Sill & below-sill curtains
The legacy guide used roughly 0.5–1 cm above the sill for a sill-length treatment and about 15 cm below the sill as a common below-sill option. Radiators and deep projecting sills can alter the best finish.
Curtain Guides & Advice
How to Measure Curtains
Getting the width and finished drop right is one of the most important parts of ordering made-to-measure curtains. The measurements you need depend on whether a pole or track is already fitted and on the curtain heading you choose.
This guide takes you through the process step by step, with illustrated examples for curtain poles, tracks, new installations, finished curtain lengths and bay windows.
How to Measure Curtains — Step-by-Step Video
We plan to add a practical measuring video here. It will show the same process as the illustrated guide below: pole or track width, finished drop, heading reference points and the checks to make before ordering.
Until then, the diagrams and written instructions below give you the complete measuring process.
Video guide coming soon
Follow the illustrated guide below for now.
Before You Start Measuring
Where possible, fit the curtain pole or track before taking the final made-to-measure dimensions. That gives you a definite width, fixing height and hanging point rather than relying on an estimated position.
- Use a rigid metal tape measure.
- Record measurements in centimetres.
- Measure every window individually.
- Decide whether you are using a pole or a track.
- Choose the heading before confirming the finished drop.
- Check handles, sills, radiators, switches and sockets.
- Think about where the curtains will stack when open.
- Take every important measurement twice.
Give the maker the finished width — not your own fabric calculation.
For made-to-measure curtains, the curtain maker calculates fullness and fabric quantity from the pole or track width, heading, fabric and pattern repeat. You do not need to multiply the width yourself.
Planning the Curtain Pole or Track Position
If the pole or track has not yet been fitted, its position affects both the overall width and the finished curtain drop. The previous guide used around 10–15 cm above the window recess and around 15–20 cm beyond each side as useful starting points.
Those are planning figures rather than universal rules. Fuller or interlined curtains can need more wall space to stack back, while radiators, switches, furniture and the construction of the wall may change the practical position.
Step 1: Measure the Curtain Width
If the pole or track is already fitted
Measure the hardware rather than the glass. For a curtain pole, use the working pole width excluding the decorative finials. For a curtain track, measure the usable track length from end to end.
If your track includes specialist returns, overlaps or a bay configuration, record those separately rather than trying to reduce everything to one straight measurement.
If the pole or track has not been fitted
Measure the width of the window opening or architrave, then add the amount you want the new pole or track to extend beyond each side. That extra width gives the curtains room to overlap the opening and stack back when drawn.
Do not include decorative pole finials in the curtain width.
The useful measurement is the working width the curtains travel across, not the decorative ornaments at the ends of the pole.
Step 2: Choose the Finished Curtain Length
Before measuring the vertical drop, decide where the finished curtains should end. The most common treatments are sill length, below sill, floor length and a deliberately pooled finish.
Floor & pooled curtains
A tailored floor-length curtain is commonly specified just clear of the floor. A pooled treatment deliberately adds extra fabric to the drop and should be agreed as a design choice before making.
Step 3: Measure the Curtain Drop
The correct starting point depends on the curtain heading and the hardware. This is why it is best to choose the heading before taking the final finished drop.
Measuring the drop from a curtain pole
For pencil pleat and pinch pleat curtains hanging from pole rings, measure from the eye of the curtain ring to the chosen finished end point. For eyelet or tab-top curtains, measure from the top of the pole.
Measuring the drop from a curtain track
For a track, measure from the glider or hook point that actually supports the curtain down to the chosen finished length. Track systems vary, so use the real hanging point rather than simply measuring from the ceiling or top edge of the track.
Wave and specialist headings need the correct track system.
If you are ordering Wave curtains or another heading tied to a particular track, confirm the measuring point for that exact system before placing the final order.
Measuring When There Is No Pole or Track Yet
You can take provisional measurements before the hardware is installed, which is useful when you want an initial quotation or are planning the treatment at the same time as the track or pole.
Measure from the proposed fixing height down to the desired finished end point. The previous guide commonly allowed around 10–15 cm above the recess when planning the fixing position.
Remeasure once the hardware is fitted for a precise floor or sill finish.
Provisional measurements are suitable for planning and quoting, but if the curtains must finish exactly above a floor, sill or radiator, take the final drop from the installed pole or track.
Measuring Bay Windows & Checking Obstructions
Bay windows should not normally be treated as a single straight width. Record each straight section separately, including the angled sections and any returns, so the track or pole geometry is clear.
Check window handles, projecting sills, radiators and valves, switches, sockets, nearby furniture and the amount of clear wall or bay space available when the curtains are fully open.
Complex, curved or unusually angled bays are a good candidate for professional track specification or installation before final curtain measurements are confirmed.
Common Curtain Measuring Mistakes
- Measuring the window instead of the fitted pole or track. Once the hardware is installed, its usable width is normally the relevant finished curtain width.
- Including decorative finials. Finials sit outside the working width of a curtain pole.
- Not allowing enough stack-back space. This can leave too much curtain covering the glass when the curtains are open.
- Measuring from the wrong point for the heading. A ring eye, pole top and track glider are different reference points.
- Leaving the heading decision until after measuring. Choose the heading first so the hanging method and measuring point are known.
- Ignoring uneven floors. Check more than one vertical position where a floor or ceiling may not be level.
- Forgetting radiators, sills or window handles. These can change both the finished length and how the curtains operate.
- Treating an estimated pre-installation measurement as final. Confirm dimensions after hardware installation when the finish needs to be exact.
Quick Curtain Measuring Checklist
- Measure the pole width excluding finials, or the usable track width.
- If no hardware exists, measure the window opening and plan side extensions.
- Choose the curtain heading.
- Choose sill, below-sill, floor or pooled finished length.
- Measure the drop from the correct ring, pole or track point.
- Record returns, overlaps or separate bay sections.
- Record all obstructions and stack-back restrictions.
- Double-check the final measurements before ordering.
How to Measure Curtains FAQs
Should I measure the window or the curtain pole?
If a pole or track is already fitted, measure the usable hardware width. Measure the window itself when you are planning new hardware and need to establish the proposed overall width.
Do I include curtain pole finials in the width?
No. Measure the working pole width between the decorative finials rather than the full decorative end-to-end dimension.
Where do I start measuring the curtain drop?
It depends on the heading and hardware. Pleated curtains on pole rings are commonly measured from the ring eye, eyelet and tab-top curtains from the pole, and track-hung curtains from the relevant glider or hook point.
Should the pole or track be installed before I measure?
Where possible, yes. You can measure provisionally before installation for planning or a quotation, but the installed hardware gives the most reliable final width and drop.
How far should a curtain pole extend beyond the window?
About 15–20 cm each side is a useful broad starting point from the previous guide, but the right amount depends on window size, curtain fullness, fabric, heading and available wall space.
How high above the window should the pole or track be?
About 10–15 cm above the recess is a common planning starting point, but bracket requirements, wall construction, room proportions and the chosen curtain design may suggest a different position.
Can I measure a bay window myself?
You can record each straight section and obstruction for an initial discussion or quotation. For complex curved or angled hardware, it is sensible to confirm the final track or pole specification before the curtains are made.
Related Curtain Guides
Ready to Order Made-to-Measure Curtains?
Once you know the pole or track width, finished drop and preferred heading, you have the key measurements needed to start specifying your curtains.
