Subnet Mask Calculator
Calculate subnet masks, network addresses, broadcast addresses, and host ranges. Free online subnet calculator with CIDR notation support.
Subnet Calculator
How to Use Subnet Calculator
This tool calculates subnet information from IP address and subnet mask or CIDR notation:
- Network Address: The first address in the subnet
- Broadcast Address: The last address in the subnet
- Host Range: Usable IP addresses for devices
- CIDR Notation: Classless Inter-Domain Routing format
Enter an IP address and subnet mask (e.g., 255.255.255.0) or CIDR notation (e.g., /24) to get detailed subnet information.
Common Subnet Masks
| CIDR | Subnet Mask | Wildcard Mask | Total Hosts | Usable Hosts |
|---|---|---|---|---|
| /30 | 255.255.255.252 | 0.0.0.3 | 4 | 2 |
| /29 | 255.255.255.248 | 0.0.0.7 | 8 | 6 |
| /28 | 255.255.255.240 | 0.0.0.15 | 16 | 14 |
| /27 | 255.255.255.224 | 0.0.0.31 | 32 | 30 |
| /26 | 255.255.255.192 | 0.0.0.63 | 64 | 62 |
| /25 | 255.255.255.128 | 0.0.0.127 | 128 | 126 |
| /24 | 255.255.255.0 | 0.0.0.255 | 256 | 254 |
| /16 | 255.255.0.0 | 0.0.255.255 | 65,536 | 65,534 |
| /8 | 255.0.0.0 | 0.255.255.255 | 16,777,216 | 16,777,214 |