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Tab Top Calculator — Tab Dimensions & Fabric
Calculate tab dimensions and fabric for tab-top curtains.
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
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.
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.
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.
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.
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Last updated: February 2026
All calculations are estimates. Always verify quantities before cutting or purchasing fabric.