Subnet Mask Calculator
Enter an IPv4 address with a dotted mask or a prefix length to get the network address, broadcast, usable host range, wildcard mask and total capacity. Need a certain number of subnets or hosts per subnet instead? The calculator borrows host bits for you, tells you the prefix to use and lists the resulting subnets with their ranges.
How to use
Netmask, wildcard, host capacity and subnet splits for any IPv4 address. Your data is processed only inside this browser tab.
FAQ
How many hosts really fit?
Two to the power of the remaining host bits, minus the network and broadcast addresses — with the /31 point-to-point and /32 single-address exceptions applied.
Why is my address labelled private?
RFC 1918, loopback, link-local and multicast blocks are marked so you notice when a public plan is being built on private space.
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