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IP subnet calculator

Type an address with its prefix or mask to see the network, its usable range and masks. Split it into smaller subnets, or look up any prefix in the reference tables.

Network231.192.4.0/22
Usable hosts1,022
Subnet mask255.255.252.0
Addresses1,024
Network address
231.192.4.0
Broadcast address
231.192.7.255
First usable
231.192.4.1
Last usable
231.192.7.254
Usable hosts
1,022 (1,024 less the network and broadcast addresses)
Subnet mask
255.255.252.0
Wildcard mask
0.0.3.255 (Cisco ACLs, OSPF)
Prefix length
/22
Type
Multicast 224.0.0.0/4
One-to-many traffic, such as IPTV and routing protocols
Old class
D (multicast)
As numbers
Hex E7C00400 · Integer 3888120832 to 3888121855
Reverse DNS zones
4.192.231.in-addr.arpa
5.192.231.in-addr.arpa
6.192.231.in-addr.arpa
7.192.231.in-addr.arpa
/22 is not on a 8-bit boundary, so it takes 4 /24 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address11100111.11000000.00000100.00000000231.192.4.0
Subnet mask11111111.11111111.11111100.00000000255.255.252.0
Network11100111.11000000.00000100.00000000231.192.4.0
Broadcast11100111.11000000.00000111.11111111231.192.7.255
Split into smaller subnets/29
/23 (2)/24 (4)/25 (8)/26 (16)/27 (32)/28 (64)/29 (128)/30 (256)/31 (512)/32 (1,024)

231.192.4.0/22 makes 128 subnets of /29.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1231.192.4.0/29231.192.4.1 to 231.192.4.6231.192.4.76
2231.192.4.8/29231.192.4.9 to 231.192.4.14231.192.4.156
3231.192.4.16/29231.192.4.17 to 231.192.4.22231.192.4.236
4231.192.4.24/29231.192.4.25 to 231.192.4.30231.192.4.316
5231.192.4.32/29231.192.4.33 to 231.192.4.38231.192.4.396
6231.192.4.40/29231.192.4.41 to 231.192.4.46231.192.4.476
7231.192.4.48/29231.192.4.49 to 231.192.4.54231.192.4.556
8231.192.4.56/29231.192.4.57 to 231.192.4.62231.192.4.636
9231.192.4.64/29231.192.4.65 to 231.192.4.70231.192.4.716
10231.192.4.72/29231.192.4.73 to 231.192.4.78231.192.4.796
11231.192.4.80/29231.192.4.81 to 231.192.4.86231.192.4.876
12231.192.4.88/29231.192.4.89 to 231.192.4.94231.192.4.956
13231.192.4.96/29231.192.4.97 to 231.192.4.102231.192.4.1036
14231.192.4.104/29231.192.4.105 to 231.192.4.110231.192.4.1116
15231.192.4.112/29231.192.4.113 to 231.192.4.118231.192.4.1196
16231.192.4.120/29231.192.4.121 to 231.192.4.126231.192.4.1276
17231.192.4.128/29231.192.4.129 to 231.192.4.134231.192.4.1356
18231.192.4.136/29231.192.4.137 to 231.192.4.142231.192.4.1436
19231.192.4.144/29231.192.4.145 to 231.192.4.150231.192.4.1516
20231.192.4.152/29231.192.4.153 to 231.192.4.158231.192.4.1596
21231.192.4.160/29231.192.4.161 to 231.192.4.166231.192.4.1676
22231.192.4.168/29231.192.4.169 to 231.192.4.174231.192.4.1756
23231.192.4.176/29231.192.4.177 to 231.192.4.182231.192.4.1836
24231.192.4.184/29231.192.4.185 to 231.192.4.190231.192.4.1916
25231.192.4.192/29231.192.4.193 to 231.192.4.198231.192.4.1996
26231.192.4.200/29231.192.4.201 to 231.192.4.206231.192.4.2076
27231.192.4.208/29231.192.4.209 to 231.192.4.214231.192.4.2156
28231.192.4.216/29231.192.4.217 to 231.192.4.222231.192.4.2236
29231.192.4.224/29231.192.4.225 to 231.192.4.230231.192.4.2316
30231.192.4.232/29231.192.4.233 to 231.192.4.238231.192.4.2396
31231.192.4.240/29231.192.4.241 to 231.192.4.246231.192.4.2476
32231.192.4.248/29231.192.4.249 to 231.192.4.254231.192.4.2556
33231.192.5.0/29231.192.5.1 to 231.192.5.6231.192.5.76
34231.192.5.8/29231.192.5.9 to 231.192.5.14231.192.5.156
35231.192.5.16/29231.192.5.17 to 231.192.5.22231.192.5.236
36231.192.5.24/29231.192.5.25 to 231.192.5.30231.192.5.316
37231.192.5.32/29231.192.5.33 to 231.192.5.38231.192.5.396
38231.192.5.40/29231.192.5.41 to 231.192.5.46231.192.5.476
39231.192.5.48/29231.192.5.49 to 231.192.5.54231.192.5.556
40231.192.5.56/29231.192.5.57 to 231.192.5.62231.192.5.636
41231.192.5.64/29231.192.5.65 to 231.192.5.70231.192.5.716
42231.192.5.72/29231.192.5.73 to 231.192.5.78231.192.5.796
43231.192.5.80/29231.192.5.81 to 231.192.5.86231.192.5.876
44231.192.5.88/29231.192.5.89 to 231.192.5.94231.192.5.956
45231.192.5.96/29231.192.5.97 to 231.192.5.102231.192.5.1036
46231.192.5.104/29231.192.5.105 to 231.192.5.110231.192.5.1116
47231.192.5.112/29231.192.5.113 to 231.192.5.118231.192.5.1196
48231.192.5.120/29231.192.5.121 to 231.192.5.126231.192.5.1276
49231.192.5.128/29231.192.5.129 to 231.192.5.134231.192.5.1356
50231.192.5.136/29231.192.5.137 to 231.192.5.142231.192.5.1436
51231.192.5.144/29231.192.5.145 to 231.192.5.150231.192.5.1516
52231.192.5.152/29231.192.5.153 to 231.192.5.158231.192.5.1596
53231.192.5.160/29231.192.5.161 to 231.192.5.166231.192.5.1676
54231.192.5.168/29231.192.5.169 to 231.192.5.174231.192.5.1756
55231.192.5.176/29231.192.5.177 to 231.192.5.182231.192.5.1836
56231.192.5.184/29231.192.5.185 to 231.192.5.190231.192.5.1916
57231.192.5.192/29231.192.5.193 to 231.192.5.198231.192.5.1996
58231.192.5.200/29231.192.5.201 to 231.192.5.206231.192.5.2076
59231.192.5.208/29231.192.5.209 to 231.192.5.214231.192.5.2156
60231.192.5.216/29231.192.5.217 to 231.192.5.222231.192.5.2236
61231.192.5.224/29231.192.5.225 to 231.192.5.230231.192.5.2316
62231.192.5.232/29231.192.5.233 to 231.192.5.238231.192.5.2396
63231.192.5.240/29231.192.5.241 to 231.192.5.246231.192.5.2476
64231.192.5.248/29231.192.5.249 to 231.192.5.254231.192.5.2556
65231.192.6.0/29231.192.6.1 to 231.192.6.6231.192.6.76
66231.192.6.8/29231.192.6.9 to 231.192.6.14231.192.6.156
67231.192.6.16/29231.192.6.17 to 231.192.6.22231.192.6.236
68231.192.6.24/29231.192.6.25 to 231.192.6.30231.192.6.316
69231.192.6.32/29231.192.6.33 to 231.192.6.38231.192.6.396
70231.192.6.40/29231.192.6.41 to 231.192.6.46231.192.6.476
71231.192.6.48/29231.192.6.49 to 231.192.6.54231.192.6.556
72231.192.6.56/29231.192.6.57 to 231.192.6.62231.192.6.636
73231.192.6.64/29231.192.6.65 to 231.192.6.70231.192.6.716
74231.192.6.72/29231.192.6.73 to 231.192.6.78231.192.6.796
75231.192.6.80/29231.192.6.81 to 231.192.6.86231.192.6.876
76231.192.6.88/29231.192.6.89 to 231.192.6.94231.192.6.956
77231.192.6.96/29231.192.6.97 to 231.192.6.102231.192.6.1036
78231.192.6.104/29231.192.6.105 to 231.192.6.110231.192.6.1116
79231.192.6.112/29231.192.6.113 to 231.192.6.118231.192.6.1196
80231.192.6.120/29231.192.6.121 to 231.192.6.126231.192.6.1276
81231.192.6.128/29231.192.6.129 to 231.192.6.134231.192.6.1356
82231.192.6.136/29231.192.6.137 to 231.192.6.142231.192.6.1436
83231.192.6.144/29231.192.6.145 to 231.192.6.150231.192.6.1516
84231.192.6.152/29231.192.6.153 to 231.192.6.158231.192.6.1596
85231.192.6.160/29231.192.6.161 to 231.192.6.166231.192.6.1676
86231.192.6.168/29231.192.6.169 to 231.192.6.174231.192.6.1756
87231.192.6.176/29231.192.6.177 to 231.192.6.182231.192.6.1836
88231.192.6.184/29231.192.6.185 to 231.192.6.190231.192.6.1916
89231.192.6.192/29231.192.6.193 to 231.192.6.198231.192.6.1996
90231.192.6.200/29231.192.6.201 to 231.192.6.206231.192.6.2076
91231.192.6.208/29231.192.6.209 to 231.192.6.214231.192.6.2156
92231.192.6.216/29231.192.6.217 to 231.192.6.222231.192.6.2236
93231.192.6.224/29231.192.6.225 to 231.192.6.230231.192.6.2316
94231.192.6.232/29231.192.6.233 to 231.192.6.238231.192.6.2396
95231.192.6.240/29231.192.6.241 to 231.192.6.246231.192.6.2476
96231.192.6.248/29231.192.6.249 to 231.192.6.254231.192.6.2556
97231.192.7.0/29231.192.7.1 to 231.192.7.6231.192.7.76
98231.192.7.8/29231.192.7.9 to 231.192.7.14231.192.7.156
99231.192.7.16/29231.192.7.17 to 231.192.7.22231.192.7.236
100231.192.7.24/29231.192.7.25 to 231.192.7.30231.192.7.316
101231.192.7.32/29231.192.7.33 to 231.192.7.38231.192.7.396
102231.192.7.40/29231.192.7.41 to 231.192.7.46231.192.7.476
103231.192.7.48/29231.192.7.49 to 231.192.7.54231.192.7.556
104231.192.7.56/29231.192.7.57 to 231.192.7.62231.192.7.636
105231.192.7.64/29231.192.7.65 to 231.192.7.70231.192.7.716
106231.192.7.72/29231.192.7.73 to 231.192.7.78231.192.7.796
107231.192.7.80/29231.192.7.81 to 231.192.7.86231.192.7.876
108231.192.7.88/29231.192.7.89 to 231.192.7.94231.192.7.956
109231.192.7.96/29231.192.7.97 to 231.192.7.102231.192.7.1036
110231.192.7.104/29231.192.7.105 to 231.192.7.110231.192.7.1116
111231.192.7.112/29231.192.7.113 to 231.192.7.118231.192.7.1196
112231.192.7.120/29231.192.7.121 to 231.192.7.126231.192.7.1276
113231.192.7.128/29231.192.7.129 to 231.192.7.134231.192.7.1356
114231.192.7.136/29231.192.7.137 to 231.192.7.142231.192.7.1436
115231.192.7.144/29231.192.7.145 to 231.192.7.150231.192.7.1516
116231.192.7.152/29231.192.7.153 to 231.192.7.158231.192.7.1596
117231.192.7.160/29231.192.7.161 to 231.192.7.166231.192.7.1676
118231.192.7.168/29231.192.7.169 to 231.192.7.174231.192.7.1756
119231.192.7.176/29231.192.7.177 to 231.192.7.182231.192.7.1836
120231.192.7.184/29231.192.7.185 to 231.192.7.190231.192.7.1916
121231.192.7.192/29231.192.7.193 to 231.192.7.198231.192.7.1996
122231.192.7.200/29231.192.7.201 to 231.192.7.206231.192.7.2076
123231.192.7.208/29231.192.7.209 to 231.192.7.214231.192.7.2156
124231.192.7.216/29231.192.7.217 to 231.192.7.222231.192.7.2236
125231.192.7.224/29231.192.7.225 to 231.192.7.230231.192.7.2316
126231.192.7.232/29231.192.7.233 to 231.192.7.238231.192.7.2396
127231.192.7.240/29231.192.7.241 to 231.192.7.246231.192.7.2476
128231.192.7.248/29231.192.7.249 to 231.192.7.254231.192.7.2556

IPv4 CIDR reference (/0 to /32)

IPv4 prefix lengths
PrefixSubnet maskWildcardAddressesUsable hostsSizeTypical use
/00.0.0.0255.255.255.2554,294,967,2964,294,967,29416,777,216 × /24
/1128.0.0.0127.255.255.2552,147,483,6482,147,483,6468,388,608 × /24
/2192.0.0.063.255.255.2551,073,741,8241,073,741,8224,194,304 × /24
/3224.0.0.031.255.255.255536,870,912536,870,9102,097,152 × /24
/4240.0.0.015.255.255.255268,435,456268,435,4541,048,576 × /24
/5248.0.0.07.255.255.255134,217,728134,217,726524,288 × /24
/6252.0.0.03.255.255.25567,108,86467,108,862262,144 × /24
/7254.0.0.01.255.255.25533,554,43233,554,430131,072 × /24
/8255.0.0.00.255.255.25516,777,21616,777,21465,536 × /24Old class A; 10.0.0.0/8
/9255.128.0.00.127.255.2558,388,6088,388,60632,768 × /24
/10255.192.0.00.63.255.2554,194,3044,194,30216,384 × /24
/11255.224.0.00.31.255.2552,097,1522,097,1508,192 × /24
/12255.240.0.00.15.255.2551,048,5761,048,5744,096 × /24172.16.0.0/12
/13255.248.0.00.7.255.255524,288524,2862,048 × /24
/14255.252.0.00.3.255.255262,144262,1421,024 × /24
/15255.254.0.00.1.255.255131,072131,070512 × /24
/16255.255.0.00.0.255.25565,53665,534256 × /24Old class B; 192.168.0.0/16
/17255.255.128.00.0.127.25532,76832,766128 × /24
/18255.255.192.00.0.63.25516,38416,38264 × /24
/19255.255.224.00.0.31.2558,1928,19032 × /24
/20255.255.240.00.0.15.2554,0964,09416 × /24
/21255.255.248.00.0.7.2552,0482,0468 × /24
/22255.255.252.00.0.3.2551,0241,0224 × /24Large office or guest Wi-Fi (1,022 hosts)
/23255.255.254.00.0.1.2555125102 × /24Larger office LAN (510 hosts)
/24255.255.255.00.0.0.2552562541 × /24Typical office LAN (old class C)
/25255.255.255.1280.0.0.1271281261/2 of a /24Smaller LAN or VLAN
/26255.255.255.1920.0.0.6364621/4 of a /24Smaller LAN or VLAN
/27255.255.255.2240.0.0.3132301/8 of a /24Small VLAN, phones, cameras
/28255.255.255.2400.0.0.1516141/16 of a /24Small VLAN, phones, cameras
/29255.255.255.2480.0.0.7861/32 of a /24Small fixed public block (5 usable)
/30255.255.255.2520.0.0.3421/64 of a /24Point-to-point (old style)
/31255.255.255.2540.0.0.1221/128 of a /24Point-to-point link (RFC 3021)
/32255.255.255.2550.0.0.0111/256 of a /24One host

IPv6 prefix reference

IPv6 prefix lengths
PrefixAddresses/64 LANs/48 sitesNibbleTypical use
/342,535,295,865,117,307,932,921,825,928,971,026,432 (2^125)2,305,843,009,213,693,95235,184,372,088,832NoAll global unicast (2000::/3)
/165,192,296,858,534,827,628,530,496,329,220,096 (2^112)281,474,976,710,6564,294,967,296Yes
/20324,518,553,658,426,726,783,156,020,576,256 (2^108)17,592,186,044,416268,435,456YesLarge provider allocation (RIPE minimum for some)
/29633,825,300,114,114,700,748,351,602,688 (2^99)34,359,738,368524,288NoRIPE allocation to a provider (often)
/3279,228,162,514,264,337,593,543,950,336 (2^96)4,294,967,29665,536YesProvider allocation (RIPE default)
/364,951,760,157,141,521,099,596,496,896 (2^92)268,435,4564,096Yes
/40309,485,009,821,345,068,724,781,056 (2^88)16,777,216256Yes
/4419,342,813,113,834,066,795,298,816 (2^84)1,048,57616Yes
/481,208,925,819,614,629,174,706,176 (2^80)65,5361YesOne site or organisation (RIPE PI / assignment)
/5275,557,863,725,914,323,419,136 (2^76)4,096Yes
/564,722,366,482,869,645,213,696 (2^72)256YesSmall site or home (common provider assignment)
/60295,147,905,179,352,825,856 (2^68)16YesSome home broadband (16 LANs)
/6418,446,744,073,709,551,616 (2^64)1YesOne LAN or VLAN (needed for SLAAC)
/7272,057,594,037,927,936 (2^56)1/256 of a /64Yes
/80281,474,976,710,656 (2^48)1/65,536 of a /64Yes
/964,294,967,2961/4,294,967,296 of a /64YesEmbeds an IPv4 address (NAT64)
/11265,5361/281,474,976,710,656 of a /64Yes
/1202561/72,057,594,037,927,936 of a /64Yes
/124161/1,152,921,504,606,846,976 of a /64Yes
/12641/4,611,686,018,427,387,904 of a /64No
/12721/9,223,372,036,854,775,808 of a /64NoPoint-to-point link (RFC 6164)
/12811/18,446,744,073,709,551,616 of a /64YesOne host or loopback

Private and special ranges

IPv4

Special-purpose ranges
RangeNameWhat it is
255.255.255.255/32Limited broadcastEvery host on the local network
0.0.0.0/8This networkNot routed; 0.0.0.0 means "any address" in settings
10.0.0.0/8Private (RFC 1918)Office and home networks; not routed on the internet
100.64.0.0/10Shared address space (CGNAT)Used by providers behind carrier-grade NAT (RFC 6598)
127.0.0.0/8LoopbackThis computer
169.254.0.0/16Link-local (APIPA)Self-assigned when no DHCP server answers
172.16.0.0/12Private (RFC 1918)Office and home networks; not routed on the internet
192.0.0.0/24IETF protocol assignmentsSpecial uses such as DS-Lite
192.0.2.0/24Documentation (TEST-NET-1)For examples; never used on a network
192.88.99.0/246to4 relay (deprecated)Formerly anycast for 6to4
192.168.0.0/16Private (RFC 1918)Office and home networks; not routed on the internet
198.18.0.0/15BenchmarkingNetwork equipment testing (RFC 2544)
198.51.100.0/24Documentation (TEST-NET-2)For examples; never used on a network
203.0.113.0/24Documentation (TEST-NET-3)For examples; never used on a network
224.0.0.0/4MulticastOne-to-many traffic, such as IPTV and routing protocols
240.0.0.0/4ReservedFuture use; not usable on most systems

IPv6

Special-purpose ranges
RangeNameWhat it is
::/128UnspecifiedNo address; :: means "any address" in settings
::1/128LoopbackThis computer
::ffff:0:0/96IPv4-mappedAn IPv4 address written as IPv6
64:ff9b::/96NAT64IPv4 addresses reached through a NAT64 gateway
100::/64Discard onlyTraffic sent here is dropped (RFC 6666)
2001:db8::/32DocumentationFor examples; never used on a network
2001::/32TeredoIPv6 tunnelled over IPv4 UDP
2002::/166to4IPv6 tunnelled over IPv4 (largely retired)
3fff::/20DocumentationFor examples (RFC 9637)
fc00::/7Unique local (ULA)Private IPv6, like RFC 1918; usually fd00::/8
fe80::/10Link-localEvery IPv6 interface has one; not routed
ff00::/8MulticastOne-to-many traffic; replaces broadcast
2000::/3Global unicastPublic internet addresses

About this tool

A network is written as an address and a prefix length, such as 192.168.1.0/24: the first 24 bits name the network and the rest number the devices on it. The calculator works out where the network starts and ends, how many devices it holds, its subnet and wildcard masks, and the reverse DNS zone to ask your provider for.

It also splits a network into equal smaller ones (one per VLAN or site), turns a range of addresses into the fewest CIDR blocks for a firewall rule, and lists every IPv4 prefix length and the common IPv6 ones in reference tables.

Common questions

Why are two addresses lost in every IPv4 subnet?

The first address names the network and the last is the broadcast address, so a /24 has 256 addresses but 254 for devices. A /31 (a link between two routers) and a /32 (one host) are the exceptions.

What size of IPv6 network should a LAN use?

Always /64. Devices pick their own address within it (SLAAC), which needs the full 64 bits. A site usually gets a /48 or /56 from its provider, which holds 65,536 or 256 LANs.

What is a wildcard mask?

The subnet mask turned inside out: 255.255.255.0 becomes 0.0.0.255. Cisco access lists and OSPF use it to say which bits must match.

Which ranges can I use inside an office?

IPv4: 10.0.0.0/8, 172.16.0.0/12 and 192.168.0.0/16. IPv6: unique local addresses from fd00::/8, though most networks use the public prefix from their provider.