A surgical instrument (10, 3500), comprising: a handle (14, 3502); a shaft (200, 2004, 3406) having a proximal end and a distal end, wherein the shaft is removably coupled to the handle at the proximal end; and an end effector (3000, 3100, 3150, 3200, 3250, 3300, 3350, 3400, 3600, 3650, 3800, 3850, 3900) coupled to the distal end of the shaft, the end effector comprising: a first jaw member defining an anvil (3002, 3102, 3152, 3202, 3252, 3302, 3352, 3602, 3652, 3802, 3852, 3902, 3404, 3452); a second jaw member (3004, 3104, 3154, 3204, 3254, 3304, 3354, 3604, 3654, 3804, 3854, 3904, 3402) configured to receive a cartridge therein, wherein the first jaw member is moveable with respect to the second jaw member; a first sensor (3008a, 3108a, 3158, 3258, 3808, 3858) coupled to the anvil, wherein the first sensor is configured to measure a gap between the anvil and the second jaw member; and a second sensor (3008b, 3108b, 3160a, 3160b, 3260a... 3260d, 3812, 3880), wherein the first sensor and the second sensor are in signal communication with a processor; wherein the second sensor is configured to measure a strain or pressure on the anvil when tissue is clamped between the jaws, the instrument comprises the processor, characterized in that the processor is configured to modify the measurement of the gap by the first sensor using the strain or pressure on the anvil measured by the second sensor, to more accurately represent the true compressed tissue thickness in case of a partial bite of tissue. a handle (14, 3502); a shaft (200, 2004, 3406) having a proximal end and a distal end, wherein the shaft is removably coupled to the handle at the proximal end; and an end effector (3000, 3100, 3150, 3200, 3250, 3300, 3350, 3400, 3600, 3650, 3800, 3850, 3900) coupled to the distal end of the shaft, the end effector comprising: a first jaw member defining an anvil (3002, 3102, 3152, 3202, 3252, 3302, 3352, 3602, 3652, 3802, 3852, 3902, 3404, 3452); a second jaw member (3004, 3104, 3154, 3204, 3254, 3304, 3354, 3604, 3654, 3804, 3854, 3904, 3402) configured to receive a cartridge therein, wherein the first jaw member is moveable with respect to the second jaw member; a first sensor (3008a, 3108a, 3158, 3258, 3808, 3858) coupled to the anvil, wherein the first sensor is configured to measure a gap between the anvil and the second jaw member; and a first jaw member defining an anvil (3002, 3102, 3152, 3202, 3252, 3302, 3352, 3602, 3652, 3802, 3852, 3902, 3404, 3452); a second jaw member (3004, 3104, 3154, 3204, 3254, 3304, 3354, 3604, 3654, 3804, 3854, 3904, 3402) configured to receive a cartridge therein, wherein the first jaw member is moveable with respect to the second jaw member; a first sensor (3008a, 3108a, 3158, 3258, 3808, 3858) coupled to the anvil, wherein the first sensor is configured to measure a gap between the anvil and the second jaw member; and a second sensor (3008b, 3108b, 3160a, 3160b, 3260a... 3260d, 3812, 3880), wherein the first sensor and the second sensor are in signal communication with a processor; wherein the second sensor is configured to measure a strain or pressure on the anvil when tissue is clamped between the jaws, the instrument comprises the processor, characterized in that the processor is configured to modify the measurement of the gap by the first sensor using the strain or pressure on the anvil measured by the second sensor, to more accurately represent the true compressed tissue thickness in case of a partial bite of tissue.