Estimating Final Grain Yield in Corn

Yield Component “Ballpark” Method

Select several sites in the field. At each site, measure off a length of row equal to 1/1000th acre:

1/1000th of an Acre

Row Width


Row Length

(Foot, Inches)

15 34' 8"
20 26' 1"
30 17' 5"
36 14' 5"
38 13' 9"
40 13' 1"


Count the number of harvestable ears in the 1/1000th acre. On every 5th ear, count the number of kernel rows per ear and determine the average. On the same ears, count the number of kernels per row and determine the average. Calculate estimated yield for each site in the field by multiplying ear number by average row number by average kernel number, then dividing that result by 90.

(Ear Number X Average Row Number X Average Kernel Number) ÷ 90 = Estimated Yield for Site

The value of "90" represents the average kernel weight (90,000 kernels/56 lb. bushel). Repeat the procedure for each site and average the yields of all sites to estimate yield for the field. For example, let's say in Site #1 you counted 35 harvestable ears. Sampling every 5th ear resulted in an average row number of 16 and an average number of kernels per row of 36. The estimated yield for that site would (35 x 16 x 36) ÷ 90, which equals 224 bu/ac.