How to Cut 90-Degree Outside Corners on a Miter Saw

Position the first piece of baseboard against the wall at the corner of the room so that the end sticks out 1 inch. Mark the board along its back where the corner meets the board.

Pull or twist the powered miter saw's locking handle and move it so that it rests on the 45-degree setting to the right of the central 90-degree setting. Lock the handle in place. Position the baseboard on the miter saw's base with the back of the baseboard vertical against the saw's backstop. Make sure the pencil line on the back of the baseboard is positioned directly under the saw's blade. Turn on the saw and slowly lower the blade to cut through the baseboard.

Position the second piece of baseboard against the other wall by the corner, so that the end of the baseboard sticks out 1 inch. Again, mark the board along its back where the corner meets the board.

Pull or twist the locking handle on the miter saw and move it to the 45-degree setting to the left of the central 90-degree setting. Lock the handle in place. Position the baseboard vertically on the saw's base with the back of the baseboard against the saw's backstop. Make sure the penciled line on the baseboard is directly under the saw blade. Turn on the saw and lower the blade to cut through the baseboard at the penciled line.

Position the two pieces of baseboard against the outside corner walls so that the two 45-degree cuts form a 90-degree outside angle.