IPv4 Tools

Subnet calculator, IP analyser, CIDR host list, integer conversion, network splitter and private range reference

IP Analyser

Subnet Calculator

Host List

Conversions

Subnet Splitter

Private Ranges

IP Address Analyser

Enter any IPv4 address (optionally with CIDR prefix) to get a full breakdown.

IPv4 Address (with optional /prefix)

Subnet Calculator

Network / IP Address

Prefix length or Subnet Mask

Host List Generator

Generates all IP addresses within a CIDR block. Limited to /16 (65,536 addresses) to keep the browser responsive.

CIDR Notation

IP ↔ Integer ↔ Hex ↔ Binary

IPv4 Address (dotted decimal)

Integer (32-bit)

Hexadecimal

Results

Subnet Mask ↔ CIDR Prefix

Subnet Mask (dotted)

Prefix Length

Reverse DNS (PTR)

IPv4 Address

Subnet Splitter

Divide a network into equal smaller subnets.

Network (CIDR)

New Prefix Length

IPv4 Special & Private Address Ranges

CIDR Range	Description	RFC	Type	Hosts
10.0.0.0/8	Private network (Class A)	RFC 1918	Private	16,777,214
172.16.0.0/12	Private network (Class B range)	RFC 1918	Private	1,048,574
192.168.0.0/16	Private network (Class C range)	RFC 1918	Private	65,534
127.0.0.0/8	Loopback (localhost)	RFC 5735	Loopback	16,777,214
169.254.0.0/16	Link-local / APIPA (auto-assigned)	RFC 3927	Link-local	65,534
0.0.0.0/8	Current network (this host on this network)	RFC 1122	Reserved	—
100.64.0.0/10	Shared address space (ISP/carrier NAT)	RFC 6598	Shared	4,194,302
192.0.0.0/24	IETF Protocol Assignments	RFC 6890	Reserved	254
192.0.2.0/24	TEST-NET-1 (documentation)	RFC 5737	Docs	254
198.51.100.0/24	TEST-NET-2 (documentation)	RFC 5737	Docs	254
203.0.113.0/24	TEST-NET-3 (documentation)	RFC 5737	Docs	254
192.88.99.0/24	6to4 Relay Anycast (deprecated)	RFC 7526	Deprecated	254
198.18.0.0/15	Benchmarking / network testing	RFC 2544	Benchmark	131,070
224.0.0.0/4	Multicast addresses	RFC 3171	Multicast	268,435,456
240.0.0.0/4	Reserved for future use (Class E)	RFC 1112	Reserved	268,435,455
255.255.255.255/32	Limited broadcast	RFC 919	Broadcast	1

IPv4 Address Classes (Classful)

Class	First Octet	Default Mask	Networks	Hosts/Network	Use
Class A	1 – 126	/8 (255.0.0.0)	126	16,777,214	Large organisations
Class B	128 – 191	/16 (255.255.0.0)	16,384	65,534	Medium organisations
Class C	192 – 223	/24 (255.255.255.0)	2,097,152	254	Small networks
Class D	224 – 239	N/A	N/A	N/A	Multicast
Class E	240 – 255	N/A	N/A	N/A	Experimental / Reserved

Common CIDR Prefix Reference

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