How to Cut a 45-Degree Angle With a Compound Miter Saw

Updated February 21, 2017

A compound mitre saw is a woodworking tool used to cut pieces of wood at an angle. It can perform many functions but is most frequently used to cut the corner pieces of crown moulding and trim. While a traditional mitre saw cuts wood at a vertical angle, a compound mitre saw also makes the cut at a horizontal angle or slant. The 45-degree angle is the most basic and most often used cut.

Attach the compound mitre saw to a work bench as instructed by the saw's user manual. The saw must be completely steady and secure so that it does not wobble or shake during the cutting process.

Plug the electrical cord of the compound mitre saw into an electrical socket.

Grasp the handle at the lower front of the compound mitre saw and move it left or right until the top arrow is at the 45-degree mark. On some saws, you must turn the end of the handle counterclockwise to unlock it before sliding it.

Reach around to the back of the compound mitre saw and find a knob, or a bar with a knob at the end of it. Turn the knob counterclockwise until the saw tilts sideways. Look at the front of the saw where the angle marks are and tilt the saw either left or right until it lines up with the 45-degree angle mark. Turn the back knob clockwise to lock the blade in place.

Insert a piece of wood into the wood guide positioned just under the saw blade. Push the wood as far back as it will go.

Turn the compound mitre saw on.

Grasp the top handle of the mitre saw and slowly lower the blade until it cuts through the wood at a 45-degree angle.

Turn off the machine and allow the saw to come to a complete stop before raising the blade.


Wear ear plugs and safety glasses.

Things You'll Need

  • Work bench
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About the Author

Kimberly Johnson is a freelance writer whose articles have appeared in various online publications including eHow, Suite101 and Examiner. She has a degree in journalism from the University of Georgia and began writing professionally in 2001.