A miter saw (also called a mitre saw and less frequently a miter box) is a tool used to make accurate crosscuts and miters in a workpiece.

Manual Miter Saw

The first miter saw ever made was the manual miter saw. It is a saw with replaceable blades suspended on rollers in a metal guide that allows making accurate crosscuts and miter cuts. They are used in picture framing but have largely been displaced by the power tool in carpentry and joinery operations.

Motorized miter saw

A motorized miter saw (also called a chop saw or drop saw) is a power tool used to make a quick, accurate crosscut in a workpiece. Common uses include framing operations and the cutting of molding. Most miter saws are relatively small and portable, with common blade sizes ranging from eight to 12 inches.

The miter saw makes cuts by pulling a spinning circular saw blade down onto a workpiece in a short, controlled motion. The workpiece is typically held against a fence, which provides a precise cutting angle between the blade and the longest workpiece edge. In standard position, this angle is fixed at 90°.

A primary distinguishing feature of the miter saw is the miter index that allows the angle of the blade to be changed relative to the fence. While most miter saws enable precise one-degree incremental changes to the miter index, many also provide "stops" that allow the miter index to be quickly set to common angles (such as 15°, 30°, or 45°).