A miter saw assembly comprising: a circular saw comprising: a circular blade, a motor operable to rotate the circular blade, a power supply operable to provide power to the motor, an attachment mechanism, a blade guard movable between an extended position covering the circular blade and a retracted position exposing the circular blade, and a blade guard lever operable to move the blade guard between the extended position and the retracted position, the blade guard lever movable between a closed position corresponding to the extended position of the blade guard and an open position corresponding to the retracted position of the blade guard; and a miter base comprising: a base, and a support arm comprising: a coupling arm detachably coupled with the attachment mechanism of the circular saw, a vertical pivot operable to pivot the coupling arm in a vertical plane, a horizontal pivot rotatably coupled with the base, the horizontal pivot operable to rotate the coupling arm in a horizontal plane, and characterised by a support arm lever rotatably coupled to the support arm, the support arm lever operable to rotate between an inward position and an outward position, wherein the support arm lever is operable to move the blade guard lever between the closed position and the open position as the support arm lever rotates between the inward position and the outward position. a circular blade, a motor operable to rotate the circular blade, a power supply operable to provide power to the motor, an attachment mechanism, a blade guard movable between an extended position covering the circular blade and a retracted position exposing the circular blade, and a blade guard lever operable to move the blade guard between the extended position and the retracted position, the blade guard lever movable between a closed position corresponding to the extended position of the blade guard and an open position corresponding to the retracted position of the blade guard; and a miter base comprising: a base, and a support arm comprising: a coupling arm detachably coupled with the attachment mechanism of the circular saw, a vertical pivot operable to pivot the coupling arm in a vertical plane, a horizontal pivot rotatably coupled with the base, the horizontal pivot operable to rotate the coupling arm in a horizontal plane, and characterised by a support arm lever rotatably coupled to the support arm, the support arm lever operable to rotate between an inward position and an outward position, wherein the support arm lever is operable to move the blade guard lever between the closed position and the open position as the support arm lever rotates between the inward position and the outward position. a base, and a support arm comprising: a coupling arm detachably coupled with the attachment mechanism of the circular saw, a vertical pivot operable to pivot the coupling arm in a vertical plane, a horizontal pivot rotatably coupled with the base, the horizontal pivot operable to rotate the coupling arm in a horizontal plane, and characterised by a support arm lever rotatably coupled to the support arm, the support arm lever operable to rotate between an inward position and an outward position, wherein the support arm lever is operable to move the blade guard lever between the closed position and the open position as the support arm lever rotates between the inward position and the outward position. a coupling arm detachably coupled with the attachment mechanism of the circular saw, a vertical pivot operable to pivot the coupling arm in a vertical plane, a horizontal pivot rotatably coupled with the base, the horizontal pivot operable to rotate the coupling arm in a horizontal plane, and characterised by a support arm lever rotatably coupled to the support arm, the support arm lever operable to rotate between an inward position and an outward position, wherein the support arm lever is operable to move the blade guard lever between the closed position and the open position as the support arm lever rotates between the inward position and the outward position.