Network planning Local
IPv4 Subnet Calculator
Calculate network addresses, host ranges, and masks from CIDR or dotted-decimal input.
Processed in your browser. Your input is not uploaded.
01
Input
Accepted: 192.168.1.130/26, 192.168.1.130 255.255.255.192, 192.168.1.130 0.0.0.63, or 192.168.1.130 #50.
02
Output
Run the tool to see the result.
Calculation notes
The network address is the address AND the mask. Ordinary subnets exclude the network and directed broadcast addresses from usable counts. A /31 has two point-to-point endpoints; a /32 is a single host route. Host-count mode reserves two addresses and chooses the smallest conventional subnet that fits. An all-zero dotted mask means /0; use CIDR to avoid ambiguity. Scope labels cover common ranges and are not a full special-use address registry.