The result of your conversion between watthour and grain/gallon [UK] appears here
To convert between Watthour and Grain/gallon [UK] you have to do the following:
First divide 3600 / ((0.45359237/16)*(192/175)/480)/0.00454609 = 252564.80394501
Then multiply the amount of Watthour you want to convert to Grain/gallon [UK], use the chart below to guide you.
Symbol: Wh
No description
Symbol: gr/gal
No description