Free IPv4 Subnet Calculator — CIDR, Subnet Mask & Network Planning Tool Subnetlab.com
IPv4 Subnet Calculator
Enter a valid IPv4 address
Enter subnet mask or CIDR notation
Network Information
Network Address:
-
Broadcast Address:
-
First Usable IP:
-
Last Usable IP:
-
Subnet Details
Usable Hosts:
-
Wildcard Mask:
-
CIDR Notation:
-
IP Class:
-
Subnet Mask Details
Subnet Mask (Decimal):
-
Subnet Mask (Binary):
-
IPv4 Class Reference
| Class | Range | Default Subnet Mask |
|---|---|---|
| A | 1.0.0.0 – 126.255.255.255 | 255.0.0.0 |
| B | 128.0.0.0 – 191.255.255.255 | 255.255.0.0 |
| C | 192.0.0.0 – 223.255.255.255 | 255.255.255.0 |
| D | 224.0.0.0 – 239.255.255.255 | Reserved (Multicast) |
| E | 240.0.0.0 – 255.255.255.255 | Reserved (Experimental) |
"Fast, accurate IPv4 subnetting for network engineers and students. The tool handles classful and classless addressing. For a deeper breakdown of subnet masks, wildcard bits, and usable hosts, check out the full article."
Network Tools
IPv4 Tools
Network Utilities
Number Conversions