IP Subnet Calculator – IPv4 & IPv6 Explained
Use this free IP Subnet Calculator to find network address, broadcast address, usable host range, subnet mask, and more for IPv4 and IPv6. Supports CIDR and dot-decimal notation. Learn about subnetting, IP classes, and CIDR for efficient network management.
What is Subnetting?
- Subnetting divides a network into smaller, manageable sub-networks.
- Improves security, performance, and efficient IP address allocation.
- Uses subnet masks (IPv4) or prefix lengths (IPv6) to define network boundaries.
CIDR & IP Classes
- CIDR: Classless Inter-Domain Routing, uses /n notation (e.g., /24) for flexible subnetting.
- IP Classes: A (1.0.0.0–126.255.255.255), B (128.0.0.0–191.255.255.255), C (192.0.0.0–223.255.255.255).
IPv4 Subnet Table
| Prefix | Mask | Usable Hosts |
|---|
| /24 | 255.255.255.0 | 254 |
| /25 | 255.255.255.128 | 126 |
| /26 | 255.255.255.192 | 62 |
| /27 | 255.255.255.224 | 30 |
| /28 | 255.255.255.240 | 14 |
| /29 | 255.255.255.248 | 6 |
| /30 | 255.255.255.252 | 2 |