It depends on where you order them, different companies have different policies and they will tell you what they are. Usually you take two measurements, top and bottom, from the inside of one side of the window to the other side.
All purpose Coolaroo roll up window shades come in size 8' X 6', 4' X 6'
The best way to measure windows for blinds and shades is to use a measuring tape. Using a measuring tape will allow the individual to extend the tape until it can be measured.
To roll up shades neatly, start by raising it fully and then lower it halfway. Next, make sure the fabric is straight and even before rolling it up tightly from the bottom. Finally, secure the rolled shade in place with any provided hooks or ties.
The Roll-On Window Shade for cars do.
To install cellular shades in your home, start by measuring the window opening. Then, mount the brackets at the top of the window frame and slide the shades into place. Secure the shades by tightening the screws on the brackets. Finally, test the shades to ensure they operate smoothly.
To install cellular shades in your home, start by measuring the window dimensions. Next, mount the brackets provided with the shades inside the window frame or on the wall. Then, insert the shades into the brackets and secure them in place. Finally, test the shades to ensure they operate smoothly.
tape measure
Some good room darkening shades would be Redi Shades. They have black out blinds in many styles and colors. You can also make your own black out shades by adding dark felt to the back of your curtains or a roll down shade.
This site offers detailed, step-by-step instructions for measuring for Roman shades. It gives instructions for both regular Roman shades as well as Fusion shades: http://www.selectblinds.com/romanshades/measure-roman-shades.aspx
Unlike normal curtains or blinds, roman window shades have several segments of fabric that roll down over the window. Here's a picture: http://www.shadesshuttersblinds.com/images/roman-shades-image-3.jpg
Coolaroo Classic Series , window shades are made from coolaroo knitted fabric
Roll up blinds, or shades, are definitely outdated and somewhat tacky. For about the same price you can now purchase plain blinds that give a bit more of a modern look. They are fashionable and functional.