OK. I think I finally understand it now.
You just need to multiply the ACCOUNT VALUE (a.k.a. TOTAL FUNDS) by 1.5 to find out how much funds you need to add to maintain your current margin indicator percentage.
Did somebody already say that?
@obrienciaran, I think I’ve figured out how to do the calculation you need for your calculator if you need any assistance. You mentioned FREE FUNDS in your answer above, but my calculation doesn’t use that figure at all.
Here is my provisional formula to calculate how much funds are required (fr) to achieve any target margin indicator percentage (tm):
fr = ((2.5 * bf) / ((1 / (tm / 100)) - 1)) - av
Where:
fr = funds required
av = available funds
bf = blocked funds
tm = target margin (expressed as a percentage)
Can people test this before anybody relies on it?