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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.

Network86.136.0.0/13
Usable hosts524,286
Subnet mask255.248.0.0
Addresses524,288
Network address
86.136.0.0
Broadcast address
86.143.255.255
First usable
86.136.0.1
Last usable
86.143.255.254
Usable hosts
524,286 (524,288 less the network and broadcast addresses)
Subnet mask
255.248.0.0
Wildcard mask
0.7.255.255 (Cisco ACLs, OSPF)
Prefix length
/13
Type
Public public
Old class
A (default /8)
As numbers
Hex 56880000 · Integer 1451753472 to 1452277759
Reverse DNS zones
136.86.in-addr.arpa
137.86.in-addr.arpa
138.86.in-addr.arpa
139.86.in-addr.arpa
140.86.in-addr.arpa
141.86.in-addr.arpa
142.86.in-addr.arpa
143.86.in-addr.arpa
/13 is not on a 8-bit boundary, so it takes 8 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address01010110.10001000.00000000.0000000086.136.0.0
Subnet mask11111111.11111000.00000000.00000000255.248.0.0
Network01010110.10001000.00000000.0000000086.136.0.0
Broadcast01010110.10001111.11111111.1111111186.143.255.255
Split into smaller subnets/20
/14 (2)/15 (4)/16 (8)/17 (16)/18 (32)/19 (64)/20 (128)/21 (256)/22 (512)/23 (1,024)/24 (2,048)/25 (4,096)

86.136.0.0/13 makes 128 subnets of /20.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
186.136.0.0/2086.136.0.1 to 86.136.15.25486.136.15.2554,094
286.136.16.0/2086.136.16.1 to 86.136.31.25486.136.31.2554,094
386.136.32.0/2086.136.32.1 to 86.136.47.25486.136.47.2554,094
486.136.48.0/2086.136.48.1 to 86.136.63.25486.136.63.2554,094
586.136.64.0/2086.136.64.1 to 86.136.79.25486.136.79.2554,094
686.136.80.0/2086.136.80.1 to 86.136.95.25486.136.95.2554,094
786.136.96.0/2086.136.96.1 to 86.136.111.25486.136.111.2554,094
886.136.112.0/2086.136.112.1 to 86.136.127.25486.136.127.2554,094
986.136.128.0/2086.136.128.1 to 86.136.143.25486.136.143.2554,094
1086.136.144.0/2086.136.144.1 to 86.136.159.25486.136.159.2554,094
1186.136.160.0/2086.136.160.1 to 86.136.175.25486.136.175.2554,094
1286.136.176.0/2086.136.176.1 to 86.136.191.25486.136.191.2554,094
1386.136.192.0/2086.136.192.1 to 86.136.207.25486.136.207.2554,094
1486.136.208.0/2086.136.208.1 to 86.136.223.25486.136.223.2554,094
1586.136.224.0/2086.136.224.1 to 86.136.239.25486.136.239.2554,094
1686.136.240.0/2086.136.240.1 to 86.136.255.25486.136.255.2554,094
1786.137.0.0/2086.137.0.1 to 86.137.15.25486.137.15.2554,094
1886.137.16.0/2086.137.16.1 to 86.137.31.25486.137.31.2554,094
1986.137.32.0/2086.137.32.1 to 86.137.47.25486.137.47.2554,094
2086.137.48.0/2086.137.48.1 to 86.137.63.25486.137.63.2554,094
2186.137.64.0/2086.137.64.1 to 86.137.79.25486.137.79.2554,094
2286.137.80.0/2086.137.80.1 to 86.137.95.25486.137.95.2554,094
2386.137.96.0/2086.137.96.1 to 86.137.111.25486.137.111.2554,094
2486.137.112.0/2086.137.112.1 to 86.137.127.25486.137.127.2554,094
2586.137.128.0/2086.137.128.1 to 86.137.143.25486.137.143.2554,094
2686.137.144.0/2086.137.144.1 to 86.137.159.25486.137.159.2554,094
2786.137.160.0/2086.137.160.1 to 86.137.175.25486.137.175.2554,094
2886.137.176.0/2086.137.176.1 to 86.137.191.25486.137.191.2554,094
2986.137.192.0/2086.137.192.1 to 86.137.207.25486.137.207.2554,094
3086.137.208.0/2086.137.208.1 to 86.137.223.25486.137.223.2554,094
3186.137.224.0/2086.137.224.1 to 86.137.239.25486.137.239.2554,094
3286.137.240.0/2086.137.240.1 to 86.137.255.25486.137.255.2554,094
3386.138.0.0/2086.138.0.1 to 86.138.15.25486.138.15.2554,094
3486.138.16.0/2086.138.16.1 to 86.138.31.25486.138.31.2554,094
3586.138.32.0/2086.138.32.1 to 86.138.47.25486.138.47.2554,094
3686.138.48.0/2086.138.48.1 to 86.138.63.25486.138.63.2554,094
3786.138.64.0/2086.138.64.1 to 86.138.79.25486.138.79.2554,094
3886.138.80.0/2086.138.80.1 to 86.138.95.25486.138.95.2554,094
3986.138.96.0/2086.138.96.1 to 86.138.111.25486.138.111.2554,094
4086.138.112.0/2086.138.112.1 to 86.138.127.25486.138.127.2554,094
4186.138.128.0/2086.138.128.1 to 86.138.143.25486.138.143.2554,094
4286.138.144.0/2086.138.144.1 to 86.138.159.25486.138.159.2554,094
4386.138.160.0/2086.138.160.1 to 86.138.175.25486.138.175.2554,094
4486.138.176.0/2086.138.176.1 to 86.138.191.25486.138.191.2554,094
4586.138.192.0/2086.138.192.1 to 86.138.207.25486.138.207.2554,094
4686.138.208.0/2086.138.208.1 to 86.138.223.25486.138.223.2554,094
4786.138.224.0/2086.138.224.1 to 86.138.239.25486.138.239.2554,094
4886.138.240.0/2086.138.240.1 to 86.138.255.25486.138.255.2554,094
4986.139.0.0/2086.139.0.1 to 86.139.15.25486.139.15.2554,094
5086.139.16.0/2086.139.16.1 to 86.139.31.25486.139.31.2554,094
5186.139.32.0/2086.139.32.1 to 86.139.47.25486.139.47.2554,094
5286.139.48.0/2086.139.48.1 to 86.139.63.25486.139.63.2554,094
5386.139.64.0/2086.139.64.1 to 86.139.79.25486.139.79.2554,094
5486.139.80.0/2086.139.80.1 to 86.139.95.25486.139.95.2554,094
5586.139.96.0/2086.139.96.1 to 86.139.111.25486.139.111.2554,094
5686.139.112.0/2086.139.112.1 to 86.139.127.25486.139.127.2554,094
5786.139.128.0/2086.139.128.1 to 86.139.143.25486.139.143.2554,094
5886.139.144.0/2086.139.144.1 to 86.139.159.25486.139.159.2554,094
5986.139.160.0/2086.139.160.1 to 86.139.175.25486.139.175.2554,094
6086.139.176.0/2086.139.176.1 to 86.139.191.25486.139.191.2554,094
6186.139.192.0/2086.139.192.1 to 86.139.207.25486.139.207.2554,094
6286.139.208.0/2086.139.208.1 to 86.139.223.25486.139.223.2554,094
6386.139.224.0/2086.139.224.1 to 86.139.239.25486.139.239.2554,094
6486.139.240.0/2086.139.240.1 to 86.139.255.25486.139.255.2554,094
6586.140.0.0/2086.140.0.1 to 86.140.15.25486.140.15.2554,094
6686.140.16.0/2086.140.16.1 to 86.140.31.25486.140.31.2554,094
6786.140.32.0/2086.140.32.1 to 86.140.47.25486.140.47.2554,094
6886.140.48.0/2086.140.48.1 to 86.140.63.25486.140.63.2554,094
6986.140.64.0/2086.140.64.1 to 86.140.79.25486.140.79.2554,094
7086.140.80.0/2086.140.80.1 to 86.140.95.25486.140.95.2554,094
7186.140.96.0/2086.140.96.1 to 86.140.111.25486.140.111.2554,094
7286.140.112.0/2086.140.112.1 to 86.140.127.25486.140.127.2554,094
7386.140.128.0/2086.140.128.1 to 86.140.143.25486.140.143.2554,094
7486.140.144.0/2086.140.144.1 to 86.140.159.25486.140.159.2554,094
7586.140.160.0/2086.140.160.1 to 86.140.175.25486.140.175.2554,094
7686.140.176.0/2086.140.176.1 to 86.140.191.25486.140.191.2554,094
7786.140.192.0/2086.140.192.1 to 86.140.207.25486.140.207.2554,094
7886.140.208.0/2086.140.208.1 to 86.140.223.25486.140.223.2554,094
7986.140.224.0/2086.140.224.1 to 86.140.239.25486.140.239.2554,094
8086.140.240.0/2086.140.240.1 to 86.140.255.25486.140.255.2554,094
8186.141.0.0/2086.141.0.1 to 86.141.15.25486.141.15.2554,094
8286.141.16.0/2086.141.16.1 to 86.141.31.25486.141.31.2554,094
8386.141.32.0/2086.141.32.1 to 86.141.47.25486.141.47.2554,094
8486.141.48.0/2086.141.48.1 to 86.141.63.25486.141.63.2554,094
8586.141.64.0/2086.141.64.1 to 86.141.79.25486.141.79.2554,094
8686.141.80.0/2086.141.80.1 to 86.141.95.25486.141.95.2554,094
8786.141.96.0/2086.141.96.1 to 86.141.111.25486.141.111.2554,094
8886.141.112.0/2086.141.112.1 to 86.141.127.25486.141.127.2554,094
8986.141.128.0/2086.141.128.1 to 86.141.143.25486.141.143.2554,094
9086.141.144.0/2086.141.144.1 to 86.141.159.25486.141.159.2554,094
9186.141.160.0/2086.141.160.1 to 86.141.175.25486.141.175.2554,094
9286.141.176.0/2086.141.176.1 to 86.141.191.25486.141.191.2554,094
9386.141.192.0/2086.141.192.1 to 86.141.207.25486.141.207.2554,094
9486.141.208.0/2086.141.208.1 to 86.141.223.25486.141.223.2554,094
9586.141.224.0/2086.141.224.1 to 86.141.239.25486.141.239.2554,094
9686.141.240.0/2086.141.240.1 to 86.141.255.25486.141.255.2554,094
9786.142.0.0/2086.142.0.1 to 86.142.15.25486.142.15.2554,094
9886.142.16.0/2086.142.16.1 to 86.142.31.25486.142.31.2554,094
9986.142.32.0/2086.142.32.1 to 86.142.47.25486.142.47.2554,094
10086.142.48.0/2086.142.48.1 to 86.142.63.25486.142.63.2554,094
10186.142.64.0/2086.142.64.1 to 86.142.79.25486.142.79.2554,094
10286.142.80.0/2086.142.80.1 to 86.142.95.25486.142.95.2554,094
10386.142.96.0/2086.142.96.1 to 86.142.111.25486.142.111.2554,094
10486.142.112.0/2086.142.112.1 to 86.142.127.25486.142.127.2554,094
10586.142.128.0/2086.142.128.1 to 86.142.143.25486.142.143.2554,094
10686.142.144.0/2086.142.144.1 to 86.142.159.25486.142.159.2554,094
10786.142.160.0/2086.142.160.1 to 86.142.175.25486.142.175.2554,094
10886.142.176.0/2086.142.176.1 to 86.142.191.25486.142.191.2554,094
10986.142.192.0/2086.142.192.1 to 86.142.207.25486.142.207.2554,094
11086.142.208.0/2086.142.208.1 to 86.142.223.25486.142.223.2554,094
11186.142.224.0/2086.142.224.1 to 86.142.239.25486.142.239.2554,094
11286.142.240.0/2086.142.240.1 to 86.142.255.25486.142.255.2554,094
11386.143.0.0/2086.143.0.1 to 86.143.15.25486.143.15.2554,094
11486.143.16.0/2086.143.16.1 to 86.143.31.25486.143.31.2554,094
11586.143.32.0/2086.143.32.1 to 86.143.47.25486.143.47.2554,094
11686.143.48.0/2086.143.48.1 to 86.143.63.25486.143.63.2554,094
11786.143.64.0/2086.143.64.1 to 86.143.79.25486.143.79.2554,094
11886.143.80.0/2086.143.80.1 to 86.143.95.25486.143.95.2554,094
11986.143.96.0/2086.143.96.1 to 86.143.111.25486.143.111.2554,094
12086.143.112.0/2086.143.112.1 to 86.143.127.25486.143.127.2554,094
12186.143.128.0/2086.143.128.1 to 86.143.143.25486.143.143.2554,094
12286.143.144.0/2086.143.144.1 to 86.143.159.25486.143.159.2554,094
12386.143.160.0/2086.143.160.1 to 86.143.175.25486.143.175.2554,094
12486.143.176.0/2086.143.176.1 to 86.143.191.25486.143.191.2554,094
12586.143.192.0/2086.143.192.1 to 86.143.207.25486.143.207.2554,094
12686.143.208.0/2086.143.208.1 to 86.143.223.25486.143.223.2554,094
12786.143.224.0/2086.143.224.1 to 86.143.239.25486.143.239.2554,094
12886.143.240.0/2086.143.240.1 to 86.143.255.25486.143.255.2554,094

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.