Instructions on How to Calculate Your Fabric Amounts for your Curtain

Instructions on How to Calculate Your Fabric Amounts for your Curtain

First, you should know that the key to the amount of fabric you need to buy to make your curtains is the design of curtain heading and the hanging method you choose.

Previously, you should know the type of curtain heading you want to achieve. And you've installed an appropriate track or pole system over your window. OK, now you're ready to measure up for the fabric quantity you need to purchase.

·  Measure the width of your curtain pole, track, or wire hanging system. Exclude the width of finials if using a decorative pole. But do include the width of the return brackets on your curtain track or pole if you have them.

·  Multiply this width by 1.5, 2 or 2.25 depending upon the amount of fullness required for your heading (see below).

Goblet pleat: multiply your width by 2.25 
Pierced heading: multiply your width by 1.5 
Smocked heading: multiply your width by 2 
Pinch (French) pleats: multiply your width by 2.25 
Rod pocket(slotted,cased,channelled): multiply your fabric width by 2.5 
Pencil pleat: multiply your width by 2.5 
Gathered: multiply your width by 2 

·  Divide this number by the width of your chosen fabric. (Standard fabric is normally 137cm (54") wide, but check when you buy). Round up to the nearest whole number. This is the number of widths of fabric required.

·  Measure the finished length of the curtains you require. If using a decorative pole, start measuring from the base of the ring from which the curtain will hang. If using a track, measure from 1cm above the top edge of the track so your curtain heading hides the track. If using a curtain wire system for pierced headings, measure from where the top of the curtain panels will be, remembering that you will make pierced holes in your fabric about 6cm from the top edge of the fabric.If making a rod pocket heading, measure from the bottom of your pole to the floor, then add 25cm for the stand-up frill and pocket you will create.

·  Add 10 cm to the top and 10 cm to the bottom of the length for hems in all cases. This gives you your cutting length.

·  Multiply the number of widths by the cutting length. This is the amount of fabric you need to buy.

If you are buying a fabric with a distinct pattern, you need to pattern match so that when the curtains are drawn together, the pattern matches up exactly on both inside edges where the curtains meet.

To allow enough fabric for pattern matching, add the following calculation:

·  Take the cutting length you have calculated. Add the length of the pattern repeat (the pattern repeat length should be stated on the label attached to the fabric roll in the shop).

·  Use this new, final cutting length and multiply by the number of widths. This is the amount of fabric you need to buy for fabric with a pattern repeat.

Here is an example of calculating the correct fabric amount required for a pair of curtains

The following gives an example of how to calculate the correct fabric amount for a pair of curtains.

Let's assume that I want to make curtains for a wide window and have attached a curtain pole above the window. The pole measures 240cm wide. I have decided I want a pinch (french) pleated heading and full length curtains that touch the floor. The distance between the bottom of the rings on the pole and the floor is 175cm. I have chosen a fabric with a distinct pattern repeat that measures 37cm, and therefore must ensure that I allow enough fabric for pattern matching.

·  Chosen heading: Pinch (French) pleats

·  Curtain pole width: 240cm

·  Finished length: 175cm

·  Pattern repeat: 37cm

Calculating number of widths

·  Width of curtain pole: 240cm

·  Multiply by 2.25 for pinch pleats: 540cm

·  Divide by fabric width of 137cm: 3.941

·  Round up to the nearest whole number: 4

The number of required widths of fabric is 4. 

How to calculate the length

·  Finish length of curtains: 175cm

·  Add hem allowance of 10cm to the top and 10cm to the bottom: 195cm

·  Add pattern repeat of 37cm: 232cm

·  Multiply the final cutting length of 232cm by our number of required widths which is 4: 928cm

I need to purchase 9.5 meters of fabric to make these curtains.

How to cut the fabric

·  As the total number of widths required is 4, that means each curtain will have 2 widths joined together.

·  Cut 4 lengths of fabric from your purchased roll, each length should measure 232cm long.Be certain to cut exactly straight across your fabric, at right angles to the length of your fabric. Marking your line with tailor's chalk and checking your measurements before you make the first cut is a good idea.

·  Your first job will be to join 2 fabric lengths together. Be sure to match up the pattern repeat at the join.See our instructions "Joining fabric panels"

·  Join the remaining 2 fabric lengths together, again matching the pattern. Trim any access fabric from the top and bottom of the lengths, so your length of each double curtain panel is 232cm.

·  Now you are ready to sew your curtains.