Electrician’s Conduit Hole Saw Sizes Guide

1/2″ Trade Size conduit, drill using a 7/8″ hole saw or 1/2″ conduit knockout punch (.885″ or 22.5mm).

3/4″ Trade Size conduit, drill using a 1 1/8″ hole saw or 3/4″ conduit knockout punch (1.115″ or 28.3mm).

1″ Trade Size conduit, drill using a 1 3/8″ hole saw or 1″ conduit knockout punch (1.362″ or 34.6mm).

1 1/4″ Trade Size conduit, drill using a 1 3/4″ hole saw or 1 1/4″ conduit knockout punch (1.701″ or 43.2mm).

1 1/2″ Trade Size conduit, drill using a 2″ hole saw or 1 1/2″ conduit knockout punch (1.951″ or 49.6mm).

2″ Trade Size conduit, drill using a 2 1/2″ hole saw or 2″ conduit knockout punch (2.416″ or 61.5mm).

2 1/2″ Trade Size conduit, drill using a 3″ hole saw or 2 1/2″ conduit knockout punch (2.914″ or 74mm).

3″ Trade Size conduit, drill using a 3 5/8″ hole saw or 3″ conduit knockout punch (3.539″ or 89.9mm).

3 1/2″ Trade Size conduit, drill using a 4 1/8″ hole saw or 3 1/2″ conduit knockout punch (4.044″ or 102.7mm).

4″ Trade Size conduit, drill using a 4 1/2″ hole saw or 4″ conduit knockout punch (4.544″ or 115.4mm).

Additional Helpful Info May be Viewed at 

NEMA Knockout Info 

Rigid and EMT Size Chart