This simple script provides a way of calculating position size on a bar by bar basis for a fixed risk amount.
If you are trading a fixed risk amount (e.g. $100) per trade and your Entry and Stop is defined by a specific bar on the chart (any resolution e.g. 15 min, 5 min, 2 min etc) then this indicator will show you the position size you can take.
The user configures the risk amount per trade in the setting for the indicator, the default is 100 (e.g. $100).
It calculates each bar size (high - low) for the resolution of the chart that is being viewed.
The position size = (risk amount) / (bar size).
It then displays a "." (dot) for each bar and to see the position size hover your mouse over this dot.
The pane for this indicator can be set to the top of the chart by using the "Move pane up" option on the chart so that the indicator is easily accessible and discrete at the top of the chart.
Also, there is an option to use this indicator as a substitute for the built-in volume display.