How to Calculate How Much Fabric to Buy. Whether it's curtains or a new tablecloth or perhaps a new spring dress, they all require fabric and notions to make them yourself. You don't want to buy too much or too little. Follow these guidelines to calculate how much fabric you will need.
Turn your pattern package to the back and review the printed chart. This will show you exactly how many yards you will need for that particular pattern.
Pick the fabric of choice and turn the fabric bolt to its end to read the width. Generally bolts will read 45" or 60" wide.
Using the calculation of the fabric width, read the number of yards recommended for the garment. Remember to go by the size of your pattern.
Selecting a striped fabric or one with patterns means you will need to allow extra yards for matching the designs in the fabric. If you altering the garment for height or sizing, factor in these calculations as well.
Measure the length of each pattern piece and add all of the measurements to calculate how much fabric to buy when you don't have the pattern guide to follow. Add in enough fabric for seams.
Ask the store salesperson for assistance if you want to double-check your calculations.