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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.

Network152.0.0.0/8
Usable hosts16,777,214
Subnet mask255.0.0.0
Addresses16,777,216
Network address
152.0.0.0
Broadcast address
152.255.255.255
First usable
152.0.0.1
Last usable
152.255.255.254
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
B (default /16)
As numbers
Hex 98000000 · Integer 2550136832 to 2566914047
Reverse DNS zone
152.in-addr.arpa
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address10011000..00000000.00000000.00000000152.0.0.0
Subnet mask11111111..00000000.00000000.00000000255.0.0.0
Network10011000..00000000.00000000.00000000152.0.0.0
Broadcast10011000..11111111.11111111.11111111152.255.255.255
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)

152.0.0.0/8 makes 128 subnets of /15.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1152.0.0.0/15152.0.0.1 to 152.1.255.254152.1.255.255131,070
2152.2.0.0/15152.2.0.1 to 152.3.255.254152.3.255.255131,070
3152.4.0.0/15152.4.0.1 to 152.5.255.254152.5.255.255131,070
4152.6.0.0/15152.6.0.1 to 152.7.255.254152.7.255.255131,070
5152.8.0.0/15152.8.0.1 to 152.9.255.254152.9.255.255131,070
6152.10.0.0/15152.10.0.1 to 152.11.255.254152.11.255.255131,070
7152.12.0.0/15152.12.0.1 to 152.13.255.254152.13.255.255131,070
8152.14.0.0/15152.14.0.1 to 152.15.255.254152.15.255.255131,070
9152.16.0.0/15152.16.0.1 to 152.17.255.254152.17.255.255131,070
10152.18.0.0/15152.18.0.1 to 152.19.255.254152.19.255.255131,070
11152.20.0.0/15152.20.0.1 to 152.21.255.254152.21.255.255131,070
12152.22.0.0/15152.22.0.1 to 152.23.255.254152.23.255.255131,070
13152.24.0.0/15152.24.0.1 to 152.25.255.254152.25.255.255131,070
14152.26.0.0/15152.26.0.1 to 152.27.255.254152.27.255.255131,070
15152.28.0.0/15152.28.0.1 to 152.29.255.254152.29.255.255131,070
16152.30.0.0/15152.30.0.1 to 152.31.255.254152.31.255.255131,070
17152.32.0.0/15152.32.0.1 to 152.33.255.254152.33.255.255131,070
18152.34.0.0/15152.34.0.1 to 152.35.255.254152.35.255.255131,070
19152.36.0.0/15152.36.0.1 to 152.37.255.254152.37.255.255131,070
20152.38.0.0/15152.38.0.1 to 152.39.255.254152.39.255.255131,070
21152.40.0.0/15152.40.0.1 to 152.41.255.254152.41.255.255131,070
22152.42.0.0/15152.42.0.1 to 152.43.255.254152.43.255.255131,070
23152.44.0.0/15152.44.0.1 to 152.45.255.254152.45.255.255131,070
24152.46.0.0/15152.46.0.1 to 152.47.255.254152.47.255.255131,070
25152.48.0.0/15152.48.0.1 to 152.49.255.254152.49.255.255131,070
26152.50.0.0/15152.50.0.1 to 152.51.255.254152.51.255.255131,070
27152.52.0.0/15152.52.0.1 to 152.53.255.254152.53.255.255131,070
28152.54.0.0/15152.54.0.1 to 152.55.255.254152.55.255.255131,070
29152.56.0.0/15152.56.0.1 to 152.57.255.254152.57.255.255131,070
30152.58.0.0/15152.58.0.1 to 152.59.255.254152.59.255.255131,070
31152.60.0.0/15152.60.0.1 to 152.61.255.254152.61.255.255131,070
32152.62.0.0/15152.62.0.1 to 152.63.255.254152.63.255.255131,070
33152.64.0.0/15152.64.0.1 to 152.65.255.254152.65.255.255131,070
34152.66.0.0/15152.66.0.1 to 152.67.255.254152.67.255.255131,070
35152.68.0.0/15152.68.0.1 to 152.69.255.254152.69.255.255131,070
36152.70.0.0/15152.70.0.1 to 152.71.255.254152.71.255.255131,070
37152.72.0.0/15152.72.0.1 to 152.73.255.254152.73.255.255131,070
38152.74.0.0/15152.74.0.1 to 152.75.255.254152.75.255.255131,070
39152.76.0.0/15152.76.0.1 to 152.77.255.254152.77.255.255131,070
40152.78.0.0/15152.78.0.1 to 152.79.255.254152.79.255.255131,070
41152.80.0.0/15152.80.0.1 to 152.81.255.254152.81.255.255131,070
42152.82.0.0/15152.82.0.1 to 152.83.255.254152.83.255.255131,070
43152.84.0.0/15152.84.0.1 to 152.85.255.254152.85.255.255131,070
44152.86.0.0/15152.86.0.1 to 152.87.255.254152.87.255.255131,070
45152.88.0.0/15152.88.0.1 to 152.89.255.254152.89.255.255131,070
46152.90.0.0/15152.90.0.1 to 152.91.255.254152.91.255.255131,070
47152.92.0.0/15152.92.0.1 to 152.93.255.254152.93.255.255131,070
48152.94.0.0/15152.94.0.1 to 152.95.255.254152.95.255.255131,070
49152.96.0.0/15152.96.0.1 to 152.97.255.254152.97.255.255131,070
50152.98.0.0/15152.98.0.1 to 152.99.255.254152.99.255.255131,070
51152.100.0.0/15152.100.0.1 to 152.101.255.254152.101.255.255131,070
52152.102.0.0/15152.102.0.1 to 152.103.255.254152.103.255.255131,070
53152.104.0.0/15152.104.0.1 to 152.105.255.254152.105.255.255131,070
54152.106.0.0/15152.106.0.1 to 152.107.255.254152.107.255.255131,070
55152.108.0.0/15152.108.0.1 to 152.109.255.254152.109.255.255131,070
56152.110.0.0/15152.110.0.1 to 152.111.255.254152.111.255.255131,070
57152.112.0.0/15152.112.0.1 to 152.113.255.254152.113.255.255131,070
58152.114.0.0/15152.114.0.1 to 152.115.255.254152.115.255.255131,070
59152.116.0.0/15152.116.0.1 to 152.117.255.254152.117.255.255131,070
60152.118.0.0/15152.118.0.1 to 152.119.255.254152.119.255.255131,070
61152.120.0.0/15152.120.0.1 to 152.121.255.254152.121.255.255131,070
62152.122.0.0/15152.122.0.1 to 152.123.255.254152.123.255.255131,070
63152.124.0.0/15152.124.0.1 to 152.125.255.254152.125.255.255131,070
64152.126.0.0/15152.126.0.1 to 152.127.255.254152.127.255.255131,070
65152.128.0.0/15152.128.0.1 to 152.129.255.254152.129.255.255131,070
66152.130.0.0/15152.130.0.1 to 152.131.255.254152.131.255.255131,070
67152.132.0.0/15152.132.0.1 to 152.133.255.254152.133.255.255131,070
68152.134.0.0/15152.134.0.1 to 152.135.255.254152.135.255.255131,070
69152.136.0.0/15152.136.0.1 to 152.137.255.254152.137.255.255131,070
70152.138.0.0/15152.138.0.1 to 152.139.255.254152.139.255.255131,070
71152.140.0.0/15152.140.0.1 to 152.141.255.254152.141.255.255131,070
72152.142.0.0/15152.142.0.1 to 152.143.255.254152.143.255.255131,070
73152.144.0.0/15152.144.0.1 to 152.145.255.254152.145.255.255131,070
74152.146.0.0/15152.146.0.1 to 152.147.255.254152.147.255.255131,070
75152.148.0.0/15152.148.0.1 to 152.149.255.254152.149.255.255131,070
76152.150.0.0/15152.150.0.1 to 152.151.255.254152.151.255.255131,070
77152.152.0.0/15152.152.0.1 to 152.153.255.254152.153.255.255131,070
78152.154.0.0/15152.154.0.1 to 152.155.255.254152.155.255.255131,070
79152.156.0.0/15152.156.0.1 to 152.157.255.254152.157.255.255131,070
80152.158.0.0/15152.158.0.1 to 152.159.255.254152.159.255.255131,070
81152.160.0.0/15152.160.0.1 to 152.161.255.254152.161.255.255131,070
82152.162.0.0/15152.162.0.1 to 152.163.255.254152.163.255.255131,070
83152.164.0.0/15152.164.0.1 to 152.165.255.254152.165.255.255131,070
84152.166.0.0/15152.166.0.1 to 152.167.255.254152.167.255.255131,070
85152.168.0.0/15152.168.0.1 to 152.169.255.254152.169.255.255131,070
86152.170.0.0/15152.170.0.1 to 152.171.255.254152.171.255.255131,070
87152.172.0.0/15152.172.0.1 to 152.173.255.254152.173.255.255131,070
88152.174.0.0/15152.174.0.1 to 152.175.255.254152.175.255.255131,070
89152.176.0.0/15152.176.0.1 to 152.177.255.254152.177.255.255131,070
90152.178.0.0/15152.178.0.1 to 152.179.255.254152.179.255.255131,070
91152.180.0.0/15152.180.0.1 to 152.181.255.254152.181.255.255131,070
92152.182.0.0/15152.182.0.1 to 152.183.255.254152.183.255.255131,070
93152.184.0.0/15152.184.0.1 to 152.185.255.254152.185.255.255131,070
94152.186.0.0/15152.186.0.1 to 152.187.255.254152.187.255.255131,070
95152.188.0.0/15152.188.0.1 to 152.189.255.254152.189.255.255131,070
96152.190.0.0/15152.190.0.1 to 152.191.255.254152.191.255.255131,070
97152.192.0.0/15152.192.0.1 to 152.193.255.254152.193.255.255131,070
98152.194.0.0/15152.194.0.1 to 152.195.255.254152.195.255.255131,070
99152.196.0.0/15152.196.0.1 to 152.197.255.254152.197.255.255131,070
100152.198.0.0/15152.198.0.1 to 152.199.255.254152.199.255.255131,070
101152.200.0.0/15152.200.0.1 to 152.201.255.254152.201.255.255131,070
102152.202.0.0/15152.202.0.1 to 152.203.255.254152.203.255.255131,070
103152.204.0.0/15152.204.0.1 to 152.205.255.254152.205.255.255131,070
104152.206.0.0/15152.206.0.1 to 152.207.255.254152.207.255.255131,070
105152.208.0.0/15152.208.0.1 to 152.209.255.254152.209.255.255131,070
106152.210.0.0/15152.210.0.1 to 152.211.255.254152.211.255.255131,070
107152.212.0.0/15152.212.0.1 to 152.213.255.254152.213.255.255131,070
108152.214.0.0/15152.214.0.1 to 152.215.255.254152.215.255.255131,070
109152.216.0.0/15152.216.0.1 to 152.217.255.254152.217.255.255131,070
110152.218.0.0/15152.218.0.1 to 152.219.255.254152.219.255.255131,070
111152.220.0.0/15152.220.0.1 to 152.221.255.254152.221.255.255131,070
112152.222.0.0/15152.222.0.1 to 152.223.255.254152.223.255.255131,070
113152.224.0.0/15152.224.0.1 to 152.225.255.254152.225.255.255131,070
114152.226.0.0/15152.226.0.1 to 152.227.255.254152.227.255.255131,070
115152.228.0.0/15152.228.0.1 to 152.229.255.254152.229.255.255131,070
116152.230.0.0/15152.230.0.1 to 152.231.255.254152.231.255.255131,070
117152.232.0.0/15152.232.0.1 to 152.233.255.254152.233.255.255131,070
118152.234.0.0/15152.234.0.1 to 152.235.255.254152.235.255.255131,070
119152.236.0.0/15152.236.0.1 to 152.237.255.254152.237.255.255131,070
120152.238.0.0/15152.238.0.1 to 152.239.255.254152.239.255.255131,070
121152.240.0.0/15152.240.0.1 to 152.241.255.254152.241.255.255131,070
122152.242.0.0/15152.242.0.1 to 152.243.255.254152.243.255.255131,070
123152.244.0.0/15152.244.0.1 to 152.245.255.254152.245.255.255131,070
124152.246.0.0/15152.246.0.1 to 152.247.255.254152.247.255.255131,070
125152.248.0.0/15152.248.0.1 to 152.249.255.254152.249.255.255131,070
126152.250.0.0/15152.250.0.1 to 152.251.255.254152.251.255.255131,070
127152.252.0.0/15152.252.0.1 to 152.253.255.254152.253.255.255131,070
128152.254.0.0/15152.254.0.1 to 152.255.255.254152.255.255.255131,070

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.