Subnet Calculator
Enter an IP address in CIDR notation to calculate subnet details.
Network address, broadcast, host range, masks, and more.
Results for 192.168.1.0/24
What is CIDR notation?
CIDR (Classless Inter-Domain Routing) notation combines an IP address with a prefix length to describe a network. For example, 192.168.1.0/24 means the first 24 bits identify the network and the remaining 8 bits are available for host addresses — giving 256 total addresses and 254 usable hosts (the network and broadcast addresses are reserved).
Common subnet masks
| CIDR | Subnet Mask | Usable Hosts |
|---|---|---|
| /8 | 255.0.0.0 | 16,777,214 |
| /16 | 255.255.0.0 | 65,534 |
| /24 | 255.255.255.0 | 254 |
| /25 | 255.255.255.128 | 126 |
| /26 | 255.255.255.192 | 62 |
| /27 | 255.255.255.224 | 30 |
| /28 | 255.255.255.240 | 14 |
| /30 | 255.255.255.252 | 2 |
Network address vs broadcast address
Every subnet has two reserved addresses that cannot be assigned to hosts. The network address is the first address in the range (all host bits set to 0) and identifies the subnet itself. The broadcast address is the last address (all host bits set to 1) and is used to send packets to every device on the subnet simultaneously. The usable host range sits between these two.
When to use a /30 subnet
A /30 subnet provides exactly 2 usable host addresses, making it ideal for point-to-point links between two routers. Using a /30 rather than a /24 conserves IP address space and keeps routing tables clean. For loopback interfaces or single-host assignments, a /32 is used.
Private IP address ranges
- 10.0.0.0/8 — up to 16.7 million addresses (Class A private)
- 172.16.0.0/12 — up to 1 million addresses (Class B private)
- 192.168.0.0/16 — up to 65,536 addresses (Class C private, most home networks)
These ranges are not routable on the public internet and are reserved for use within private networks. NAT (Network Address Translation) allows devices using private IPs to communicate with the internet through a single public IP.