Subnet Calculator
Work out the network address, broadcast, host range and host count for any IPv4 CIDR block.
Usable hosts254
Total addresses256
- Network address
- 192.168.1.0
- Broadcast address
- 192.168.1.255
- First usable host
- 192.168.1.1
- Last usable host
- 192.168.1.254
- Subnet mask
- 255.255.255.0
- Wildcard mask
- 0.0.0.255
192.168.1.0/24
The prefix (CIDR) sets how many leading bits are the network — the rest address hosts. A /24 has 2⁸ = 256 addresses, but the network and broadcast addresses aren't assignable, leaving 254 usable hosts (192.168.1.1 – 192.168.1.254). A /31 carries just two addresses for point-to-point links (RFC 3021) and a /32 is a single host. All bit math runs in your browser.
Questions
How many hosts are in a /24?
A /24 has 2⁸ = 256 addresses, but the network and broadcast addresses are reserved, leaving 254 usable hosts — for 192.168.1.0/24 that is 192.168.1.1 through 192.168.1.254, with 192.168.1.255 as broadcast.
What is a wildcard mask?
It is the bitwise inverse of the subnet mask (255.255.255.0 → 0.0.0.255). Routers and ACLs use wildcard masks to match ranges of addresses.
Why do /31 and /32 behave differently?
A /32 is a single host route. A /31 is a two-address point-to-point link where, under RFC 3021, both addresses are usable and there is no separate broadcast — so the usual 'minus 2' rule doesn't apply.