I load my brush with Rosso directly out of the ceramic pot, so I don't know how much soap I use each shave. I can tell you I've had perhaps 15 great shaves with the Rosso, and I can't even notice any reduction in the amount of soap in the pot. I even compared the fill level of my new pot of Verde to my used pot of Rosso, and couldn't see a difference. This stuff, for me, will last a really long time.
--Scott