Accurate measurements are the difference between curtains that hang beautifully and curtains that never quite look right. This guide covers everything you need, and it takes about ten minutes per window.
A steel tape measure (fabric tapes stretch and will give you a false reading), a pencil and paper, a step ladder for tall windows, and ideally a second person for anything wider than about two metres.
Measure the width of the window recess at the top. Write it down. This is your reference figure, not the pole length.
The three measurements you need:
Your pole should extend beyond the window on both sides. This is the overhang, and it lets the curtains stack against the wall when open rather than covering the glass — letting in more daylight and making the window look larger.
Allow 15–20cm of overhang on each side. A 140cm recess therefore suits a pole of roughly 170–180cm.
Adjust for two things. Heavy or interlined curtains stack deeper, so allow up to 25cm each side. And if a wall, radiator or door frame restricts the space, work with what you have — but keep both sides equal, because an uneven overhang is far more noticeable than a modest one.
Allow 15–20cm of overhang each side so open curtains stack clear of the glass.
Fit the pole 10–15cm above the top of the recess. Higher draws the eye upward and makes ceilings feel taller.
Before you commit, check two things: that there is solid wall or timber to fix into above the window, and that the brackets will clear any window opening mechanism, blind fitting or coving.
Measure from the eye of the curtain ring—not from the pole itself—down to where you want the curtains to finish. Measuring from the pole is the most common error and gives curtains 3–4cm too long.
Choose your finish point:
Measure from the eye of the ring. For eyelet curtains, measure from the top of the pole instead.
Diameter is about weight and proportion, not just appearance.
Poles over about 200cm need a centre bracket. Over 300cm, use two. If the curtains must draw the full width, specify passing brackets so the rings glide over the support.
Diameter is about weight and proportion, not just appearance.
Poles over about 200cm need a centre bracket. Over 300cm, use two. If the curtains must draw the full width, specify passing brackets so the rings glide over the support.
Bays need more care. Measure each face separately along the line the pole will actually sit on—not at sill level, since in a splayed bay these differ. Record every corner angle individually with an angle finder; corners in older houses are frequently unequal.
Our bay window fitting guide covers this in full, and the five mistakes to avoid list the errors we see most often.
Measure every window individually, even in a room where they look identical — a 2cm difference is common in older properties.
If your curtains already exist, measure them before ordering the pole rather than the other way round.
Remember finials sit beyond the pole ends. A pole described as 180cm may occupy 195cm of wall once finials are fitted. If space is tight, check the total fitted width.
Browse Curtain Poles or Curtain Tracks.
Deep recesses, bays, sloping ceilings and windows close to a corner are all worth checking before you order. Send us your measurements and a photograph and we will confirm what will work.
