A surgical instrument includes an end effector supported on a distal end of an elongated shaft, a clamping rod, and a measurement mechanism. The clamping rod extends through the elongated shaft and is operatively associated with the end effector to transition the first and second jaw members between open and clamped positions. The measurement mechanism includes a cylinder, a biasing member, and a locking member. The biasing member is disposed within the cylinder and is disposed over a proximal end of the clamping member distal to a piston disposed at a proximal end of the clamping rod. The cylinder is operatively associated with a moveable handle such that as the moveable handle is moved towards an actuated position, the cylinder is moved proximally such that the biasing member urges the clamping rod proximally to move the first and second jaw members towards the clamped position.