A typical office /24
192.168.1.10/24
Network: 192.168.1.0/24 Broadcast: 192.168.1.255 Usable hosts: 192.168.1.1 – 192.168.1.254 (254 addresses)
CIDR / Subnet Calculator
Get network address, broadcast, netmask and usable host range from any CIDR block.
e.g. 192.168.1.10/24
This address falls inside a private (RFC 1918) or loopback range.
Private
- Network address
- 192.168.1.0/24
- Broadcast address
- 192.168.1.255
- Subnet mask
- 255.255.255.0
- Wildcard mask
- 0.0.0.255
- Usable host range
- 192.168.1.1 – 192.168.1.254
- Usable hosts
- 254
- Total addresses
- 256
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About this tool
CIDR notation (Classless Inter-Domain Routing) packs a network's size into the address itself: 192.168.1.0/24 means the first 24 bits are the fixed network portion and the remaining 8 bits identify hosts within it. Every router, firewall rule and cloud VPC uses this notation.
This calculator does the bit arithmetic for you: given any IP address and prefix length, it derives the network address, broadcast address, subnet mask and the exact range of usable host addresses.
How to use it
- Enter an IP address followed by a slash and a prefix length, e.g. 10.0.0.5/22.
- The result updates immediately: network, broadcast, netmask, wildcard mask, and the first and last usable host.
- A badge marks the block as private (RFC 1918) or public.
Examples
Common problems
- The usable host count shows 0.
- A /31 or /32 block has no room for a separate network and broadcast address. /31 is the standard for point-to-point links (RFC 3021); /32 identifies a single host.