IP Subnet Calculator

Enter an IP address with CIDR notation or subnet mask. Get network details, host range, and format conversions instantly.

IP Address

CIDR

Or enter subnet mask:

Subnet Details

Network Address —

Broadcast Address —

First Host —

Last Host —

Total Hosts —

Usable Hosts —

Subnet Mask —

Wildcard Mask —

CIDR Notation —

IP Class —

IP Type —

IP Format Conversions

Decimal —

Binary —

Hexadecimal —

Integer —

IPv4-Mapped IPv6 —

CIDR Quick Reference

CIDR	Subnet Mask	Total IPs	Usable Hosts

How Subnetting Works

Subnetting divides a network into smaller segments. The subnet mask determines which bits of an IP address identify the network and which identify the host. A /24 network uses 24 bits for the network portion, leaving 8 bits (256 addresses, 254 usable) for hosts.

Key Concepts

Network address — the first address in a subnet, identifies the network itself
Broadcast address — the last address, used to reach all hosts on the subnet
CIDR notation — shorthand like /24, indicating the number of network bits in the mask
Wildcard mask — the inverse of the subnet mask, used in ACLs and routing configs
Usable hosts — total addresses minus the network and broadcast addresses

Private IP Ranges

Class A — 10.0.0.0 to 10.255.255.255 (/8)
Class B — 172.16.0.0 to 172.31.255.255 (/12)
Class C — 192.168.0.0 to 192.168.255.255 (/16)

Privacy

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