Calculate IPv4 subnets from CIDR or a subnet mask. See network, broadcast, usable host range, wildcard mask and host count, and split a network into smaller subnets.
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How to use the IPv4 Subnet Calculator
Enter an address like 192.168.1.130/26, or an address and mask.
Optionally set a prefix length to split the network into subnets.
Read the details, the summary table and the subnet list.
Why use this IPv4 Subnet Calculator
Complete detailsNetwork, broadcast, mask, wildcard, first and last host, usable hosts and class.
Flexible inputCIDR, address plus dotted mask, or a single IP address.
Subnet splittingDivide a network into equal smaller subnets and list each one.
Address typeShows whether the address is private, public, loopback or link-local.
Frequently asked questions
How do I find the usable hosts in a /26?
A /26 has 64 addresses, of which 62 are usable because the network and broadcast addresses are reserved.
What is a wildcard mask?
It is the inverse of the subnet mask. Access control lists often use it, for example 0.0.0.63 for a /26.
How do /31 and /32 work?
A /31 has two addresses for point-to-point links and a /32 is a single host, so neither has a separate broadcast address.