IP Subnet Calculator
Calculate IPv4 subnets, split networks into subnets, plan address space with visual binary breakdown and exportable subnet plans.
How to Use IP Subnet Calculator
- 1Enter an IPv4 address and select a CIDR prefix length (e.g. 192.168.1.0/24).
- 2View the calculated subnet details including network address, broadcast address, usable host range, and subnet mask.
- 3Use the split feature to divide the network into smaller subnets for planning.
- 4Export the subnet plan as a table for documentation or network configuration.
Frequently Asked Questions
What is a subnet?
A subnet (subnetwork) is a logical subdivision of an IP network. Subnetting divides a large network into smaller, more manageable segments, improving security, reducing broadcast traffic, and making IP address allocation more efficient.
What is CIDR notation?
CIDR (Classless Inter-Domain Routing) notation expresses an IP address and its associated network prefix length in the form "192.168.1.0/24". The number after the slash indicates how many bits of the address identify the network, with the remaining bits available for host addresses.
How many usable hosts are in a /24 subnet?
A /24 subnet has 256 total addresses (2^8), but two are reserved: one for the network address and one for the broadcast address. That leaves 254 usable host addresses.
Is this processed locally?
Yes. All subnet calculations are performed entirely in your browser. No data is sent to any server.