IPv4 & CIDR Subnet Calculator

Instant network calculations, host ranges, wildcard masks, and binary bit breakdowns.

100% Client-Side • Zero Telemetry
Presets:
Network Address (CIDR)
192.168.1.0/24
Usable Host Range
192.168.1.1 – 192.168.1.254
Broadcast Address
192.168.1.255
Subnet Mask
255.255.255.0
Wildcard Mask
0.0.0.255
Usable Hosts / Total Addresses
254 usable (256 total)
IP Type & Scope
Private Internet (RFC 1918)
Hexadecimal & Integer
0xC0A80101 • 3232235777

Binary Breakdown ■ Network Bits   ■ Host Bits

IP Address: 11000000.10101000.00000001.00000001
Subnet Mask: 11111111.11111111.11111111.00000000
Network: 11000000.10101000.00000001.00000000

How CIDR Subnetting Works

Classless Inter-Domain Routing (CIDR) replaced the historical classful network system (Class A, B, C) in 1993 to allocate IP addresses more efficiently. The suffix (e.g. /24) represents the number of contiguous leading bits assigned to the Network ID, leaving the remaining bits (32 - prefix) to uniquely address individual Hosts.

Usable Hosts Formula:

2(32 - prefix) - 2

(Minus 2 for Network ID & Broadcast address; /31 and /32 are special cases).
RFC 1918 Private Ranges:
  • 10.0.0.0 – 10.255.255.255 (/8)
  • 172.16.0.0 – 172.31.255.255 (/12)
  • 192.168.0.0 – 192.168.255.255 (/16)