A torque output tool (100, 100b), comprising: an output shaft for outputting torque; a motor for driving the output shaft to rotate around a first axis; a housing for supporting the motor; a transmission assembly for transmitting output of the motor to the output shaft; and a gearbox for accommodating at least a portion of the transmission assembly; wherein the transmission assembly comprises: a first planetary gearset comprising first planet gears and a first planet carrier, wherein the first planet gears are driven by the motor, and the first planet carrier is used for mounting the first planet gears; and a second planetary gearset comprising second planet gears and a second planet carrier, wherein the second planet carrier is used for mounting the second planet gears; wherein the transmission assembly is capable of being switched to a first state and a second state such that the transmission assembly outputs a first gear ratio or a second gear ratio separately, wherein the first gear ratio is greater than the second gear ratio; wherein the motor comprises: a motor shaft that rotates around the first axis; wherein the transmission assembly comprises: a sun gear fixedly connected to the motor shaft; wherein each of the first planet gears comprises: an external engagement portion that forms external engagement with the sun gear; and an internal engagement portion fixedly connected to the external engagement portion; characterized in that a length of the gearbox in an axial direction of the first axis is greater than or equal to 38 mm and less than or equal to 46 mm. an output shaft for outputting torque; a motor for driving the output shaft to rotate around a first axis; a housing for supporting the motor; a transmission assembly for transmitting output of the motor to the output shaft; and a gearbox for accommodating at least a portion of the transmission assembly; wherein the transmission assembly comprises: a first planetary gearset comprising first planet gears and a first planet carrier, wherein the first planet gears are driven by the motor, and the first planet carrier is used for mounting the first planet gears; and a second planetary gearset comprising second planet gears and a second planet carrier, wherein the second planet carrier is used for mounting the second planet gears; a first planetary gearset comprising first planet gears and a first planet carrier, wherein the first planet gears are driven by the motor, and the first planet carrier is used for mounting the first planet gears; and a second planetary gearset comprising second planet gears and a second planet carrier, wherein the second planet carrier is used for mounting the second planet gears; wherein the transmission assembly is capable of being switched to a first state and a second state such that the transmission assembly outputs a first gear ratio or a second gear ratio separately, wherein the first gear ratio is greater than the second gear ratio; wherein the motor comprises: a motor shaft that rotates around the first axis; wherein the transmission assembly comprises: a sun gear fixedly connected to the motor shaft; wherein each of the first planet gears comprises: an external engagement portion that forms external engagement with the sun gear; and an internal engagement portion fixedly connected to the external engagement portion; characterized in that a length of the gearbox in an axial direction of the first axis is greater than or equal to 38 mm and less than or equal to 46 mm.