Subnet and IP calculator
Work out the details of any network from an address and prefix or mask. See the network and broadcast addresses, the host range, the wildcard mask and the binary layout, then split a network into equal parts, plan subnets by host count, convert an address range to CIDR blocks or check whether an address belongs to a list of networks.
Tooloat runs in your browser and needs JavaScript. It opens in a moment, and your files are processed on your device.
How it works
- Enter an address with a prefix or mask.
- Read the network details.
- Use the tabs to split, plan, convert ranges or test membership.
Why use it
- IPv4 and IPv6 with big number support.
- VLSM planning and even splits.
- Range to CIDR and network aggregation.
- Address type, class and reverse DNS.
Questions and answers
How many hosts are in a /24?
A /24 has 256 addresses and 254 usable hosts, because the network and broadcast addresses are reserved.
What is a wildcard mask?
It is the inverse of the subnet mask and is used in some router access lists.
Does it work for IPv6?
Yes, including compression and expansion of addresses.
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