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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.

Network119.0.0.0/8
Usable hosts16,777,214
Subnet mask255.0.0.0
Addresses16,777,216
Network address
119.0.0.0
Broadcast address
119.255.255.255
First usable
119.0.0.1
Last usable
119.255.255.254
Usable hosts
16,777,214 (16,777,216 less the network and broadcast addresses)
Subnet mask
255.0.0.0
Wildcard mask
0.255.255.255 (Cisco ACLs, OSPF)
Prefix length
/8
Type
Public public
Old class
A (default /8)
As numbers
Hex 77000000 · Integer 1996488704 to 2013265919
Reverse DNS zone
119.in-addr.arpa
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address01110111..00000000.00000000.00000000119.0.0.0
Subnet mask11111111..00000000.00000000.00000000255.0.0.0
Network01110111..00000000.00000000.00000000119.0.0.0
Broadcast01110111..11111111.11111111.11111111119.255.255.255
Split into smaller subnets/15
/9 (2)/10 (4)/11 (8)/12 (16)/13 (32)/14 (64)/15 (128)/16 (256)/17 (512)/18 (1,024)/19 (2,048)/20 (4,096)

119.0.0.0/8 makes 128 subnets of /15.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1119.0.0.0/15119.0.0.1 to 119.1.255.254119.1.255.255131,070
2119.2.0.0/15119.2.0.1 to 119.3.255.254119.3.255.255131,070
3119.4.0.0/15119.4.0.1 to 119.5.255.254119.5.255.255131,070
4119.6.0.0/15119.6.0.1 to 119.7.255.254119.7.255.255131,070
5119.8.0.0/15119.8.0.1 to 119.9.255.254119.9.255.255131,070
6119.10.0.0/15119.10.0.1 to 119.11.255.254119.11.255.255131,070
7119.12.0.0/15119.12.0.1 to 119.13.255.254119.13.255.255131,070
8119.14.0.0/15119.14.0.1 to 119.15.255.254119.15.255.255131,070
9119.16.0.0/15119.16.0.1 to 119.17.255.254119.17.255.255131,070
10119.18.0.0/15119.18.0.1 to 119.19.255.254119.19.255.255131,070
11119.20.0.0/15119.20.0.1 to 119.21.255.254119.21.255.255131,070
12119.22.0.0/15119.22.0.1 to 119.23.255.254119.23.255.255131,070
13119.24.0.0/15119.24.0.1 to 119.25.255.254119.25.255.255131,070
14119.26.0.0/15119.26.0.1 to 119.27.255.254119.27.255.255131,070
15119.28.0.0/15119.28.0.1 to 119.29.255.254119.29.255.255131,070
16119.30.0.0/15119.30.0.1 to 119.31.255.254119.31.255.255131,070
17119.32.0.0/15119.32.0.1 to 119.33.255.254119.33.255.255131,070
18119.34.0.0/15119.34.0.1 to 119.35.255.254119.35.255.255131,070
19119.36.0.0/15119.36.0.1 to 119.37.255.254119.37.255.255131,070
20119.38.0.0/15119.38.0.1 to 119.39.255.254119.39.255.255131,070
21119.40.0.0/15119.40.0.1 to 119.41.255.254119.41.255.255131,070
22119.42.0.0/15119.42.0.1 to 119.43.255.254119.43.255.255131,070
23119.44.0.0/15119.44.0.1 to 119.45.255.254119.45.255.255131,070
24119.46.0.0/15119.46.0.1 to 119.47.255.254119.47.255.255131,070
25119.48.0.0/15119.48.0.1 to 119.49.255.254119.49.255.255131,070
26119.50.0.0/15119.50.0.1 to 119.51.255.254119.51.255.255131,070
27119.52.0.0/15119.52.0.1 to 119.53.255.254119.53.255.255131,070
28119.54.0.0/15119.54.0.1 to 119.55.255.254119.55.255.255131,070
29119.56.0.0/15119.56.0.1 to 119.57.255.254119.57.255.255131,070
30119.58.0.0/15119.58.0.1 to 119.59.255.254119.59.255.255131,070
31119.60.0.0/15119.60.0.1 to 119.61.255.254119.61.255.255131,070
32119.62.0.0/15119.62.0.1 to 119.63.255.254119.63.255.255131,070
33119.64.0.0/15119.64.0.1 to 119.65.255.254119.65.255.255131,070
34119.66.0.0/15119.66.0.1 to 119.67.255.254119.67.255.255131,070
35119.68.0.0/15119.68.0.1 to 119.69.255.254119.69.255.255131,070
36119.70.0.0/15119.70.0.1 to 119.71.255.254119.71.255.255131,070
37119.72.0.0/15119.72.0.1 to 119.73.255.254119.73.255.255131,070
38119.74.0.0/15119.74.0.1 to 119.75.255.254119.75.255.255131,070
39119.76.0.0/15119.76.0.1 to 119.77.255.254119.77.255.255131,070
40119.78.0.0/15119.78.0.1 to 119.79.255.254119.79.255.255131,070
41119.80.0.0/15119.80.0.1 to 119.81.255.254119.81.255.255131,070
42119.82.0.0/15119.82.0.1 to 119.83.255.254119.83.255.255131,070
43119.84.0.0/15119.84.0.1 to 119.85.255.254119.85.255.255131,070
44119.86.0.0/15119.86.0.1 to 119.87.255.254119.87.255.255131,070
45119.88.0.0/15119.88.0.1 to 119.89.255.254119.89.255.255131,070
46119.90.0.0/15119.90.0.1 to 119.91.255.254119.91.255.255131,070
47119.92.0.0/15119.92.0.1 to 119.93.255.254119.93.255.255131,070
48119.94.0.0/15119.94.0.1 to 119.95.255.254119.95.255.255131,070
49119.96.0.0/15119.96.0.1 to 119.97.255.254119.97.255.255131,070
50119.98.0.0/15119.98.0.1 to 119.99.255.254119.99.255.255131,070
51119.100.0.0/15119.100.0.1 to 119.101.255.254119.101.255.255131,070
52119.102.0.0/15119.102.0.1 to 119.103.255.254119.103.255.255131,070
53119.104.0.0/15119.104.0.1 to 119.105.255.254119.105.255.255131,070
54119.106.0.0/15119.106.0.1 to 119.107.255.254119.107.255.255131,070
55119.108.0.0/15119.108.0.1 to 119.109.255.254119.109.255.255131,070
56119.110.0.0/15119.110.0.1 to 119.111.255.254119.111.255.255131,070
57119.112.0.0/15119.112.0.1 to 119.113.255.254119.113.255.255131,070
58119.114.0.0/15119.114.0.1 to 119.115.255.254119.115.255.255131,070
59119.116.0.0/15119.116.0.1 to 119.117.255.254119.117.255.255131,070
60119.118.0.0/15119.118.0.1 to 119.119.255.254119.119.255.255131,070
61119.120.0.0/15119.120.0.1 to 119.121.255.254119.121.255.255131,070
62119.122.0.0/15119.122.0.1 to 119.123.255.254119.123.255.255131,070
63119.124.0.0/15119.124.0.1 to 119.125.255.254119.125.255.255131,070
64119.126.0.0/15119.126.0.1 to 119.127.255.254119.127.255.255131,070
65119.128.0.0/15119.128.0.1 to 119.129.255.254119.129.255.255131,070
66119.130.0.0/15119.130.0.1 to 119.131.255.254119.131.255.255131,070
67119.132.0.0/15119.132.0.1 to 119.133.255.254119.133.255.255131,070
68119.134.0.0/15119.134.0.1 to 119.135.255.254119.135.255.255131,070
69119.136.0.0/15119.136.0.1 to 119.137.255.254119.137.255.255131,070
70119.138.0.0/15119.138.0.1 to 119.139.255.254119.139.255.255131,070
71119.140.0.0/15119.140.0.1 to 119.141.255.254119.141.255.255131,070
72119.142.0.0/15119.142.0.1 to 119.143.255.254119.143.255.255131,070
73119.144.0.0/15119.144.0.1 to 119.145.255.254119.145.255.255131,070
74119.146.0.0/15119.146.0.1 to 119.147.255.254119.147.255.255131,070
75119.148.0.0/15119.148.0.1 to 119.149.255.254119.149.255.255131,070
76119.150.0.0/15119.150.0.1 to 119.151.255.254119.151.255.255131,070
77119.152.0.0/15119.152.0.1 to 119.153.255.254119.153.255.255131,070
78119.154.0.0/15119.154.0.1 to 119.155.255.254119.155.255.255131,070
79119.156.0.0/15119.156.0.1 to 119.157.255.254119.157.255.255131,070
80119.158.0.0/15119.158.0.1 to 119.159.255.254119.159.255.255131,070
81119.160.0.0/15119.160.0.1 to 119.161.255.254119.161.255.255131,070
82119.162.0.0/15119.162.0.1 to 119.163.255.254119.163.255.255131,070
83119.164.0.0/15119.164.0.1 to 119.165.255.254119.165.255.255131,070
84119.166.0.0/15119.166.0.1 to 119.167.255.254119.167.255.255131,070
85119.168.0.0/15119.168.0.1 to 119.169.255.254119.169.255.255131,070
86119.170.0.0/15119.170.0.1 to 119.171.255.254119.171.255.255131,070
87119.172.0.0/15119.172.0.1 to 119.173.255.254119.173.255.255131,070
88119.174.0.0/15119.174.0.1 to 119.175.255.254119.175.255.255131,070
89119.176.0.0/15119.176.0.1 to 119.177.255.254119.177.255.255131,070
90119.178.0.0/15119.178.0.1 to 119.179.255.254119.179.255.255131,070
91119.180.0.0/15119.180.0.1 to 119.181.255.254119.181.255.255131,070
92119.182.0.0/15119.182.0.1 to 119.183.255.254119.183.255.255131,070
93119.184.0.0/15119.184.0.1 to 119.185.255.254119.185.255.255131,070
94119.186.0.0/15119.186.0.1 to 119.187.255.254119.187.255.255131,070
95119.188.0.0/15119.188.0.1 to 119.189.255.254119.189.255.255131,070
96119.190.0.0/15119.190.0.1 to 119.191.255.254119.191.255.255131,070
97119.192.0.0/15119.192.0.1 to 119.193.255.254119.193.255.255131,070
98119.194.0.0/15119.194.0.1 to 119.195.255.254119.195.255.255131,070
99119.196.0.0/15119.196.0.1 to 119.197.255.254119.197.255.255131,070
100119.198.0.0/15119.198.0.1 to 119.199.255.254119.199.255.255131,070
101119.200.0.0/15119.200.0.1 to 119.201.255.254119.201.255.255131,070
102119.202.0.0/15119.202.0.1 to 119.203.255.254119.203.255.255131,070
103119.204.0.0/15119.204.0.1 to 119.205.255.254119.205.255.255131,070
104119.206.0.0/15119.206.0.1 to 119.207.255.254119.207.255.255131,070
105119.208.0.0/15119.208.0.1 to 119.209.255.254119.209.255.255131,070
106119.210.0.0/15119.210.0.1 to 119.211.255.254119.211.255.255131,070
107119.212.0.0/15119.212.0.1 to 119.213.255.254119.213.255.255131,070
108119.214.0.0/15119.214.0.1 to 119.215.255.254119.215.255.255131,070
109119.216.0.0/15119.216.0.1 to 119.217.255.254119.217.255.255131,070
110119.218.0.0/15119.218.0.1 to 119.219.255.254119.219.255.255131,070
111119.220.0.0/15119.220.0.1 to 119.221.255.254119.221.255.255131,070
112119.222.0.0/15119.222.0.1 to 119.223.255.254119.223.255.255131,070
113119.224.0.0/15119.224.0.1 to 119.225.255.254119.225.255.255131,070
114119.226.0.0/15119.226.0.1 to 119.227.255.254119.227.255.255131,070
115119.228.0.0/15119.228.0.1 to 119.229.255.254119.229.255.255131,070
116119.230.0.0/15119.230.0.1 to 119.231.255.254119.231.255.255131,070
117119.232.0.0/15119.232.0.1 to 119.233.255.254119.233.255.255131,070
118119.234.0.0/15119.234.0.1 to 119.235.255.254119.235.255.255131,070
119119.236.0.0/15119.236.0.1 to 119.237.255.254119.237.255.255131,070
120119.238.0.0/15119.238.0.1 to 119.239.255.254119.239.255.255131,070
121119.240.0.0/15119.240.0.1 to 119.241.255.254119.241.255.255131,070
122119.242.0.0/15119.242.0.1 to 119.243.255.254119.243.255.255131,070
123119.244.0.0/15119.244.0.1 to 119.245.255.254119.245.255.255131,070
124119.246.0.0/15119.246.0.1 to 119.247.255.254119.247.255.255131,070
125119.248.0.0/15119.248.0.1 to 119.249.255.254119.249.255.255131,070
126119.250.0.0/15119.250.0.1 to 119.251.255.254119.251.255.255131,070
127119.252.0.0/15119.252.0.1 to 119.253.255.254119.253.255.255131,070
128119.254.0.0/15119.254.0.1 to 119.255.255.254119.255.255.255131,070

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.