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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.

Network192.168.164.0/22
Usable hosts1,022
Subnet mask255.255.252.0
Addresses1,024
Network address
192.168.164.0
Broadcast address
192.168.167.255
First usable
192.168.164.1
Last usable
192.168.167.254
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
Private (RFC 1918) 192.168.0.0/16
Office and home networks; not routed on the internet
Old class
C (default /24)
As numbers
Hex C0A8A400 · Integer 3232277504 to 3232278527
Reverse DNS zones
164.168.192.in-addr.arpa
165.168.192.in-addr.arpa
166.168.192.in-addr.arpa
167.168.192.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
Address11000000.10101000.10100100.00000000192.168.164.0
Subnet mask11111111.11111111.11111100.00000000255.255.252.0
Network11000000.10101000.10100100.00000000192.168.164.0
Broadcast11000000.10101000.10100111.11111111192.168.167.255
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)

192.168.164.0/22 makes 128 subnets of /29.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1192.168.164.0/29192.168.164.1 to 192.168.164.6192.168.164.76
2192.168.164.8/29192.168.164.9 to 192.168.164.14192.168.164.156
3192.168.164.16/29192.168.164.17 to 192.168.164.22192.168.164.236
4192.168.164.24/29192.168.164.25 to 192.168.164.30192.168.164.316
5192.168.164.32/29192.168.164.33 to 192.168.164.38192.168.164.396
6192.168.164.40/29192.168.164.41 to 192.168.164.46192.168.164.476
7192.168.164.48/29192.168.164.49 to 192.168.164.54192.168.164.556
8192.168.164.56/29192.168.164.57 to 192.168.164.62192.168.164.636
9192.168.164.64/29192.168.164.65 to 192.168.164.70192.168.164.716
10192.168.164.72/29192.168.164.73 to 192.168.164.78192.168.164.796
11192.168.164.80/29192.168.164.81 to 192.168.164.86192.168.164.876
12192.168.164.88/29192.168.164.89 to 192.168.164.94192.168.164.956
13192.168.164.96/29192.168.164.97 to 192.168.164.102192.168.164.1036
14192.168.164.104/29192.168.164.105 to 192.168.164.110192.168.164.1116
15192.168.164.112/29192.168.164.113 to 192.168.164.118192.168.164.1196
16192.168.164.120/29192.168.164.121 to 192.168.164.126192.168.164.1276
17192.168.164.128/29192.168.164.129 to 192.168.164.134192.168.164.1356
18192.168.164.136/29192.168.164.137 to 192.168.164.142192.168.164.1436
19192.168.164.144/29192.168.164.145 to 192.168.164.150192.168.164.1516
20192.168.164.152/29192.168.164.153 to 192.168.164.158192.168.164.1596
21192.168.164.160/29192.168.164.161 to 192.168.164.166192.168.164.1676
22192.168.164.168/29192.168.164.169 to 192.168.164.174192.168.164.1756
23192.168.164.176/29192.168.164.177 to 192.168.164.182192.168.164.1836
24192.168.164.184/29192.168.164.185 to 192.168.164.190192.168.164.1916
25192.168.164.192/29192.168.164.193 to 192.168.164.198192.168.164.1996
26192.168.164.200/29192.168.164.201 to 192.168.164.206192.168.164.2076
27192.168.164.208/29192.168.164.209 to 192.168.164.214192.168.164.2156
28192.168.164.216/29192.168.164.217 to 192.168.164.222192.168.164.2236
29192.168.164.224/29192.168.164.225 to 192.168.164.230192.168.164.2316
30192.168.164.232/29192.168.164.233 to 192.168.164.238192.168.164.2396
31192.168.164.240/29192.168.164.241 to 192.168.164.246192.168.164.2476
32192.168.164.248/29192.168.164.249 to 192.168.164.254192.168.164.2556
33192.168.165.0/29192.168.165.1 to 192.168.165.6192.168.165.76
34192.168.165.8/29192.168.165.9 to 192.168.165.14192.168.165.156
35192.168.165.16/29192.168.165.17 to 192.168.165.22192.168.165.236
36192.168.165.24/29192.168.165.25 to 192.168.165.30192.168.165.316
37192.168.165.32/29192.168.165.33 to 192.168.165.38192.168.165.396
38192.168.165.40/29192.168.165.41 to 192.168.165.46192.168.165.476
39192.168.165.48/29192.168.165.49 to 192.168.165.54192.168.165.556
40192.168.165.56/29192.168.165.57 to 192.168.165.62192.168.165.636
41192.168.165.64/29192.168.165.65 to 192.168.165.70192.168.165.716
42192.168.165.72/29192.168.165.73 to 192.168.165.78192.168.165.796
43192.168.165.80/29192.168.165.81 to 192.168.165.86192.168.165.876
44192.168.165.88/29192.168.165.89 to 192.168.165.94192.168.165.956
45192.168.165.96/29192.168.165.97 to 192.168.165.102192.168.165.1036
46192.168.165.104/29192.168.165.105 to 192.168.165.110192.168.165.1116
47192.168.165.112/29192.168.165.113 to 192.168.165.118192.168.165.1196
48192.168.165.120/29192.168.165.121 to 192.168.165.126192.168.165.1276
49192.168.165.128/29192.168.165.129 to 192.168.165.134192.168.165.1356
50192.168.165.136/29192.168.165.137 to 192.168.165.142192.168.165.1436
51192.168.165.144/29192.168.165.145 to 192.168.165.150192.168.165.1516
52192.168.165.152/29192.168.165.153 to 192.168.165.158192.168.165.1596
53192.168.165.160/29192.168.165.161 to 192.168.165.166192.168.165.1676
54192.168.165.168/29192.168.165.169 to 192.168.165.174192.168.165.1756
55192.168.165.176/29192.168.165.177 to 192.168.165.182192.168.165.1836
56192.168.165.184/29192.168.165.185 to 192.168.165.190192.168.165.1916
57192.168.165.192/29192.168.165.193 to 192.168.165.198192.168.165.1996
58192.168.165.200/29192.168.165.201 to 192.168.165.206192.168.165.2076
59192.168.165.208/29192.168.165.209 to 192.168.165.214192.168.165.2156
60192.168.165.216/29192.168.165.217 to 192.168.165.222192.168.165.2236
61192.168.165.224/29192.168.165.225 to 192.168.165.230192.168.165.2316
62192.168.165.232/29192.168.165.233 to 192.168.165.238192.168.165.2396
63192.168.165.240/29192.168.165.241 to 192.168.165.246192.168.165.2476
64192.168.165.248/29192.168.165.249 to 192.168.165.254192.168.165.2556
65192.168.166.0/29192.168.166.1 to 192.168.166.6192.168.166.76
66192.168.166.8/29192.168.166.9 to 192.168.166.14192.168.166.156
67192.168.166.16/29192.168.166.17 to 192.168.166.22192.168.166.236
68192.168.166.24/29192.168.166.25 to 192.168.166.30192.168.166.316
69192.168.166.32/29192.168.166.33 to 192.168.166.38192.168.166.396
70192.168.166.40/29192.168.166.41 to 192.168.166.46192.168.166.476
71192.168.166.48/29192.168.166.49 to 192.168.166.54192.168.166.556
72192.168.166.56/29192.168.166.57 to 192.168.166.62192.168.166.636
73192.168.166.64/29192.168.166.65 to 192.168.166.70192.168.166.716
74192.168.166.72/29192.168.166.73 to 192.168.166.78192.168.166.796
75192.168.166.80/29192.168.166.81 to 192.168.166.86192.168.166.876
76192.168.166.88/29192.168.166.89 to 192.168.166.94192.168.166.956
77192.168.166.96/29192.168.166.97 to 192.168.166.102192.168.166.1036
78192.168.166.104/29192.168.166.105 to 192.168.166.110192.168.166.1116
79192.168.166.112/29192.168.166.113 to 192.168.166.118192.168.166.1196
80192.168.166.120/29192.168.166.121 to 192.168.166.126192.168.166.1276
81192.168.166.128/29192.168.166.129 to 192.168.166.134192.168.166.1356
82192.168.166.136/29192.168.166.137 to 192.168.166.142192.168.166.1436
83192.168.166.144/29192.168.166.145 to 192.168.166.150192.168.166.1516
84192.168.166.152/29192.168.166.153 to 192.168.166.158192.168.166.1596
85192.168.166.160/29192.168.166.161 to 192.168.166.166192.168.166.1676
86192.168.166.168/29192.168.166.169 to 192.168.166.174192.168.166.1756
87192.168.166.176/29192.168.166.177 to 192.168.166.182192.168.166.1836
88192.168.166.184/29192.168.166.185 to 192.168.166.190192.168.166.1916
89192.168.166.192/29192.168.166.193 to 192.168.166.198192.168.166.1996
90192.168.166.200/29192.168.166.201 to 192.168.166.206192.168.166.2076
91192.168.166.208/29192.168.166.209 to 192.168.166.214192.168.166.2156
92192.168.166.216/29192.168.166.217 to 192.168.166.222192.168.166.2236
93192.168.166.224/29192.168.166.225 to 192.168.166.230192.168.166.2316
94192.168.166.232/29192.168.166.233 to 192.168.166.238192.168.166.2396
95192.168.166.240/29192.168.166.241 to 192.168.166.246192.168.166.2476
96192.168.166.248/29192.168.166.249 to 192.168.166.254192.168.166.2556
97192.168.167.0/29192.168.167.1 to 192.168.167.6192.168.167.76
98192.168.167.8/29192.168.167.9 to 192.168.167.14192.168.167.156
99192.168.167.16/29192.168.167.17 to 192.168.167.22192.168.167.236
100192.168.167.24/29192.168.167.25 to 192.168.167.30192.168.167.316
101192.168.167.32/29192.168.167.33 to 192.168.167.38192.168.167.396
102192.168.167.40/29192.168.167.41 to 192.168.167.46192.168.167.476
103192.168.167.48/29192.168.167.49 to 192.168.167.54192.168.167.556
104192.168.167.56/29192.168.167.57 to 192.168.167.62192.168.167.636
105192.168.167.64/29192.168.167.65 to 192.168.167.70192.168.167.716
106192.168.167.72/29192.168.167.73 to 192.168.167.78192.168.167.796
107192.168.167.80/29192.168.167.81 to 192.168.167.86192.168.167.876
108192.168.167.88/29192.168.167.89 to 192.168.167.94192.168.167.956
109192.168.167.96/29192.168.167.97 to 192.168.167.102192.168.167.1036
110192.168.167.104/29192.168.167.105 to 192.168.167.110192.168.167.1116
111192.168.167.112/29192.168.167.113 to 192.168.167.118192.168.167.1196
112192.168.167.120/29192.168.167.121 to 192.168.167.126192.168.167.1276
113192.168.167.128/29192.168.167.129 to 192.168.167.134192.168.167.1356
114192.168.167.136/29192.168.167.137 to 192.168.167.142192.168.167.1436
115192.168.167.144/29192.168.167.145 to 192.168.167.150192.168.167.1516
116192.168.167.152/29192.168.167.153 to 192.168.167.158192.168.167.1596
117192.168.167.160/29192.168.167.161 to 192.168.167.166192.168.167.1676
118192.168.167.168/29192.168.167.169 to 192.168.167.174192.168.167.1756
119192.168.167.176/29192.168.167.177 to 192.168.167.182192.168.167.1836
120192.168.167.184/29192.168.167.185 to 192.168.167.190192.168.167.1916
121192.168.167.192/29192.168.167.193 to 192.168.167.198192.168.167.1996
122192.168.167.200/29192.168.167.201 to 192.168.167.206192.168.167.2076
123192.168.167.208/29192.168.167.209 to 192.168.167.214192.168.167.2156
124192.168.167.216/29192.168.167.217 to 192.168.167.222192.168.167.2236
125192.168.167.224/29192.168.167.225 to 192.168.167.230192.168.167.2316
126192.168.167.232/29192.168.167.233 to 192.168.167.238192.168.167.2396
127192.168.167.240/29192.168.167.241 to 192.168.167.246192.168.167.2476
128192.168.167.248/29192.168.167.249 to 192.168.167.254192.168.167.2556

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.