Measure across top of door and on the inside and add 3 8 inch to the measurement.
Cut flooring trim at angles.
Just an fiy take on the same principal that chris uses there s a youtube video that shows a master carpenter who basically threw out his angle finder crown molding protractor in lieu of a roll of paper drywall joint tape to figure out angles a link is easy to find by typing how to measure for crown molding without tools but basically the idea is cut 2 strips of joint tape.
For the initial angle turn the base clockwise until the saw points to the 45 degree angle mark which you can see on the angle gauge beneath the base.
Cutting the trim for a door is another great way to practice with your miter cutting skills.
Cut the 45 degree angle on both sides from the short to short direction.
Slice a trim board at a 45 degree angle.
The video above provides a great cheat sheet that makes it even easier for you to identify exactly what angle you need to cut.
The most popular angles for interior trim are 90 and 135 degrees and each of those angles can be straight on or with a bullnose.
You will need a miter saw to cut the trim at an angle and form a corner.
If you need to measure a mitered angle that s other than 90 degrees you could hunt around for your protractor but there s a better way.
Miter saws have adjustable bases you set to the angle you wish to cut.
The first step in cutting trim is going to be identifying the angle you need to cut.
Record this measurement with an additional note detailing if the left and right sides of the trim are.
Measure along the wall and floor junction from the first corner to the first cut point.