IP Address Tools
Subnet calculator, CIDR converter, and IPv4/IPv6 address analysis
How to Use the IP Address Tools
- Enter an IPv4 address with optional CIDR notation (e.g.
192.168.1.0/24). - Click Calculate for full subnet details.
Shows network/broadcast addresses, host range, total hosts, IP class, private range detection, and binary representation.
What is IP Address & Subnet Tools?
The IP Address Tools suite provides IPv4 and IPv6 subnet calculation, CIDR prefix translation, netmask analysis, IP binary representation, and IP range expansion. Network engineers and system administrators can input any IP with CIDR notation (such as `192.168.1.0/24`) to instantly view network address, broadcast address, usable host ranges, and total addressable nodes.
Common Uses
- Designing VPC subnets and routing tables in AWS, Azure, and Google Cloud
- Configuring firewall rules, security groups, and access control lists (ACLs)
- Troubleshooting local subnet overlaps, default gateway misconfigurations, and netmasks
- Translating between dotted-decimal netmasks (255.255.255.0) and CIDR prefixes (/24)
Frequently Asked Questions
What does CIDR notation (e.g. /24) mean?
CIDR (Classless Inter-Domain Routing) notation specifies the number of leading bits in the IP address allocated to the network prefix. For example, `/24` means the first 24 bits belong to the network, leaving 8 bits for 256 host addresses (254 usable).
What is the difference between public and private IP addresses?
Private IP ranges (defined in RFC 1918, such as 10.0.0.0/8, 172.16.0.0/12, and 192.168.0.0/16) are reserved for internal networks and are not routable on the public internet without NAT.
Does this tool support IPv6 subnets?
Yes. It supports full IPv6 address expansion, zero-compression notation, and 64-bit/128-bit subnet boundary calculations.
Notes from this implementation
Parse the address before you subnet it
The page takes an IPv4 or IPv6 address and, when you pass a prefix length, shows the network and broadcast for v4. 192.168.1.10/24 is the network 192.168.1.0 with hosts .1 through .254. The /32 is a single host. The /0 is the whole space. Those two are the ones people paste by accident.
IPv6 prefixes do not have a broadcast address in the v4 sense. If the tool prints one for v6, that is a bug, not a fact. Leading zeros in v4 (192.168.001.010) are decimal here. Some old parsers treated them as octal. Do not rely on the leading zero meaning anything.
Nothing on this page contacts the address. The DNS page is the one that sends a name to a resolver, and it says so in its own note.