subnet – subnet

I need your help!

I have a network (LAN)(over 200 PC) in one subnet 192.168.15.0
I need to devide it into 4 subneworks: 192.168.12.0; 192.168.13.0; 192.168.14.0; 192.168.15.0.
My Question: Do I need Routers to route packets between this subnetworks??

I think if i’ll make 192.168.12.0/22 the clients with IP 192.168.12.1 will easy acces IP 192.168.15.1.

Am i right? Will i have problems??

THX!