The result of your conversion between perch and cawney appears here
To convert between Perch and Cawney you have to do the following:
First divide 25.29285264 / (4/3) * (0.09290304*43560) = 0.0046875
Then multiply the amount of Perch you want to convert to Cawney, use the chart below to guide you.
Symbol: perch
No description
Symbol: cawney
No description