The general rule of thumb is at least 1 EV charger for every 10-15 EVs, but we've seen building owners opting for 1 EV charger for 5-8 every EVs in fast-adopting states like California.
Determining how many EV chargers should be on your site is a function of demand, particularly the number of EVs that will likely be on your site and cost, or how much each charger will cost you to set-up and maintain.
In some cases, leasing a spot to a DCFC in a highly-frequented destination can lead to modest revenue — currently estimate between $2k and $10k per spot. In others, they come with a cost, $10k per Level 2 charger in order to meet the increasing demand for vehicle charging.