CS>Conversion table

[RodStevenson]

Hi List,
Does anyone out there, know the conversion rate between us/cm and megohms? 
Lately, Ive been reading about lab grade DW, the figure they give for "critical 
procedures" is 18.2 Mw, and I would like to know just how my home DW rates 
against this. I've found that  0.1 us/cm = 10 Mw, but I'm unsure about any 
conversion rate. Any ideas?
TIA
Rod Stevenson