Cutting Angles Right the First Time

Mark Direction of Cut on First Baseboard

Press the squared-off end of the first baseboard piece tight into the corner along the floor. It doesn't matter if you begin with the left or right side; in our example, the first piece is on the right side. Use a pencil to make a direction line on the top of the baseboard, marking at a roughly 45-degree angle from the inner corner outward toward the face of the baseboard. This will help you orient the piece of trim on the miter saw before you cut it. It's surprisingly easy to get the direction wrong when you are cutting many pieces of trim.

Set the Saw Angle

Move the miter saw's blade to an angle just slightly less than 45 degrees to the back fence. While it might seem as though 45 degrees is the perfect angle to achieve 90-degree corners, just a fraction of a hair less than 45 degrees (but no less than 44 degrees) produces a better fit when you fit the two adjoining pieces of baseboard. This is because room wall surfaces usually are slightly rounded off where they meet in the corners, falling short of being perfectly square.