How to measure for replacement windows and patio doors

Getting a rough idea of your window measurements doesn’t take a lot of DIY home improvement skills. But before you buy, it’s a good idea to have a professional measure them before you begin a replacement project. Our project managers accurately measure and record the dimensions of your windows so they’ll fit perfectly when we install them. We verify the height, width, and depth of each window before sending your order to manufacturing.  

When you schedule a free design consultation with an Infinity consultant, they will inspect your windows to determine their condition. Our consultants also explore all the available options for your home and answer all your questions.  

• Tape measure 
  
  

• Pen or pencil 
  
  

• Measurement form 
  
  

• Ladder 

Project time: Less than two hours, about five minutes per window 

Sash: The operating and/or stationary portion of the window that holds the glass and is separate from the frame. 

Head jamb: The horizontal piece forming the top of the frame on a window or door. 

Sill: The lower, horizontal piece of a window or exterior door frame that supports the frame. 

Jamb: A jamb is the vertical side of a window frame.  

Window and door measurements are always recorded width first and then height.  

1. Measure window width 

For windows, measure the inside of one jamb to the other with a tape measure. The jamb is the vertical piece of trim on each side of a window. If your window doesn’t have a jamb, measure from each end of drywall. Record the measurement.  

Do not include the trim in your measurement. It’s a good idea to take three measurements and use the shortest measurement. Measure twice, cut once, right? 

2. Measure window height 

For windows, measure from the sill to the head jamb with a tape measure. If your window doesn’t have a head jamb, measure from the sill to the drywall. Write down the measurement. Take three measurements in three different locations to ensure accuracy. Use the shortest measurement.  

3. Measure window depth 

You don’t need to measure depth because an Infinity consultant will verify your measurements during your appointment. Window depth is tougher to measure because windows might not rest exactly at 90°.  

Measuring patio doors takes just a few steps.  

1. Measure patio door width 

For patio doors, measure from the inside of one jamb to the other with a tape measure from inside your home. Record the measurement.  

2. Measure patio door height 

For patio doors, measure from the threshold, to the head jamb with a tape measure from inside your home.  

The hidden complexities of patio door measurement

What seems like a simple patio door measurement can quickly become complicated. This can lead to common door measurement mistakes that DIY enthusiasts often run into:

• Structural considerations — Wall settling, foundation shifts, and previous installations can create irregular openings that aren't noticeable right away
  
  

• Threshold assessment — Evaluating deterioration, height variations, and drainage requirements all demand expert knowledge
  
  

• Operation clearances — Calculating proper clearances for different door types (sliding door versus French door measurements) requires understanding building codes and manufacturer specifications
  
  

• Multi-point measurement analysis — Professional measurement includes multiple points throughout the opening to identify irregularities
  
  

• Door measurement tips — Professionals know to account for seasonal expansion/contraction and material-specific requirements

Infinity’s experts are specially trained to handle these patio door measurements with ease and accuracy: 

Expert assessment process 

Your Infinity consultant will conduct a thorough evaluation that goes far beyond basic measurements: 

• Comprehensive opening evaluation — Examining not just dimensions but structural integrity 
  
  

• Performance analysis — Determining the best door configuration for your home 
  
  

• Design consultation — Helping you select the perfect style that complements your home's architecture 
  
  

• Technical verification — Ensuring all measurements account for installation requirements 
  
  

• Custom solution development — Creating a custom plan just for your project  

Standard and custom patio door options 

Infinity by Marvin offers flexibility to meet your specific requirements: 

• Standard patio door sizing — Our collection includes popular dimensions that fit many conventional openings 
  
  

• Custom solutions — We can create patio doors tailored to your exact specifications when standard sizes won't work, ensuring a perfect fit