Networking tools
CIDR maths, subnetting and address planning
Subnet planning is arithmetic nobody should do by hand twice. Expand a CIDR block into its usable range, split a network into evenly sized subnets, and check whether two blocks overlap before you apply the change.
2 Networking tools
CIDR Calculator
Networking
Expand an IPv4 CIDR block into its network, range, mask and host count.
Runs in your browser
Subnet Calculator
Networking
Split a network into evenly sized subnets and plan address allocation.
Runs in your browser