Studio Matrx Monthly · Volume 1 · Issue 1 · June 2026
Amogh N P
 In loving memory of Amogh N P — Architect · Designer · Visionary 
Curtain Hardware Calculator

Curtain Rod & Track Length Calculator

Enter your window width and how far to extend each side — get the right rod or track length, the number of brackets / supports you need, and mounting tips. Extend wider than the glass so open curtains let the full window breathe.

Your window

15–25 cm is typical

Extension is the part of the rod that reaches past the glass so the curtains stack beside the window, not over it. For wide spans, heavy fabric or motorised curtains, a track is steadier than a rod.

Decorative rod length

0 cm

about 5.1 ft · width 120 cm + 18 cm each side

Brackets / supports

3

2 ends + 1 intermediate

Extension used

18 cm

each side, past the glass

Centre overlap

10 cm

panels cross at the middle

Mount height tip

Hang high

10–15 cm above the frame, or to the ceiling

Clearance from wall · Allow 5–7 cm projection so curtains hang clear of the sill, handles or a radiator.

Finial allowance · Decorative finials add roughly 16 cm beyond the brackets — buy the rod by its covering length, not the total with finials.

Overlap · A centre-open pair needs a ~10 cm overlap so the two panels meet with no light gap; cut each panel half the track width plus the overlap.

Worth knowing

Extend the rod or track wider than you think — when the curtains are open, they should sit beside the window and reveal the full glass, not bunch over it. For heavy, lined, blackout or motorised curtains, choose a track over a rod: it carries weight more smoothly and won't sag over a wide span.

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