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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.

Network167.32.0.0/11
Usable hosts2,097,150
Subnet mask255.224.0.0
Addresses2,097,152
Network address
167.32.0.0
Broadcast address
167.63.255.255
First usable
167.32.0.1
Last usable
167.63.255.254
Usable hosts
2,097,150 (2,097,152 less the network and broadcast addresses)
Subnet mask
255.224.0.0
Wildcard mask
0.31.255.255 (Cisco ACLs, OSPF)
Prefix length
/11
Type
Public public
Old class
B (default /16)
As numbers
Hex A7200000 · Integer 2803892224 to 2805989375
Reverse DNS zones
32.167.in-addr.arpa
33.167.in-addr.arpa
34.167.in-addr.arpa
35.167.in-addr.arpa
36.167.in-addr.arpa
37.167.in-addr.arpa
38.167.in-addr.arpa
39.167.in-addr.arpa
40.167.in-addr.arpa
41.167.in-addr.arpa
42.167.in-addr.arpa
43.167.in-addr.arpa
44.167.in-addr.arpa
45.167.in-addr.arpa
46.167.in-addr.arpa
47.167.in-addr.arpa
and 16 more
/11 is not on a 8-bit boundary, so it takes 32 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address10100111.00100000.00000000.00000000167.32.0.0
Subnet mask11111111.11100000.00000000.00000000255.224.0.0
Network10100111.00100000.00000000.00000000167.32.0.0
Broadcast10100111.00111111.11111111.11111111167.63.255.255
Split into smaller subnets/18
/12 (2)/13 (4)/14 (8)/15 (16)/16 (32)/17 (64)/18 (128)/19 (256)/20 (512)/21 (1,024)/22 (2,048)/23 (4,096)

167.32.0.0/11 makes 128 subnets of /18.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1167.32.0.0/18167.32.0.1 to 167.32.63.254167.32.63.25516,382
2167.32.64.0/18167.32.64.1 to 167.32.127.254167.32.127.25516,382
3167.32.128.0/18167.32.128.1 to 167.32.191.254167.32.191.25516,382
4167.32.192.0/18167.32.192.1 to 167.32.255.254167.32.255.25516,382
5167.33.0.0/18167.33.0.1 to 167.33.63.254167.33.63.25516,382
6167.33.64.0/18167.33.64.1 to 167.33.127.254167.33.127.25516,382
7167.33.128.0/18167.33.128.1 to 167.33.191.254167.33.191.25516,382
8167.33.192.0/18167.33.192.1 to 167.33.255.254167.33.255.25516,382
9167.34.0.0/18167.34.0.1 to 167.34.63.254167.34.63.25516,382
10167.34.64.0/18167.34.64.1 to 167.34.127.254167.34.127.25516,382
11167.34.128.0/18167.34.128.1 to 167.34.191.254167.34.191.25516,382
12167.34.192.0/18167.34.192.1 to 167.34.255.254167.34.255.25516,382
13167.35.0.0/18167.35.0.1 to 167.35.63.254167.35.63.25516,382
14167.35.64.0/18167.35.64.1 to 167.35.127.254167.35.127.25516,382
15167.35.128.0/18167.35.128.1 to 167.35.191.254167.35.191.25516,382
16167.35.192.0/18167.35.192.1 to 167.35.255.254167.35.255.25516,382
17167.36.0.0/18167.36.0.1 to 167.36.63.254167.36.63.25516,382
18167.36.64.0/18167.36.64.1 to 167.36.127.254167.36.127.25516,382
19167.36.128.0/18167.36.128.1 to 167.36.191.254167.36.191.25516,382
20167.36.192.0/18167.36.192.1 to 167.36.255.254167.36.255.25516,382
21167.37.0.0/18167.37.0.1 to 167.37.63.254167.37.63.25516,382
22167.37.64.0/18167.37.64.1 to 167.37.127.254167.37.127.25516,382
23167.37.128.0/18167.37.128.1 to 167.37.191.254167.37.191.25516,382
24167.37.192.0/18167.37.192.1 to 167.37.255.254167.37.255.25516,382
25167.38.0.0/18167.38.0.1 to 167.38.63.254167.38.63.25516,382
26167.38.64.0/18167.38.64.1 to 167.38.127.254167.38.127.25516,382
27167.38.128.0/18167.38.128.1 to 167.38.191.254167.38.191.25516,382
28167.38.192.0/18167.38.192.1 to 167.38.255.254167.38.255.25516,382
29167.39.0.0/18167.39.0.1 to 167.39.63.254167.39.63.25516,382
30167.39.64.0/18167.39.64.1 to 167.39.127.254167.39.127.25516,382
31167.39.128.0/18167.39.128.1 to 167.39.191.254167.39.191.25516,382
32167.39.192.0/18167.39.192.1 to 167.39.255.254167.39.255.25516,382
33167.40.0.0/18167.40.0.1 to 167.40.63.254167.40.63.25516,382
34167.40.64.0/18167.40.64.1 to 167.40.127.254167.40.127.25516,382
35167.40.128.0/18167.40.128.1 to 167.40.191.254167.40.191.25516,382
36167.40.192.0/18167.40.192.1 to 167.40.255.254167.40.255.25516,382
37167.41.0.0/18167.41.0.1 to 167.41.63.254167.41.63.25516,382
38167.41.64.0/18167.41.64.1 to 167.41.127.254167.41.127.25516,382
39167.41.128.0/18167.41.128.1 to 167.41.191.254167.41.191.25516,382
40167.41.192.0/18167.41.192.1 to 167.41.255.254167.41.255.25516,382
41167.42.0.0/18167.42.0.1 to 167.42.63.254167.42.63.25516,382
42167.42.64.0/18167.42.64.1 to 167.42.127.254167.42.127.25516,382
43167.42.128.0/18167.42.128.1 to 167.42.191.254167.42.191.25516,382
44167.42.192.0/18167.42.192.1 to 167.42.255.254167.42.255.25516,382
45167.43.0.0/18167.43.0.1 to 167.43.63.254167.43.63.25516,382
46167.43.64.0/18167.43.64.1 to 167.43.127.254167.43.127.25516,382
47167.43.128.0/18167.43.128.1 to 167.43.191.254167.43.191.25516,382
48167.43.192.0/18167.43.192.1 to 167.43.255.254167.43.255.25516,382
49167.44.0.0/18167.44.0.1 to 167.44.63.254167.44.63.25516,382
50167.44.64.0/18167.44.64.1 to 167.44.127.254167.44.127.25516,382
51167.44.128.0/18167.44.128.1 to 167.44.191.254167.44.191.25516,382
52167.44.192.0/18167.44.192.1 to 167.44.255.254167.44.255.25516,382
53167.45.0.0/18167.45.0.1 to 167.45.63.254167.45.63.25516,382
54167.45.64.0/18167.45.64.1 to 167.45.127.254167.45.127.25516,382
55167.45.128.0/18167.45.128.1 to 167.45.191.254167.45.191.25516,382
56167.45.192.0/18167.45.192.1 to 167.45.255.254167.45.255.25516,382
57167.46.0.0/18167.46.0.1 to 167.46.63.254167.46.63.25516,382
58167.46.64.0/18167.46.64.1 to 167.46.127.254167.46.127.25516,382
59167.46.128.0/18167.46.128.1 to 167.46.191.254167.46.191.25516,382
60167.46.192.0/18167.46.192.1 to 167.46.255.254167.46.255.25516,382
61167.47.0.0/18167.47.0.1 to 167.47.63.254167.47.63.25516,382
62167.47.64.0/18167.47.64.1 to 167.47.127.254167.47.127.25516,382
63167.47.128.0/18167.47.128.1 to 167.47.191.254167.47.191.25516,382
64167.47.192.0/18167.47.192.1 to 167.47.255.254167.47.255.25516,382
65167.48.0.0/18167.48.0.1 to 167.48.63.254167.48.63.25516,382
66167.48.64.0/18167.48.64.1 to 167.48.127.254167.48.127.25516,382
67167.48.128.0/18167.48.128.1 to 167.48.191.254167.48.191.25516,382
68167.48.192.0/18167.48.192.1 to 167.48.255.254167.48.255.25516,382
69167.49.0.0/18167.49.0.1 to 167.49.63.254167.49.63.25516,382
70167.49.64.0/18167.49.64.1 to 167.49.127.254167.49.127.25516,382
71167.49.128.0/18167.49.128.1 to 167.49.191.254167.49.191.25516,382
72167.49.192.0/18167.49.192.1 to 167.49.255.254167.49.255.25516,382
73167.50.0.0/18167.50.0.1 to 167.50.63.254167.50.63.25516,382
74167.50.64.0/18167.50.64.1 to 167.50.127.254167.50.127.25516,382
75167.50.128.0/18167.50.128.1 to 167.50.191.254167.50.191.25516,382
76167.50.192.0/18167.50.192.1 to 167.50.255.254167.50.255.25516,382
77167.51.0.0/18167.51.0.1 to 167.51.63.254167.51.63.25516,382
78167.51.64.0/18167.51.64.1 to 167.51.127.254167.51.127.25516,382
79167.51.128.0/18167.51.128.1 to 167.51.191.254167.51.191.25516,382
80167.51.192.0/18167.51.192.1 to 167.51.255.254167.51.255.25516,382
81167.52.0.0/18167.52.0.1 to 167.52.63.254167.52.63.25516,382
82167.52.64.0/18167.52.64.1 to 167.52.127.254167.52.127.25516,382
83167.52.128.0/18167.52.128.1 to 167.52.191.254167.52.191.25516,382
84167.52.192.0/18167.52.192.1 to 167.52.255.254167.52.255.25516,382
85167.53.0.0/18167.53.0.1 to 167.53.63.254167.53.63.25516,382
86167.53.64.0/18167.53.64.1 to 167.53.127.254167.53.127.25516,382
87167.53.128.0/18167.53.128.1 to 167.53.191.254167.53.191.25516,382
88167.53.192.0/18167.53.192.1 to 167.53.255.254167.53.255.25516,382
89167.54.0.0/18167.54.0.1 to 167.54.63.254167.54.63.25516,382
90167.54.64.0/18167.54.64.1 to 167.54.127.254167.54.127.25516,382
91167.54.128.0/18167.54.128.1 to 167.54.191.254167.54.191.25516,382
92167.54.192.0/18167.54.192.1 to 167.54.255.254167.54.255.25516,382
93167.55.0.0/18167.55.0.1 to 167.55.63.254167.55.63.25516,382
94167.55.64.0/18167.55.64.1 to 167.55.127.254167.55.127.25516,382
95167.55.128.0/18167.55.128.1 to 167.55.191.254167.55.191.25516,382
96167.55.192.0/18167.55.192.1 to 167.55.255.254167.55.255.25516,382
97167.56.0.0/18167.56.0.1 to 167.56.63.254167.56.63.25516,382
98167.56.64.0/18167.56.64.1 to 167.56.127.254167.56.127.25516,382
99167.56.128.0/18167.56.128.1 to 167.56.191.254167.56.191.25516,382
100167.56.192.0/18167.56.192.1 to 167.56.255.254167.56.255.25516,382
101167.57.0.0/18167.57.0.1 to 167.57.63.254167.57.63.25516,382
102167.57.64.0/18167.57.64.1 to 167.57.127.254167.57.127.25516,382
103167.57.128.0/18167.57.128.1 to 167.57.191.254167.57.191.25516,382
104167.57.192.0/18167.57.192.1 to 167.57.255.254167.57.255.25516,382
105167.58.0.0/18167.58.0.1 to 167.58.63.254167.58.63.25516,382
106167.58.64.0/18167.58.64.1 to 167.58.127.254167.58.127.25516,382
107167.58.128.0/18167.58.128.1 to 167.58.191.254167.58.191.25516,382
108167.58.192.0/18167.58.192.1 to 167.58.255.254167.58.255.25516,382
109167.59.0.0/18167.59.0.1 to 167.59.63.254167.59.63.25516,382
110167.59.64.0/18167.59.64.1 to 167.59.127.254167.59.127.25516,382
111167.59.128.0/18167.59.128.1 to 167.59.191.254167.59.191.25516,382
112167.59.192.0/18167.59.192.1 to 167.59.255.254167.59.255.25516,382
113167.60.0.0/18167.60.0.1 to 167.60.63.254167.60.63.25516,382
114167.60.64.0/18167.60.64.1 to 167.60.127.254167.60.127.25516,382
115167.60.128.0/18167.60.128.1 to 167.60.191.254167.60.191.25516,382
116167.60.192.0/18167.60.192.1 to 167.60.255.254167.60.255.25516,382
117167.61.0.0/18167.61.0.1 to 167.61.63.254167.61.63.25516,382
118167.61.64.0/18167.61.64.1 to 167.61.127.254167.61.127.25516,382
119167.61.128.0/18167.61.128.1 to 167.61.191.254167.61.191.25516,382
120167.61.192.0/18167.61.192.1 to 167.61.255.254167.61.255.25516,382
121167.62.0.0/18167.62.0.1 to 167.62.63.254167.62.63.25516,382
122167.62.64.0/18167.62.64.1 to 167.62.127.254167.62.127.25516,382
123167.62.128.0/18167.62.128.1 to 167.62.191.254167.62.191.25516,382
124167.62.192.0/18167.62.192.1 to 167.62.255.254167.62.255.25516,382
125167.63.0.0/18167.63.0.1 to 167.63.63.254167.63.63.25516,382
126167.63.64.0/18167.63.64.1 to 167.63.127.254167.63.127.25516,382
127167.63.128.0/18167.63.128.1 to 167.63.191.254167.63.191.25516,382
128167.63.192.0/18167.63.192.1 to 167.63.255.254167.63.255.25516,382

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.