IP Subnet Calculator
Enter an IPv4 address with CIDR prefix (e.g. 192.168.1.0/24) to get the network address, broadcast address, subnet mask, usable IP range, and total host count. Everything computed in your browser.
Common CIDR Reference:
/8 — 16,777,216 hosts (Class A)
/16 — 65,536 hosts (Class B)
/24 — 256 hosts (Class C)
/28 — 16 hosts
/32 — 1 host (single IP)
/8 — 16,777,216 hosts (Class A)
/16 — 65,536 hosts (Class B)
/24 — 256 hosts (Class C)
/28 — 16 hosts
/32 — 1 host (single IP)
What a Subnet Calculator Shows
A CIDR address like 192.168.1.0/24 packs both an IP range and a subnet mask into one value. This calculator expands it into the network address, broadcast address, usable host range, and mask, which is exactly what you need when configuring routers, firewalls, or cloud security groups.
How to Read the Results
- The network address is the first address in the block
- The broadcast address is the last address and is not usable by hosts
- Usable IPs are the addresses between network and broadcast
- A smaller prefix, like /24, means more hosts; a larger prefix, like /30, means fewer
Why are two addresses missing from the range?
IPv4 reserves the network address and the broadcast address, so they cannot be assigned to a device.