Abstract: An oval mat cutter allows the continuous adjustment of the overall size of the oval as well as the difference between its larger and smaller axes. The cutter may also produce circles. The cutter separates the knife from a first point which it keeps in a first groove. It separates this first point from a second point which it keeps in a second groove lying perpendicular to the first. A generally circular motion of the cutter while maintaining the two points in their respective grooves creates the desired oval. Making the two points in their respective groove coincide with each other will result in the production of a circle. The knife that makes the actual cut sits next to a wheel whose outer circumference has a sharp ridge. The knife has configurations where it extends to various distances beyond the edge of the wheel and one in which it sits within the wheel's circumference. To make a clean cut, the wheel, with the knife retracted, makes a groove in the mat.