Hex Calculator

Subnet Calculator

Subnet Mask
Wildcard Mask
Network Address
Broadcast Address
First Usable
Last Usable
Total Hosts
Hex IP

This free subnet calculator derives the subnet mask, wildcard mask, network address, broadcast address, usable host range, and host count for any IPv4 address and CIDR prefix — with every key value also shown in hexadecimal.

How Subnetting Works

A subnet mask defines which bits of an IP address identify the network and which identify the host. With CIDR notation, the prefix number tells you how many leading bits belong to the network portion — a /24 prefix means the first 24 bits are the network.

For 192.168.1.0/24, the subnet mask is 255.255.255.0, the network address is 192.168.1.0, and the broadcast address is 192.168.1.255. The usable host range runs from 192.168.1.1 to 192.168.1.254, giving 254 usable addresses.

  • The CIDR prefix is the count of network bits, from 0 to 32.
  • The subnet mask has ones in the network bits and zeros in the host bits.
  • The wildcard mask is the bitwise inverse of the subnet mask.
  • The network address has all host bits zeroed; broadcast has them all set.
  • First and last usable addresses are one past network and one before broadcast.

Why Show Subnet Values in Hex?

IPv4 addresses and masks are just 32-bit numbers, and hexadecimal is a compact way to express them. The network address 192.168.1.0, for instance, appears as 0xC0A80100 in hex — the same value you might see in routing tables or packet dumps.

Seeing both notations helps you connect dotted-decimal IPs to the hex forms used in low-level networking tools.