No one can give you an exact answer. Might last a day, might last a month. All depends on your eliquid, what it contains, how you draw, how long you fire the coil, the amount of power to the coil, etc..etc... ect..
For me, a SSOCC lasts about 3 weeks. I'm a heavy vaper, yet I have multiple devices, only 1 is SSOCC right now, it has a lightly colored eliquid, with sweetener, .3 ohms fired at 35 watts with about 4ml going through it a day.
For the wife, her SSOCC's (3 devices) last about 6 weeks, .3 ohms fired at 20 watts, same type of eliquids as mine, maybe 3ml a day in each.
YMMV