Lot size based on risk management question

Beginner Questions
1

Hello All,

Can someone try to explain to me what is the mathematical calculation of lot size for my situation hereunder?
I am using a demo account to test an expert advisor, one of the criteria within the EA is that I can set the risk management to 10%
The account started with 100 dollars, the first few trades automatically opened at 0.01 lot, once the balance reached about 105 dollars,
I noticed each trade was opened with 0.02 lot. I have now a balance of 135 dollars and it’s still using 0.02 lots.

My question is, can I mathematically calculate when will the EA start opening trades with 0.03? What does the balance needs to be?

If you need more info please let me know.

Regards
Nic

2

Is it possible to set fixed risk on position?

For example, we risk $50 in each trade, so we need to calculate the next way: Risk / Stop Size = Position Size.

3

If you have a trading plan then be disciplined and follow it consistently.

4

Does the EA trade same pair? Might increaselot size because of diferent pip value, or there is a rounding in the calculation and actual risk size which was previously 0.01.44x got rounded to 0,01, and as your equity rised you could get to 0.0147 or more and got rounded to 0.02.

I don’t use EAs but I also use snowball effect on my lotsizes as my acc got from 1,300 € equity to 2000 I let the money work for me.