Whether you are planning on making curtains yourself, purchasing them from a store or ordering custom curtains, there is one piece of information that is vital to your purchase. This is the measurement of your window. Determining the width of curtains can be a tricky proposition. Though it may seem like common sense to simply measure the window and use this width, determining the correct width for curtains requires a few more steps.
Measure the width of your window at the top. Begin at the outer edge of one corner and extend your measuring tape to the opposite outer edge. If the window has trim, measure to the edge of the trim.
Add 3 inches for each side of the window to take into account the depth of rod brackets. This adds a total of 6 inches to your measurement in step 1.
Double the measurement you calculated in step 2. The extra material allows your curtains to hang in folds.
Record all of your measurements on a piece of paper to keep with you when shopping for curtains or for material for homemade curtains.
If you are using two curtain panels on a single window, their combined width should equal the final measurement you calculated in step 3. Do not purchase two panels that are each twice the width of the window; this will result in far too much fabric.
Make sure that all of your measurements are made in either inches or centimeters; do not mix the two.