Measuring up for your window treatments should be one of the first steps, and probably one of the most important, you make when it comes to windows. Get this wrong and no matter how good your curtains, the desired effect will not be achieved.
For curtains outside the recess the track or pole needs to be 4in - 6in (10cm -15cm ) wider than the window frame to allow for stacking the opened curtains. It should be fixed about 4in (10cm ) above the top of the window frame and should be horizontal.
It is advisable to make a plan of each window and transfer all the measurements onto it for future reference. Never presume that two windows are exactly the same size even if they look identical.
Take all the measurements in either inches or centimetres. Do not mix the two.
Measuring curtain width outside the window recess
Measure the width of the track or pole, adding any extra for centre overlapping, normally about 6in (15cm ).
Multiply the track width by 1.5, 2. or 2.5 depending on the heading to be used.
Divide that by the width of the fabric, normally 48in or 54in (122cm or 137cm ), and round up to the next whole number to give the number of widths required. If an odd number results then one width can be cut in half and added to the outside edge of each curtain.
Measuring curtain width inside the window recess
Measure the width of the window recess and multiply by 1.5, 2, or 2.5 depending on the heading to be used.
Divide that by the width of the fabric, and round up to the next whole number to give the number of widths required. If an odd number results then one width can be cut in half and added to the outside edge of each curtain.
Measuring curtain length outside the window recess
For a pole, measure from the bottom of the ring to wherever you wish the curtains to fall. For a track, measure from the top of the track to wherever you wish the curtain to fall. For tab top curtains, measure from the top of the pole to the required finished length. Deduct the length of the tabs (approx 3in or 7.5cm ) as the top of the curtain must come above the top of window frame. This may mean moving the pole.
To this measurement add 8in (20cm ) to the finished length — 2in (5cm ) for the top seam allowance and 6in (15cm ) for the bottom hem — for lined and unlined curtains with attached heading tape or tab tops.
For lined and unlined curtains with cased headings add 10in (25cm ) to the finished length — 4in (10cm ) for the top seam allowance and 6in (15cm ) for the bottom hem.
Short curtains should finish 0.5in (12mm ) above the sill or radiator and full length curtains should fall within 1in (2.5cm ) of the floor.
If patterned material is to be used then each length has to be a full pattern repeat. For example, with a pattern repeat of 25in and a curtain finished length of 54in you will need 75in for each drop, ie, 54in plus 8in for hems equals 62in rounded up to the next multiple of 25in (your pattern repeat ). Multiply this amount by the number of widths required and you have the length of fabric required.
To calculate the amount of lining required (if used ) multiply the finished length plus hem allowance by the number of widths required. Hem allowance is usually 6in (15cm ), 2in (5cm ) for the top seam and 4in (15cm ) for the bottom hem. Ignore any adjustments for pattern matching.
Measuring curtain length inside the window recess
Measure the length of the window recess. Curtains should finish 0.5in (12mm ) above the window sill so they fall correctly.
To this measurement add 8in (20cm ) to the finished length — 2in (5cm ) for the top seam allowance and 6in (15cm ) for the bottom hem — for lined and unlined curtains with attached heading tape or tab tops.
For lined and unlined curtains with cased headings, add 10in (25cm ) to the finished length — 4in (10cm ) for the top seam allowance and 6in (15cm ) for the bottom hem.
