Is it a good idea to dry your grain? With prices low, that's a good question.

I looked for a method of how to calculate for an answer. I turn to Bob Fanning, SDSU Extension Plant Pathology Field Specialist.

He offers such a method. He instructs to calculate cost.

The propane cost to dry a bushel of grain one percentage point of moisture can be estimated by multiplying the propane cost per gallon by 0.02. One propane distributor reports propane at $1.60 per gallon, which would result in $0.032 per bushel per  point of moisture or $0.32 for 10 percentage points.

By dividing the propane cost to dry grain by the grain price, you can calculate the percentage of grain loss that will equal the drying cost. Using $1.60/gallon  for propane, and $2.50 per bushel for corn, $0.32/$2.50 = 0.128 or 12.8 percent.