This calculator will provide the winding data for our transformers. It has the core data built in for many cores but in case your core is unknown it has a function for that too.
The first step is to download and install the calculator. You can do the math if you like but I will use the calculator.
Since we don't always know the core type I will go thru the steps to determine the core parameter first.
(this requires an inductance meter or test procedure to determine the inductance.) The calculator also ID's cores by color code.
Select the first option.