How to calculate fabric quantities for curtains

Curtain fabric calculation, made simple for everyone to understand.

1. Choose a fabric and note the width and vertical pattern repeat
2. Measure the width of the pole or track you will be hanging the curtains on, from the far left hook or ring, to the far right one.
3. Measure the finished drop you require the curtains to be.
4. Take the pole/track width and multiply by 2 for pencil pleat, or 2.5 for pinch pleat heading. Divide this by  the fabric width to determine how many widths of fabric you will need to join up to give you sufficient fulness.
5. Now take the height measurement, add on 25cm for turning allowance, then divide by the pattern repeat measurement. Round this up to the nearest whole pattern repeat, and multiply by the pattern repeat measurement to give you the length to cut each drop so you can match the pattern. If the fabric states that the pattern repeat is a half drop match, an extra repeat needs adding on to each length. If the fabric is plain, then its just add 25cm.
6. Multiply the length of each drop by the total number of widths required, giving you the total amount of fabric required.
7. For the lining and interlining, the widths stay the same, but the cuts are calculated at the height plus 25cm.

An example of this calculation is as follows:

Curtain fabric width – 137cm

Curtain fabric pattern repeat – 63cm

Track width 270cm

Height 220cm

Chosen heading – Triple Pinch Pleat

270 x 2.5 = 675

675 / 137 = 4.92, rounded up to 5 widths,  requires 2 curtains 2.5 widths in each.

Height 220 + 25(turnings) = 245cm.  Divide this by the vertical pattern repeat of 63cm, gives 3.88 repeats, round up to 4 repeats, multiply by 63cm, totals 252cm cuts.

5 widths at 252cm = 12.60 Metres. This is the total fabric required.

Many curtain styles

Hints and tips.

When measuring for the track, make sure you allow enough each side to get the curtains off the window so as not block any light when the curtains are open.

Always round up on the width calculation, as curtains with not enough fulness don’t look good at all.

Roman Blind Calculations

This does depend on the detail of how you prefer to make the blinds, as ours have a large hem and a pelmet to cover the velcro stiutch lines at the top.

Based on our method, we require 40cm for turnings on the height. If the blind is 125cm wide or less, this can be made from a single standard width of 137cm.

If the blind is wider than 125cm, then a whole width is required for the middle, and a further width to add a join down each side. If there is a pattern repeat, you simply add 40cm to the height, divide this by the pattern repeat, and round up to the nearest whole repeat to calculate the length of cuts required to allow for pattern match.

We trust this is helpful.

Of course, we are more than happy to do all the calculations for you, and even make the curtains and blinds up and ship anywhere in the UK.