How to Cut Baseboard for a Rounded Corner

Hey-yo! I have been a busy little bee working on a fun project and will divulge all the small details tomorrow – but in the meantime we need to talk baseboard! A few weeks ago I told you that Spencer and I were working on some projects that had to be done “the right way” and were removing base and casing in our home… I even showed you the nice way to remove that base and casing!

And now… I am installing new baseboard and casing and even though installing base and casing is pretty easy and mostly self-explanatory installing base on a rounded corner may not be as simple.

One things for sure… Do NOT do it like this: End to End

Or like this: 45 degree Mitre

Those two options may seem like the way to go… and are much easier for sure, but they leave a huge gap between the base and the corner bead and they don’t flow around the corner.

Here is the right way!! The reason you are reading… You have rounded corners! Me too.

How to Cut Baseboard for a Rounded Corner

Tools Needed:

  • Pin Nailer
  • Air Compresser w/hose
  • 2" pin nails
  • Tape measure

How to Cut Base for a Rounded Corner (3) copy

The magic number for making beautiful corners is 22.5You want to make all cuts for rounded corners at a mitered 22.5 degree.

The very first thing I do is bust out my mitre box and cut my corner piece. It is about an inch long with a right 22.5 mitre and a left 22.5 mitre. I usually cut a few of these so I have them for all the corners in the room.

Holding a one inch piece right on the corner, I measure how long I need my pieces of baseboard. Then I cut them with the same 22.5 degree mitre.  I will test the pieces I cut to make sure everything fits and looks nice before I nail up the base.  Remember that the corner piece mitres go in and the baseboard piece mitres go out.

Remember when you are cutting your mitre, the measurement is from the back of the baseboard and not the mitre. If you cut from your mitre, your pieces will be too long. Make sense?

How to Cut Base for a Rounded Corner (8) copy

Now you are ready to insert and nail up your corner piece.

How to Cut Base for a Rounded Corner (13) copy

Sometimes as I go, I will cut one side, nail up the corner piece and then measure the next side. You can do it either way you feel most comfortable.

How to Cut Base for a Rounded Corner (15) copy

Then you can putty and caulk the small lines and holes, paint on a coat (which is what I was doing when I took this photo) fix anything you need too and put a final coat on.


I will touch this up and give it a final coat and you will see it again in an upcoming post! But now you know how to cut baseboard for your rounded corners!


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Hey there! We are Spencer and Amanda, a DIY husband and Wife team, sharing projects we build and create together for our home. Since buying our home in 2007 we have had the saying that Spencer builds it and makes it work and Amanda makes it look good. We hope you will stick around because we always have projects in the works!

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  1. Diana Byrd says:

    Thank you so much! I have had a horrible time trying to figure out, from a geometrical standpoint, how to get my baseboards to meet up at rounded corners! Talk about wasting time and money-I cut and wasted so many of my baseboards. Now I am set and ready to work again this next weeked!

    Thank you again!


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