The Standard Depth

• The standard depth range for a home window seat is 17 to 22 inches. This depth allows you to sit comfortably with throws and pillows around you.
  
  

Reasons to Make Your Seat Deeper

• Although the standard depth provides comfortable sitting, those who would like to use their window seat as a narrow day bed (for napping) will need a deeper seat. A 24-inch depth should suffice.
  
  

Bottom Line

• If you are planning to use your window seat primarily for sitting and decor, then the 17- to 22-inch depth will work will for you. If you plan on using your seat as a place to nap, then expanding that depth by a couple of inches will make the seat more comfortable.