A wheel loader comprising: a vehicle body (5, 9); a working device that includes a lift arm, a lift arm cylinder, a bucket, a bucket cylinder, and a link mechanism, the lift arm being disposed at the front of the vehicle body and coupled to the vehicle body (5, 9) via a hinge pin, the lift arm cylinder being supported to the vehicle body (5, 9) and rotating the lift arm in a vertical direction, the bucket being coupled to a tip of the lift arm, the bucket cylinder being supported to a position different from the lift arm cylinder of the vehicle body (5, 9) and rotating the bucket in the vertical direction, the link mechanism being disposed between the bucket cylinder and the bucket and including a bell crank and a push rod; a lift arm angle sensor that detects the angle of the lift arm; a pressure sensor (15a, 15b) that detects the pressure of the lift arm cylinder; a control device (30, 130) that calculates a load on the bucket; and a vehicle body information database that stores vehicle body information including dimension data related to the link mechanism on the working device (27, wherein, in an unloaded state of the bucket, the control device (30, 130) calculates an unloaded moment, namely, the moment around the hinge pin, from the pressure of the lift arm cylinder that is detected by the pressure sensor (15a, 15b), the angle of the lift arm that is detected by the lift arm angle sensor, and the dimension data extracted from the vehicle body information database, in a loaded state of the bucket, the control device (30, 130) calculates a loaded moment, namely, the moment around the hinge pin, based on a moment around the hinge pin due to a force applied to the lift arm cylinder and a moment around the hinge pin due to a force applied to the bucket cylinder calculated from the pressure of the lift arm cylinder that is detected by the pressure sensor (15a, 15b), the angle of the lift arm that is detected by the lift arm angle sensor, and the dimension data extracted from the vehicle body information database, and the control device (30, 130) calculates the load on the bucket by dividing the difference between the calculated unloaded moment and the loaded moment by the horizontal distance (L W) between the hinge pin and the gravity center position of the bucket. a vehicle body (5, 9); a working device that includes a lift arm, a lift arm cylinder, a bucket, a bucket cylinder, and a link mechanism, the lift arm being disposed at the front of the vehicle body and coupled to the vehicle body (5, 9) via a hinge pin, the lift arm cylinder being supported to the vehicle body (5, 9) and rotating the lift arm in a vertical direction, the bucket being coupled to a tip of the lift arm, the bucket cylinder being supported to a position different from the lift arm cylinder of the vehicle body (5, 9) and rotating the bucket in the vertical direction, the link mechanism being disposed between the bucket cylinder and the bucket and including a bell crank and a push rod; a lift arm angle sensor that detects the angle of the lift arm; a pressure sensor (15a, 15b) that detects the pressure of the lift arm cylinder; a control device (30, 130) that calculates a load on the bucket; and a vehicle body information database that stores vehicle body information including dimension data related to the link mechanism on the working device (27, wherein, in an unloaded state of the bucket, the control device (30, 130) calculates an unloaded moment, namely, the moment around the hinge pin, from the pressure of the lift arm cylinder that is detected by the pressure sensor (15a, 15b), the angle of the lift arm that is detected by the lift arm angle sensor, and the dimension data extracted from the vehicle body information database, in a loaded state of the bucket, the control device (30, 130) calculates a loaded moment, namely, the moment around the hinge pin, based on a moment around the hinge pin due to a force applied to the lift arm cylinder and a moment around the hinge pin due to a force applied to the bucket cylinder calculated from the pressure of the lift arm cylinder that is detected by the pressure sensor (15a, 15b), the angle of the lift arm that is detected by the lift arm angle sensor, and the dimension data extracted from the vehicle body information database, and the control device (30, 130) calculates the load on the bucket by dividing the difference between the calculated unloaded moment and the loaded moment by the horizontal distance (L W) between the hinge pin and the gravity center position of the bucket.