How to Measure for Replacement Windows

By installing replacement windows yourself, you can save a sizeable sum of money.  However, if you do not have the knowhow, or the time, or the experience working with tools, then you may want to hire a contractor to install your windows for you.  If you are a good do-it-yourselfer, then the following instructions will guide you on how to properly measure for replacement windows.

FACT:  Window dimensions are always given as width x height. 

When measuring for windows, make sure that you use a metal tape measure and not a cloth tape measure.  Measure across the top of the window from the inside of the window frame where the window opens, measure from the top right corner to the top left corner to the nearest 1/16 of an inch.  Measure across the width of the window at the midway point, and then measure the bottom portion of the window. 

All three measurements should be the same.  If they are not, then use the smallest measurement.  Once you have your measurement, subtract ¼ of an inch from the measurement, this is the correct width for your new window.  It is important to note also that you have to measure every window you are planning to replace.

When measuring the height of the window, make sure that you measure at the highest point of the windowsill as most exterior windowsills slope downward from the widow to allow water to drain away from the house.  You will need to measure the height of the windows, by taking measurements from the top right-hand side of the window, c center of the window and the left side of the window, taking the smallest measurement of the three.  Again, you will use a metal tape measure; place the tape at the top where the upper sash closes, and measure down to the highest point of the sloped sill, then deduct 3/16 of an inch to obtain the correct the height for your new windows.