A method of balancing a beam pumping unit can include securing counterweights to crank arms, thereby counterbalancing a torque applied at a crankshaft at a maximum torque factor position due to a polished rod load and any structural unbalance. A well system can include a beam pumping unit including a gear reducer having a crankshaft, crank arms connected to the crankshaft, a beam connected at one end to the crank arm and at an opposite end to a rod string polished rod, and counterweights secured to the crank arms, and in which a torque applied at the crankshaft at a maximum torque factor position due to weights of the crank arms, the counterweights and wrist pins equals a torque applied at the crankshaft at the maximum torque factor position due to a load applied to the beam via the polished rod and any structural unbalance.