How many usable hosts are in a /24?
254 on a normal subnet. The network address and the broadcast address are not hosts. /31 and /32 are treated as point-to-point and host routes, so the usable count is the whole prefix.
IPv4
Subnet calculator
Network, broadcast, and usable hosts for an IPv4 prefix. The math runs in your browser. Nothing is sent when you calculate.
Submit an address and a prefix from 0 to 32.A /24 has 256 addresses. Two of them, the network and the broadcast, are not hosts on a normal subnet. /31 and /32 are treated as point-to-point and host routes, so the usable count is the whole prefix.