Grain Corn Production Estimator

Standing in a representative spot of the field, you can predict bushels per acre with a tape measure and a sharp eye. The math has been used in land-grant extension publications for decades:

bu/acre = (plants/acre × kernels around × kernels long) ÷ 90,000

The 90,000is the standard kernels-per-bushel constant for #2 yellow dent corn at 15.5% moisture — the USDA marketing standard. In a tough year (small kernels, light test weight) bump it up to 95,000; in a great year (deep kernels) drop it to 80,000–85,000. The Advanced section in the calculator lets you override it.

Plants per acre— walk a 1/1000th-acre row segment (17 ft 5 in for 30″ rows) and count emerged plants; multiply by 1,000.

Kernels around— count one full ring around a representative ear. Skip ears with frost or insect damage; you want a realistic average.

Kernels long— count one row from butt to tip on the same ear, stopping at the last fully-formed kernel.

Sample 3–5 spots across the field and average the inputs for a real-world estimate. The tool gives you a per-ear-and-population yield estimate; reality will land within roughly ±10% of it.