Open question: Do they bring working on and Währungsumechnung in position?

Hello has I a question over determining position size in the currencies. now I know this position dimensional equation from the stock exchange $Risk/Ssize = No. of the portions. now I reached to convert this in $risk/Zacken (x10) = volumes. (Points/teeth must be x10 because of the return $10 on sex disease lots.) So, if I risk $1000 by 20 points/teeth. (1000/200 = 5). 5 sex disease lots on an equal footing. but this is so correct in my low currency (AUD) only if I buy the EUR/USD for example. the risk is then 2%. Have all possible ideas up, how one takes this formula and to it, this a Währungsumechnung must add for all currencies to work.