European helicopter - works with metric values
but they are so kind, to provide you with :
1.) Standard Atmosphare Table (1-13) which shows hPa and in.Hg
2.) Conversion Chart
3.) numbers: 1 hPa (mbar) = 0,02953 in.Hg // 1 in.Hg = 33,865 hPa (mbar)
;.-) ;-) ;-)