The present invention is an improved grain drill and a method retrofitting a previously manufactured grain drill to provide accurate weight determination of seed in a seed hopper of the grain drill. A grain drill in accordance with the invention includes a frame having a plurality of wheels for supporting the grain drill during rolling over a surface of ground to be planted with seed grain; a hopper for containing the seed grain to be planted in the ground; a support which is joined to opposed sides of the frame and to spaced apart locations of the hopper to transfer weight of the hopper to the frame, the support including at least one weight sensing device which senses a weight of seed grain in the hopper transferred through the support to the frame and provides an output of the sensed weight of the seed grain in the hopper; and a display, coupled to the output, for displaying the weight of the seed grain contained in the hopper.