One of the first steps in ordering replacement windows for your home is to make sure the new units will be a proper fit. The measurements must be accurate, otherwise, you will have to order new windows. Knowing how to measure for window replacement in the correct way will save you a lot of time and hassle.

We have prepared a guide for you on the best way to measure your windows Barrie. Follow these steps and you will be able to order the correct size windows for your replacement project.

How to Measure Windows for Replacement

One of the best tips we can give you for measuring for your replacement windows Barrie is to measure twice to ensure that the measures are correct. If you do not record the precise measurements, the new unit will not fit and you will have to reorder the correct size windows. Take the width of the tape measure into consideration when recording your calculations. 


  • Tape Measure
  • Slide Rule
  • Pen or Pencil & Paper
  • Ladder or Step Ladder



Obtain an accurate measure of the width of the window using your tape measure or slide rule. Always measure the width from the middle of the unit as well as the bottom and top. Be sure to accurately record each measurement as soon as you take it so you do not inadvertently mix up the numbers in your head. To avoid inaccuracy, measure from the window jamb and frame and not the extension. 


The next step is to measure the lining of the window. If you are not able to obtain this measurement, as you cannot safely reach it, you can use the industry-standard one (½ inch). The lining is usually made of plastic or aluminum and is needed for installing the window jamb on the vertical side of the window. 


In order to obtain accurate measurements of the window height, you will have to measure from the left side first, followed by the middle, and lastly the right side. For vaulted windows, you will need to measure from the highest point of the window to get an accurate reading. 


This is perhaps the most crucial measurement. If you do not record this measurement correctly, you will have to reorder your windows, as they will not fit properly. As always, measure at least twice to ascertain the correct numbers. You will need to measure the depth between the stops in the window frame on the front.

Pro Tip: How to Cut a Rough Opening for Replacement Windows

Now that you have mastered how to measure windows for replacement, why not cut the rough opening for the new unit? To do so, use the measurements that you have recorded above and determine the width, height, and depth you will need for the window material. Keep in mind that both the height and width must be two inches larger than the window to account for the space of the sides of the unit. 

Once you have determined this, you will build a window frame by installing a header and cripple studs. Install the studs both above and below the rough opening to hold down the weight of the home structure through the studs as opposed to the window glass. Both the cripple studs and header must be installed before you put in the window replacement.

If you are unsure of how to measure windows for replacement, call Total Home Barrie to schedule an appointment. We will send a member of our team out to obtain the correct measurements. Call us today to discuss your options for the most energy-efficient windows in Barrie and the surrounding area.