How to Cut the Angles for Inside Corner Baseboard Molding

When trimming out a house, baseboards are used at the bottom of the wall to cover the joint between the sheetrock and the flooring material. A baseboard is a piece of trim molding, usually 3/4 or 5/8 inch thick, made from a solid piece of wood for staining, or from multiple pieces of wood for paint-grade moldings. The do-it-yourself handyman can determine the angles for the inside and outside corner cuts if he knows a few tricks of the trade.

Step 1

Measure from one corner to the next corner of the room for the dimension needed to cut the baseboard molding. Use a tape measure.

Step 2

Mark a piece of baseboard molding with this dimension. Use a pencil to mark the top edge of the molding.

Step 3

Cut the baseboard at 90 degrees to the face of the baseboard. Lower the sawblade slowly through out the cut to help prevent splintering of the wood.

Step 4

Nail the first piece of baseboard into place, using a pneumatic finish nail gun. Shoot the nails into the bottom plate to secure the baseboard.

Step 5

Adjust the miter saw to the 45-degree mark and lock it into place. Cut the end of the baseboard at 45 degrees.

Step 6

Back-cut the miter cut you just made on the baseboard with a coping saw. The saw is used to cut the profile at 45 degrees in the opposite direction. This leaves a knife edge of a profile that fits into the flat face of the other piece of baseboard, making a tight-fitting joint.

Step 7

Tap the end of the baseboard into the corner and mark the other end of the baseboard with a pencil for the next cut. Use a hammer for this step.

Step 8

Repeat steps 2 through 6 for the remaining inside corner baseboards cuts.


  • Wear safety glasses when using the miter saw.

About the Author

Jim Wildman served in the United States Marine Corps as a Communication Chief for 10 years. After his tour of duty in Desert Storm he attended Oklahoma State University receiving his Bachelor of Architecture. He worked as an architect for 10 years before starting his own design/build company. He began writing in 2009 for Demand Studios and published on eHow.