How many public EV charging stations are needed within a market to support the charging needs of owners of EVs within a market? The minimum acceptable ratio is actually going to vary a fair amount by the unique combination of factors in each region and market, which is the focus of a follow-on article. With that said, however, my belief is that at least for the next 5-7 years, a ratio of 15-20 to 1 will in fact meet demand in most markets.