Measure the cabinet opening, choose overlay or inset, and get the door or drawer-front size to order or build.
Start with the cabinet opening, then add overlay for overlay doors or subtract reveal for inset doors. Use the same logic for drawer fronts, but check the space around nearby fronts before ordering.
A 14 in wide by 26 in tall opening with 1/2 in overlay on all sides needs a 15 in by 27 in door.
A 30 in wide opening with 1/2 in overlay on both sides and a 1/8 in center gap needs two doors, each 15 7/16 in wide.
An 18 in by 24 in opening with a 1/16 in reveal on all sides needs a 17 7/8 in by 23 7/8 in door.
Measure the clear inside opening from left to right and from top to bottom. Write down each opening separately.
Overlay doors sit over the frame or cabinet side. Inset doors fit inside the opening and need an even reveal around the edge.
For paired doors, leave a small center gap so the two doors do not rub. This calculator subtracts that gap before splitting the width.
Drawer fronts use the same math, but nearby counters, doors, and other drawer fronts may limit how much overlay fits.
Old doors can be warped, trimmed, or made for different hinges. Measuring the opening gives a cleaner starting point.
If a pair of doors shares one opening, subtract the center gap before dividing by two.
Overlay is added to the opening. Inset reveal is subtracted from the opening.
A drawer front near a countertop or another front may need less overlay on one side.
Keep exact values while calculating, then round to the precision your shop or supplier accepts.
Save your usual overlay, reveal, center gap, and unit system before adding the next cabinet run.
End cabinets, drawer stacks, and doors near appliances may need a different left, right, top, or bottom value.
Replacement doors are often made to the size you submit. Recheck the opening and hinge overlay before ordering.