IP Subnet Calculator
Calculate subnet masks, network ranges, host counts, and binary representations for IPv4 addresses
Enter an IP address with CIDR prefix (e.g. 192.168.1.0/24)
Network Information
CIDR Prefix /24
Address Details
What is IP Subnet Calculator?
An IP subnet calculator takes an IPv4 address and a subnet mask (in CIDR or dotted-decimal notation) and computes all the derived network information you need for network design, troubleshooting, and documentation. Subnetting divides a large IP address space into smaller logical networks, improving security, performance, and manageability.
Enter an address such as 192.168.1.50/24 and the tool instantly returns the network address, broadcast address, first and last usable host addresses, total number of hosts, subnet mask in dotted-decimal and binary, wildcard mask, and the IP class. Binary representation is shown for every field so students and network engineers can visualise exactly how the host and network portions of the address are separated by the prefix length.
Subnet calculators are indispensable for network administrators planning VLAN segmentation, firewall rules, and routing table entries. They are equally useful for students preparing for CCNA, Network+, or other networking certifications where subnetting is a core skill. Rather than working through binary conversions by hand or using error-prone mental arithmetic, this tool gives you verified results in milliseconds.
How to Use IP Subnet Calculator
- Enter an IP address
Type any valid IPv4 address in dotted-decimal format, for example 192.168.10.1.
- Specify a subnet mask
Enter the prefix length in CIDR notation (for example /24) or a dotted-decimal subnet mask (for example 255.255.255.0).
- Review the results
See network address, broadcast address, host range, total hosts, and binary representations of every field.
- Copy or share
Copy individual values or the full summary to use in network diagrams, documentation, or configuration files.
Key Benefits
All subnet values are computed the moment you finish entering the address and mask — no waiting.
Every result is shown in both decimal and binary so you can see exactly how subnetting works at the bit level.
Network address, broadcast, host range, wildcard mask, IP class, and host count are all displayed together.
Use the calculator immediately without creating an account or sharing any personal information.
Frequently Asked Questions
CIDR (Classless Inter-Domain Routing) notation appends a slash and prefix length to an IP address, for example 10.0.0.0/8. The prefix length indicates how many bits are used for the network portion.
A /24 subnet has 256 addresses. Two are reserved (network and broadcast), leaving 254 usable host addresses.
A wildcard mask is the bitwise inverse of the subnet mask. It is used in Cisco ACLs and OSPF configuration to specify which bits to match or ignore.
Yes. A /30 has 4 addresses (2 usable) and is common for point-to-point links. A /31 is used for point-to-point links per RFC 3021 and has no broadcast address.