Egress Window Calculator

This tool checks an emergency escape and rescue opening against the minimums in Section R310 of the International Residential Code. Enter the net clear opening width and height and the sill height above the floor, and it reports each of the four checks separately along with the dimension you would still need. A second tab works backwards from the one dimension you already know, and a third sizes a window well and says whether the depth calls for a ladder. The figures come from the 2021 IRC; the jurisdiction that adopted your code can amend them, so treat the result as a check rather than an approval.

Calculator Type
Measured In
The width of the hole when the window is opened normally, not the frame or the rough opening.
Measured to the bottom of the clear opening, not to the window stool.
The area each one has to make is the figure in the code. On the millimetre setting the square metre equivalent is shown first and the code figure named after it, because the square metre figure is a conversion rather than what the code says.
Widget
Measured In
The area each one has to make is the figure in the code. On the millimetre setting the square metre equivalent is shown first and the code figure named after it, because the square metre figure is a conversion rather than what the code says.
Widget
Measured In
Widget
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