A balancing method and a balancing device (100, 101, 200, 201, 301, 303) for determining a fluid balance between a flow quantity in a first flow path (FW1) and a flow quantity in a second flow path (FW2) are disclosed. The disclosed balancing device (100, 101, 200, 201, 301, 303) comprises the following elements: a differential flow measuring unit (D) for measuring the differential flow between a flow in the first flow path (FW1) and a flow in the second flow path (FW2), a branch from one of the two flow paths (FW1, FW2) for diverting fluid from one of the two flow paths into the other flow path (W), a device for setting the flow quantity (P11, P12) in the additional flow path, which can be controlled in such a way that the measured differential flow fulfills a predetermined condition, and with a device (K) for determining the flow quantity in the additional flow path as a measure of the fluid balance.