Architect,  Generic

How to make a miter cut

Here is some simple math if you have the right tool. Trying to miter two angles is not always the easiest task. Let me preface this with I would recommend a Jobber Calculator if you convert from feet-inches to pitches, degrees or other regularly. They are not paid advertising, just the tool I use regularly. If your a math person, you know how instrumental a Casio TI-84 was in school. There is probably a Texas Instruments app for this as well that I haven’t looked into. The other tool I use all day everyday is a piece of software shown below is Mitek engineering.

For this example I want to miter the 0 degree top chord to the 5/12 pitch top chord.

truss pitch

If you have a jobber builders construction calculator, enter the pitch as inches.

5 – 0 – PITCH

Then I convert to degrees with the DEG button. 22.6+ degrees.


Then we divide in half / 2 = 11.3 degrees is our miter cut as a degree


Then we can convert to tangent with the TAN key which is a .2 tangent


Then we can convert from tangent to feet – inches with the FIS button. 2 3/8 is out miter pitch.


There, now our joint has a more solid connection with a plate covering more area.

The metal plates have teeth which sink into the wood and is crimped. More teeth = more bite.

truss miter
Miter joint

Just another day in the life of the bumbling architect, I work with a firm in the building.

My name is Art Vandelay, I'm a truss designer or structural engineer which is like an architect. I follow the UNIX philosophy, do one thing and do it well. I have a few decades of experience working for large corporations maintaining high end servers for information services.