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IP Subnet Calculator
Calculate subnet details from CIDR notation: network/broadcast addresses, subnet mask, wildcard mask, host range, and usable host count. Runs entirely in your browser — your data never leaves your machine.
ip subnet cidr network calculator developer-tools
Published May 28, 2026
All interactive tools run entirely in your browser. Your data never leaves your device.
How It Works
Enter an IPv4 address with CIDR prefix length (e.g., 192.168.1.0/24). The tool instantly calculates all subnet details including network boundaries, host range, and address counts.
Results
| Field | Description |
|---|---|
| Network Address | First address in the subnet (network identifier) |
| Broadcast Address | Last address in the subnet (broadcast) |
| Subnet Mask | Dotted decimal mask (e.g., 255.255.255.0) |
| Wildcard Mask | Inverse of subnet mask (used in ACLs) |
| First/Last Host | Usable host address range |
| Usable Hosts | Number of addresses available for hosts |
| IP Class | Traditional classful network class (A-E) |
Common CIDR Blocks
| CIDR | Subnet Mask | Usable Hosts | Use Case |
|---|---|---|---|
| /8 | 255.0.0.0 | 16,777,214 | Class A networks |
| /16 | 255.255.0.0 | 65,534 | Class B networks |
| /24 | 255.255.255.0 | 254 | Class C / typical LAN |
| /28 | 255.255.255.240 | 14 | Small subnets |
| /30 | 255.255.255.252 | 2 | Point-to-point links |
| /32 | 255.255.255.255 | 1 | Single host route |
Features
- CIDR notation input with common presets
- Full subnet breakdown: network, broadcast, mask, host range
- Binary mask display for visual learning
- Copy all results with one click
- Private: runs entirely in the browser — no data transmitted