How to Measure for Replacement Windows

How to Measure for Replacement Windows

If you need to replace your windows, one of the first steps is measuring. It can be difficult to know exactly how to do this correctly. It’s important to measure properly so the replacement goes well. Incorrect measurements can cause a list of issues. EnerPro Window Replacement of Denver, which does window replacement in Denver, has detailed everything you need to know about measuring for replacement windows.

Tips for Measuring Windows for Replacement

  • Measure from inside your home.
  • Make sure you are accurate for the best results. This will save you a lot of trouble later on.
  • Take your time so you truly get the correct measurement.
  • Double or triple check your measurements before placing an order.
  • Measure every window in your home. They may look like they are the same size, but they can vary slightly. It’s important to be accurate.

If you don’t measure properly, you will likely run into some problems. The main problem is that you may end up with the wrong size windows for the job. This can cost a lot of money. Then, you will have to measure again and place a new order. This alone is a good reason to measure correctly the first time.

What Supplies Do You Need to Measure for Replacement Windows?

Before you measure for replacement windows, make sure you have the needed supplies. You don’t need a lot in order to get the measurements. All you need is a measuring tape and somewhere to write down the measurements. It is a good idea to store this somewhere safe. Then, you won’t have to remeasure.

If possible, you can ask a friend or family member to verify that you’re measuring correctly. Having another person look at the measurements can help with precision. This isn’t necessary, but can give you some peace of mind. You will be able to catch any mistakes before ordering your new windows.

Understanding the Rough Opening and the Jamb

One part of measuring your windows includes the rough opening. Before you get started, you should know what this means.

According to Weather Shield, the rough opening is the framed opening of the window. In short, the window size you order must be smaller than the opening. This will ensure that it fits. The trimmers and headers around the window take up space too. This is why the rough opening is so important.

Another important term is the jamb. This is essential as you measure your windows. The jamb is the vertical frame around the glass windows. This is on each side of the window.

How to Measure a Window’s Width, Height and Depth

You should start by measuring the width of the window, from the jamb on one side to the jamb on the other side. Make sure you are measuring the inside of the window. You should do this at three different points of the window. For example, measure the top, middle and bottom. According to Pella, you should only record the smallest width measured.

To measure the height of the window, you should measure from the top frame of the window down to the windowsill. Again, you should measure in three spots, including the left, middle and right. Then, record the shortest height measured.

To measure depth, you will measure the stops that extend beyond the glass. Measure the shortest point of depth. This doesn’t have to be as precise as the other measurements. You only need a minimum depth in order to install the windows.

Do You Need Custom Windows?

According to Bob Vila, it’s best to order custom windows. This will ensure that they truly fit. Windows that are premade may be close, but they won’t be perfect. Order based on your measurements for the best fit. This will save you time and energy.

Why Might You Hire a Professional to Replace Your Windows?

It can be stressful to replace your windows on your own. Plus, a professional has the expertise to ensure the measurements are taken correctly. If you measure incorrectly, you will have to replace the order yourself. If a professional measures incorrectly, they will be responsible for the replacement.

If you aren’t into do-it-yourself projects, it can be convenient to have someone else handle this for you. They will have the needed tools and experience to ensure it goes well. This final decision is up to you though. Make the choice based on your needs and abilities.


Measuring your own windows for window replacements isn’t too challenging. Follow the guidelines above to get the closest measurements possible. You want to make sure you do it correctly so you don’t have to reorder your windows. Make sure you are as precise as possible. If needed, hire an experienced professional to help this go more smoothly.