Would it be possible to include these in our flight plans from Simbrief / Navigraph
The formula
For Critical Point we use the formula P = (D x H) / (O + H) (2). To find our time to turn around, we use the formula: Time = P/G. For these formulas, P is the critical point; D is the total distance to fly; O is reduced ground speed outbound; H is reduced groundspeed home; and G is the groundspeed outbound.
A GREAT READ here