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Q & A IP & Network · September 11, 2026

How many hosts fit in a /16?

65,536 total addresses; 65,534 usable. Formula: 2^(32 - prefix). For /16 that’s 2^16 = 65,536. Subtract 2 for the network address (all-host-bits-zero) and broadcast (all-host-bits-one), which cannot be assigned to hosts.

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CIDR Subnet Math Explained: /24, /16, /8, and Everything Between
CIDR notation is how modern networks are described: an IP address plus a slash and a number counting the network-prefix bits. Everything left of the boundary is the network; everything right is the host. The math is simpler than the notation makes it look.
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