The three tiers

Traders who use a fixed size rarely use only one. They use a short ladder, chosen before the session starts.

Normal

The size the last lessons produced. On the 4,000 dollar account that is 0.05 lot on gold.

At the narrowest usual stop of 8 dollars it costs 40 dollars, which is one percent. This is the default, and most days use it.

Normal is the calculated fixed size, and it is the top of the ladder for you.

De-risk

Half of normal, for a day you already expect to be difficult.