto the pole. Tabs are counted per panel — one at each end plus evenly spaced loops between — so a pair needs double that count.

The formula

Pair flat width = Pole width × 1.5 (tab-top fullness)

Per-panel flat width = Pair flat width ÷ 2

Tabs per curtain = ceil(Per-panel width ÷ (Tab width + Spacing)) + 1

Tabs for the pair = Tabs per curtain × 2

Tab loop = Pole circumference + 4cm

Tab cut: Width × 2 + 3cm, Length = Loop + 4cm (one folded strip per tab)

Frequently Asked Questions

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Last updated: February 2026

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