How to calculate the amount of material you need for curtains
When you decide to sew the curtains you need for a room of your home or for every room, your first task is to choose the fabric. Once you do that, it is important that you purchase the correct amount of fabric so that you can complete each project without having to take the chance that you may not be able to get the extra amounts you need.
Before you visit the fabric store to purchase the curtain material, you must take the time to take the measurements of the windows for which you want to make curtains. Measure carefully and write down each measurement as you take it rather than relying on your memory.
Take two sets of measurements
For each pair of window curtains that you want to make, you need to take two sets of measurements. First measure the complete length of the curtain rod and then measure the length to which you want the curtains to extend down the window.
Take the measurement from the bottom of the curtain rod for this length. If you are making tab-top curtains, you will have to take the measurement from the bottom of the rings or hooks.
Allow for the fullness of the curtain
Curtains have more fabric in the width than they do in the length. The amount of fullness you want depends on the size of the window. There are several methods of determining the amount of fullness:
1. One and half times the width — This is the most economical option when buying fabric to make window curtains. Multiply the length of the curtain rod by 1.5 to determine how wide the curtain needs to be.
2. Twice fullness — This is an average size for the fullness of a window curtain. Multiply the length of the rod by 2.
3. Three times fullness — If you want a full designer look to your curtains, multiply the length of the rod by 3. This amount of fullness may be too overpowering for a small window or for a small room.
Calculate the fabric requirements for the width
The amount of fullness you decide on will tell you the total width of the fabric. Fabric also comes in specific widths, but for drapery material the norm is 60 inches. Divide the total width you want by 60 to give you the number of widths you will have to sew together. Round up to the nearest number.
Calculate the fabric requirements for the length
Measure the length you want for the curtains and add 10 inches to this measurement. This will give you the fabric you need for turnings for hems at the top and the bottom of the curtains.
Multiply the number you have for the length of the curtains to the number of widths to arrive at the proper amount of fabric that you need to buy.