Calculate Lot Size for Currency Euro

Hello everyone,
this question might have already been here but I am totally confused so I am sorry that I might duplicate it.
I am working with the ATR and would like to calculate the Lot Size for different pairs like EURUSD, USDCAD, GBPCAD and so on. My account currency is Euro and I have a demo account with 100.000 Euros on it. I want to risk 1% of my account balance. I already tried different formulas and nothing seems to work correctly. When I enter a trade my stop loss value is like always below the 1% value of my balance. I think it might be because I need to calculate the value of a pip in Euro right? But how do I do it and how do I include it into the formula? I have already tried stuff like:

new_position_size = one_percent_of_account_balance / (atr_as_pip * 10)
or
new_position_size = ((account_balance * 1%) % pip amount of sl) / 100k

Nothing works the way it should.

Can someone please explain me how it is calculated?
Again I am sorry for my stupidity.

Don’t have much time to help you out with this but I can perform a quick search though and offer you this link?

Unless you’ve already checked that one out and hasn’t really worked for you?