IP Subnet Calculator
Calculate network addresses, host ranges, broadcast, and subnet splits for any IPv4 CIDR block.
Input
Results
| IP Address | 192.168.1.0 |
| Network Address | 192.168.1.0 |
| Broadcast Address | 192.168.1.255 |
| First Usable Host | 192.168.1.1 |
| Last Usable Host | 192.168.1.254 |
| Usable Hosts | 254 |
| Subnet Mask | 255.255.255.0 |
| Wildcard Mask | 0.0.0.255 |
| CIDR Notation | 192.168.1.0/24 |
| IP Class | Class C |
| IP Type | Private (Class C) |
| Total Addresses | 256 |
Binary Visualizer
Subnet Splitter
| # | Network | First Host | Last Host | Broadcast |
|---|---|---|---|---|
| 1 | 192.168.1.0/25 | 192.168.1.1 | 192.168.1.126 | 192.168.1.127 |
| 2 | 192.168.1.128/25 | 192.168.1.129 | 192.168.1.254 | 192.168.1.255 |
IP subnet calculator online: CIDR subnetting with host ranges and binary breakdown
Subnetting is a fundamental networking skill, but manually calculating network addresses, broadcast addresses, and host ranges from CIDR notation is error-prone and slow. This tool does it instantly: enter any IPv4 address in CIDR notation and get a complete breakdown of the subnet including the network address, broadcast address, usable host range, subnet mask, wildcard mask, and the binary representation of each value.
Whether you are designing a network architecture, configuring firewall rules, studying for a networking certification, or debugging a connectivity issue, this calculator gives you every number you need in one view.
Step-by-step guide
- 1Enter an IP address and prefix length
Type an IPv4 address with CIDR notation (e.g. 192.168.1.0/24) or enter the IP and subnet mask separately. - 2View network address
The calculator shows the network address: the base address of the subnet with all host bits set to zero. - 3Check the broadcast address
The broadcast address is shown: the highest address in the subnet, used to send packets to all hosts on the network. - 4See the usable host range
The first and last usable host IP addresses are displayed, along with the total number of usable hosts in the subnet. - 5Inspect binary representations
The binary breakdown of the IP address and subnet mask is shown, making it easy to see the network and host portions visually.
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Frequently Asked Questions
- What is a subnet?
- A subnet (subnetwork) is a logical subdivision of an IP network. Subnetting divides a larger network into smaller segments to improve performance, security, and manageability.
- What is CIDR notation?
- CIDR (Classless Inter-Domain Routing) notation expresses an IP address and its associated network prefix length in one string, for example 192.168.1.0/24. The /24 indicates that the first 24 bits are the network portion.
- What is the difference between the network address and the broadcast address?
- The network address is the first address in a subnet (all host bits zero) and identifies the subnet itself. The broadcast address is the last address (all host bits one) and is used to address all hosts in the subnet simultaneously.
- How many usable hosts does a /24 subnet have?
- A /24 subnet has 256 total addresses. Subtracting the network address and broadcast address leaves 254 usable host addresses.
- What is the formula for the number of usable hosts?
- The number of usable hosts is 2^(32 - prefix_length) - 2. The minus 2 accounts for the network and broadcast addresses which cannot be assigned to hosts.
- What is a wildcard mask?
- A wildcard mask is the bitwise inverse of a subnet mask. It is used in Cisco ACLs and OSPF configurations. For a /24 subnet mask of 255.255.255.0, the wildcard mask is 0.0.0.255.
- Can I calculate subnets for IPv6?
- This calculator focuses on IPv4 subnetting. IPv6 subnetting follows the same CIDR principles but uses 128-bit addresses.
- Is this tool free?
- Yes, completely free with no account, no sign-up, and no usage limits.
- Does this tool work offline?
- All calculations run in your browser using JavaScript, so once the page is loaded you can use it without an internet connection.
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