Measurement should be taken from the backside of the door, the side routed to accept a panel.

Pricing Example for a panel 12 3/8" x 24 13/16"
First round off size to next nearest full inch, 13" x 25".
Multiply 13 by 25 = 325, then divide 325 by 144 = 2.26
Multiply the square footage of item by the cost per square foot.
Example: 2.26 sq. ft. x $25.00 = $56.50

Glass should be ordered 1/8" to 1/4" less than the extreme routed opening, assuming the door is square.

Guaranteed sizing to plus or minus 1/16". If the routed area is wider than 7/16" you may want to adjust your glass sizing accordingly.  If the corners in the routed area
are radius corners please let us know.

one square foot = 144 sq.in.