How to Measure Windows for Replacement

single picture window installation

If you are looking to replace your windows, then knowing how to measure windows for replacement is a must. Why? Without doing the proper research and measurements, you could end up ordering the wrong-sized windows that won’t fit your home, and they may not be square enough. Not only will this be a waste of time, but your money too, as most window manufacturers won’t take responsibility for receiving incorrect measurements. So, you need to be prepared and avoid this tough situation. To do so, continue reading to learn about the six steps on how to properly measure windows.

Step 1. Gather the tools and do your research

two line slider window

In order to be prepared for avoiding tough situations, it requires the proper tools and ample research. Don’t fret though, as we will pave the way and simplify these requirements for you. When looking at this list we are about to share, you may realize that you have these tools laying around in your garage, shed or laundry room. If so, great! If not, all you need to do is make a quick trip to your local hardware store and buy:

  • A measuring tape. This is the tool you will use to take measurements. Opt for a bright yellow one so that the numbers are easy to see.
  • A level. This tool will help you to see if your windows are straight and aligned.
  • A pencil. You can use this to write on paper to record measurements.
  • A notepad. This is where your measurements will be recorded, so keep it in a safe and visible place.

While these supplies may seem mundane, they will help you to record more accurate window measurements as well as keep a log, which can help you double-check all dimensions. It’s better to be safe than sorry.

Step 2. Measure window width.

triple glass window replacement

Once you have all the necessary supplies in place, the next step is to measure your window’s width. Remember the measuring tape, pencil, and paper we mentioned? It’s time to get those handy. Take note though that if you are working on an older home that contains vinyl windows, then a window sash may be needed.

To start measuring your window’s width, you might think you need to start at the wooden frames, but you actually need to start with the window jams. We recommend that you take at least three measurements and write them all down. Next, take the lowest number you have recorded and decrease it by 1/8 of an inch. The number you calculate will be your overall width measurement to take to the manufacturer.

Step 3. Measure window height.

window image

When you measure windows for replacement, you cannot stop at the width, as height is important too. To record this number, you will use a similar technique to that above, but there are some specific changes to note. This time, you will also need your level, on top of the other supplies. For this dimension, take your measuring tape and start at the top of the window.

You will then want to draw it out to the highest point of the windowsill. Since frames can become distorted due to moisture and humidity, finding the highest points is key.
Just like the width, look at the smallest number you have recorded and decrease it by 1/8 of an inch. Voila! You have your height measurement.

Step 4. Measure window depth.

image of a window design

You’re almost done collecting all the dimensions, but you cannot forget about depth! This is actually one of the most challenging measurements to collect because it is the most important. You want to ensure that your window will sit flush with the frame, otherwise, it could wobble and move forward. Imagine what a disaster that would be.

So, when it comes to depth, here is how to measure for new windows.
When using your tape measure, make sure that you are including the entire window opening. This includes collecting measurements of the inside and the outside. A good rule of thumb is that your measurement should be 3 ¼ inches or else the end result will be skewed.

Step 5. Look At The Room And Quantity

patio windows and doors

People often overlook this step, but they should not, as it is an essential part of knowing how to measure for windows. So, what does this entail? You need to survey the size of your room, the number of windows it includes and how many replacement windows you will need.

Make sure that you have all the measurements for every single window. We recommend labeling them with a permanent marker on duct tape so that you do not get them confused.

Step 6. Draw a rough sketch

white entrance door with top window

You don’t have to be Picasso to do this, we promise. However, drawing a rough sketch of all the windows in your house per room can benefit you with the end results.

Record all the individual measurements of the window frames too.

Something to note in your sketch too is if you would like to have windows that open up, or if you would like them to remain fixed.

Remember FOOO:

F: fixed
OL: open left
OR: open right
OU: opens and slides up
OD: opens and slides down

Contact Us

When it comes to window replacements, you are in good hands with Milano Windows & Doors. We are a 6-time award winner for HomeStars. Since 2017, we have served the GTA and surrounding areas with professional expertise and customer service. Surrounding areas include Toronto, Vaughan, Richmond Hill, Maple, New Market, Mississauga, and Brampton. Our services include window and door replacements.

For windows, there are endless options to choose from: casement windows, fixed, casement windows, awning windows, single slider windows, double slider windows, end vent slider windows, single hung windows, double hung windows, and even picture windows. Imagine a new entrance door, porch enclosure, or storm door. Let us make it happen for you!
Call us today at 905-597-2977 to get up to 40% of your window replacements until October 24, 2022.

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