Subnet calculator

CIDR in — network, range, mask and host count out. IPv4 and IPv6.

Network address— the first address; identifies the subnet itself
192.168.1.0
Subnet mask— which bits are network vs host
255.255.255.0 · /24
First usable host
192.168.1.1
Last usable host
192.168.1.254
Broadcast address— the last address; reaches every host at once (IPv4 only)
192.168.1.255
Usable hosts— total minus network and broadcast (/31 and /32 are special)
254

● computed in your browser · the input never leaves this page

  • Network, broadcast, usable range and mask formats.
  • IPv6 with power-of-two address counts.
  • Entirely in your browser — the input never leaves this page.