How to calculate laminar boundary layer thickness on a flat plate

[@mikhailyatsevitch7703]

Isn't the cut off for laminar flow over a flat plate at Re ~ 600?

[@jasonknight6745]

the critical value is 300000

[@heysamhillier]

if calculating boundary layer thickness for a wing at a fixed location (0.28m) but at different velocities, when the RE is over 300000 should I change to turbulant (Xx0.381REx^-02)?

[@blandersen]

yes@@heysamhillier

[@nabeel223903]

isnt the re to high to be laminar?

[@jasonknight6745]

for a pipe/duct, yes, but for a flat plate where Re is based on length the critical value is around 300000