When fit together, these corners make 90-degree angles.

General-purpose construction blades are too coarse to produce the very smooth cuts you want when fitting trim joints.

Power miter saws are now so affordable that any DIYercanown one, and so versatile that all DIYersshouldhave one.

blue wall and white baseboard

Valeriy_G / Getty Images

Another exceedingly useful tool is apower brad nailer.

Like power miter saws, brad nailers are extremely versatile and will quickly pay back your investment.

This is a very dangerous practice.

Materials and tools to fit baseboards with mitered inside corners

The Spruce / Hilary Allison

Need more help?

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.

Mark Cut Direction on First Baseboard

Lee Wallender

You may need to support the end of the baseboard so it rests flush against the table.

Wear eye protection and hearing protectors when cutting with a power miter saw.

Power up the saw, then lever the spinning blade down through the baseboard using a smooth motion.

Set Saw Before Cutting First Baseboard

Lee Wallender

check that you are tightly gripping the baseboard with your free hand.

Or, lightly scrape the edge with the blade of a utility knife.

This will allow you to cut the adjoining piece of baseboard.

Cut the First Baseboard

Lee Wallender

Cut the Adjoining Baseboard

Mark and cut the adjoining piece of baseboard, using the same technique.

Again, clean-up splinters or plastic burrs from the edges of the cut once the baseboard cools down.

Test-Fit the Baseboards

Position the baseboards in place to test the fit.

Remove Melted Plastic from Baseboard

Lee Wallender

The miter joint should fit tightly together with no appreciable gap between pieces.

Usually, you might get by cutting one adjusted piece rather than both baseboards.

Studs usually run every 16 inches on-center.

Set Saw Before Cutting Second Baseboard

Lee Wallender

You won’t need to locate studs in corners, as studs are always found there.

If necessary, adjust the tool to change the penetration of the brads.

Miter Saw and Radial Arm Saw Safety and Practice.

Cut the Second Baseboard

Lee Wallender

Massachusetts College of Art and Design.

Measure Your 90 Degree Cuts on Site

Lee Wallender

Baseboards Fit Together

Lee Wallender

Mark Location of Wall Studs

Lee Wallender

Nail Baseboards in Place

Lee Wallender