Subnet Calculator

IPv4 & IPv6 subnetting — forward, reverse, divider, VLSM, supernet and IPv6 analysis

IPv4
IPv6

Calculate network, broadcast, host range from IPv4 CIDR

IP / CIDR Input

Parsed: 192.168.1.0 / 24 (mask 255.255.255.0)

Quick examples

Binary View

IP Address

11000000.10101000.00000001.00000000

Subnet Mask

11111111.11111111.11111111.00000000

Network

11000000.10101000.00000001.00000000

Network (N) / Host (H) boundary

NNNNNNNNNNNNNNNNNNNNNNNNHHHHHHHH

Common Subnets Reference

CIDRMaskHostsClass
/8255.0.0.016,777,214A
/16255.255.0.065,534B
/24255.255.255.0254C
/25255.255.255.128126½C
/26255.255.255.19262¼C
/27255.255.255.22430C
/28255.255.255.24014C
/29255.255.255.2486C
/30255.255.255.2522P2P

Network Summary

Network

192.168.1.0/24

Usable Hosts

254

IP Class

Private

Network Details

Network Address
192.168.1.0
Broadcast Address
192.168.1.255
First Host
192.168.1.1
Last Host
192.168.1.254
Subnet Mask
255.255.255.0
CIDR Prefix
/24
Wildcard Mask
0.0.0.255
Hex Mask
0xFFFFFF00
Total Addresses
256
Usable Hosts
254
RFC / Scope
RFC 1918 (Private)

Fit Check

/24 → 254 usable hosts

You entered the network address directly

RFC 1918 private range — safe for internal use

Prefix ≤ /30 — supports at least 2 hosts

Important Notes

IPv4 RFC 1918

10.0.0.0/8, 172.16.0.0/12, 192.168.0.0/16 are private and not routable on the public Internet.

IPv6 Addressing

IPv6 uses 128-bit addresses. /64 is the standard subnet prefix; EUI-64 auto-configuration applies below /64.

CIDR & VLSM

Modern routing uses CIDR exclusively. Classful A/B/C is legacy. VLSM allocates efficiently by host need.