Visual Subnet Calculator

Enter a network address and CIDR prefix to visually split it into smaller subnets and see how address space is allocated across your infrastructure. Divide, merge, and label subnet blocks interactively with a graphical subnet map — ideal for network design, IP planning documentation, and VLSM visualization. Save your subnet plan or IP ranges in a free notepad at Notepadly. The vlsm calculator allocates multiple subnets of different sizes from a parent block — maximising address space efficiency.