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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.

Network80.136.0.0/14
Usable hosts262,142
Subnet mask255.252.0.0
Addresses262,144
Network address
80.136.0.0
Broadcast address
80.139.255.255
First usable
80.136.0.1
Last usable
80.139.255.254
Usable hosts
262,142 (262,144 less the network and broadcast addresses)
Subnet mask
255.252.0.0
Wildcard mask
0.3.255.255 (Cisco ACLs, OSPF)
Prefix length
/14
Type
Public public
Old class
A (default /8)
As numbers
Hex 50880000 · Integer 1351090176 to 1351352319
Reverse DNS zones
136.80.in-addr.arpa
137.80.in-addr.arpa
138.80.in-addr.arpa
139.80.in-addr.arpa
/14 is not on a 8-bit boundary, so it takes 4 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address01010000.10001000.00000000.0000000080.136.0.0
Subnet mask11111111.11111100.00000000.00000000255.252.0.0
Network01010000.10001000.00000000.0000000080.136.0.0
Broadcast01010000.10001011.11111111.1111111180.139.255.255
Split into smaller subnets/21
/15 (2)/16 (4)/17 (8)/18 (16)/19 (32)/20 (64)/21 (128)/22 (256)/23 (512)/24 (1,024)/25 (2,048)/26 (4,096)

80.136.0.0/14 makes 128 subnets of /21.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
180.136.0.0/2180.136.0.1 to 80.136.7.25480.136.7.2552,046
280.136.8.0/2180.136.8.1 to 80.136.15.25480.136.15.2552,046
380.136.16.0/2180.136.16.1 to 80.136.23.25480.136.23.2552,046
480.136.24.0/2180.136.24.1 to 80.136.31.25480.136.31.2552,046
580.136.32.0/2180.136.32.1 to 80.136.39.25480.136.39.2552,046
680.136.40.0/2180.136.40.1 to 80.136.47.25480.136.47.2552,046
780.136.48.0/2180.136.48.1 to 80.136.55.25480.136.55.2552,046
880.136.56.0/2180.136.56.1 to 80.136.63.25480.136.63.2552,046
980.136.64.0/2180.136.64.1 to 80.136.71.25480.136.71.2552,046
1080.136.72.0/2180.136.72.1 to 80.136.79.25480.136.79.2552,046
1180.136.80.0/2180.136.80.1 to 80.136.87.25480.136.87.2552,046
1280.136.88.0/2180.136.88.1 to 80.136.95.25480.136.95.2552,046
1380.136.96.0/2180.136.96.1 to 80.136.103.25480.136.103.2552,046
1480.136.104.0/2180.136.104.1 to 80.136.111.25480.136.111.2552,046
1580.136.112.0/2180.136.112.1 to 80.136.119.25480.136.119.2552,046
1680.136.120.0/2180.136.120.1 to 80.136.127.25480.136.127.2552,046
1780.136.128.0/2180.136.128.1 to 80.136.135.25480.136.135.2552,046
1880.136.136.0/2180.136.136.1 to 80.136.143.25480.136.143.2552,046
1980.136.144.0/2180.136.144.1 to 80.136.151.25480.136.151.2552,046
2080.136.152.0/2180.136.152.1 to 80.136.159.25480.136.159.2552,046
2180.136.160.0/2180.136.160.1 to 80.136.167.25480.136.167.2552,046
2280.136.168.0/2180.136.168.1 to 80.136.175.25480.136.175.2552,046
2380.136.176.0/2180.136.176.1 to 80.136.183.25480.136.183.2552,046
2480.136.184.0/2180.136.184.1 to 80.136.191.25480.136.191.2552,046
2580.136.192.0/2180.136.192.1 to 80.136.199.25480.136.199.2552,046
2680.136.200.0/2180.136.200.1 to 80.136.207.25480.136.207.2552,046
2780.136.208.0/2180.136.208.1 to 80.136.215.25480.136.215.2552,046
2880.136.216.0/2180.136.216.1 to 80.136.223.25480.136.223.2552,046
2980.136.224.0/2180.136.224.1 to 80.136.231.25480.136.231.2552,046
3080.136.232.0/2180.136.232.1 to 80.136.239.25480.136.239.2552,046
3180.136.240.0/2180.136.240.1 to 80.136.247.25480.136.247.2552,046
3280.136.248.0/2180.136.248.1 to 80.136.255.25480.136.255.2552,046
3380.137.0.0/2180.137.0.1 to 80.137.7.25480.137.7.2552,046
3480.137.8.0/2180.137.8.1 to 80.137.15.25480.137.15.2552,046
3580.137.16.0/2180.137.16.1 to 80.137.23.25480.137.23.2552,046
3680.137.24.0/2180.137.24.1 to 80.137.31.25480.137.31.2552,046
3780.137.32.0/2180.137.32.1 to 80.137.39.25480.137.39.2552,046
3880.137.40.0/2180.137.40.1 to 80.137.47.25480.137.47.2552,046
3980.137.48.0/2180.137.48.1 to 80.137.55.25480.137.55.2552,046
4080.137.56.0/2180.137.56.1 to 80.137.63.25480.137.63.2552,046
4180.137.64.0/2180.137.64.1 to 80.137.71.25480.137.71.2552,046
4280.137.72.0/2180.137.72.1 to 80.137.79.25480.137.79.2552,046
4380.137.80.0/2180.137.80.1 to 80.137.87.25480.137.87.2552,046
4480.137.88.0/2180.137.88.1 to 80.137.95.25480.137.95.2552,046
4580.137.96.0/2180.137.96.1 to 80.137.103.25480.137.103.2552,046
4680.137.104.0/2180.137.104.1 to 80.137.111.25480.137.111.2552,046
4780.137.112.0/2180.137.112.1 to 80.137.119.25480.137.119.2552,046
4880.137.120.0/2180.137.120.1 to 80.137.127.25480.137.127.2552,046
4980.137.128.0/2180.137.128.1 to 80.137.135.25480.137.135.2552,046
5080.137.136.0/2180.137.136.1 to 80.137.143.25480.137.143.2552,046
5180.137.144.0/2180.137.144.1 to 80.137.151.25480.137.151.2552,046
5280.137.152.0/2180.137.152.1 to 80.137.159.25480.137.159.2552,046
5380.137.160.0/2180.137.160.1 to 80.137.167.25480.137.167.2552,046
5480.137.168.0/2180.137.168.1 to 80.137.175.25480.137.175.2552,046
5580.137.176.0/2180.137.176.1 to 80.137.183.25480.137.183.2552,046
5680.137.184.0/2180.137.184.1 to 80.137.191.25480.137.191.2552,046
5780.137.192.0/2180.137.192.1 to 80.137.199.25480.137.199.2552,046
5880.137.200.0/2180.137.200.1 to 80.137.207.25480.137.207.2552,046
5980.137.208.0/2180.137.208.1 to 80.137.215.25480.137.215.2552,046
6080.137.216.0/2180.137.216.1 to 80.137.223.25480.137.223.2552,046
6180.137.224.0/2180.137.224.1 to 80.137.231.25480.137.231.2552,046
6280.137.232.0/2180.137.232.1 to 80.137.239.25480.137.239.2552,046
6380.137.240.0/2180.137.240.1 to 80.137.247.25480.137.247.2552,046
6480.137.248.0/2180.137.248.1 to 80.137.255.25480.137.255.2552,046
6580.138.0.0/2180.138.0.1 to 80.138.7.25480.138.7.2552,046
6680.138.8.0/2180.138.8.1 to 80.138.15.25480.138.15.2552,046
6780.138.16.0/2180.138.16.1 to 80.138.23.25480.138.23.2552,046
6880.138.24.0/2180.138.24.1 to 80.138.31.25480.138.31.2552,046
6980.138.32.0/2180.138.32.1 to 80.138.39.25480.138.39.2552,046
7080.138.40.0/2180.138.40.1 to 80.138.47.25480.138.47.2552,046
7180.138.48.0/2180.138.48.1 to 80.138.55.25480.138.55.2552,046
7280.138.56.0/2180.138.56.1 to 80.138.63.25480.138.63.2552,046
7380.138.64.0/2180.138.64.1 to 80.138.71.25480.138.71.2552,046
7480.138.72.0/2180.138.72.1 to 80.138.79.25480.138.79.2552,046
7580.138.80.0/2180.138.80.1 to 80.138.87.25480.138.87.2552,046
7680.138.88.0/2180.138.88.1 to 80.138.95.25480.138.95.2552,046
7780.138.96.0/2180.138.96.1 to 80.138.103.25480.138.103.2552,046
7880.138.104.0/2180.138.104.1 to 80.138.111.25480.138.111.2552,046
7980.138.112.0/2180.138.112.1 to 80.138.119.25480.138.119.2552,046
8080.138.120.0/2180.138.120.1 to 80.138.127.25480.138.127.2552,046
8180.138.128.0/2180.138.128.1 to 80.138.135.25480.138.135.2552,046
8280.138.136.0/2180.138.136.1 to 80.138.143.25480.138.143.2552,046
8380.138.144.0/2180.138.144.1 to 80.138.151.25480.138.151.2552,046
8480.138.152.0/2180.138.152.1 to 80.138.159.25480.138.159.2552,046
8580.138.160.0/2180.138.160.1 to 80.138.167.25480.138.167.2552,046
8680.138.168.0/2180.138.168.1 to 80.138.175.25480.138.175.2552,046
8780.138.176.0/2180.138.176.1 to 80.138.183.25480.138.183.2552,046
8880.138.184.0/2180.138.184.1 to 80.138.191.25480.138.191.2552,046
8980.138.192.0/2180.138.192.1 to 80.138.199.25480.138.199.2552,046
9080.138.200.0/2180.138.200.1 to 80.138.207.25480.138.207.2552,046
9180.138.208.0/2180.138.208.1 to 80.138.215.25480.138.215.2552,046
9280.138.216.0/2180.138.216.1 to 80.138.223.25480.138.223.2552,046
9380.138.224.0/2180.138.224.1 to 80.138.231.25480.138.231.2552,046
9480.138.232.0/2180.138.232.1 to 80.138.239.25480.138.239.2552,046
9580.138.240.0/2180.138.240.1 to 80.138.247.25480.138.247.2552,046
9680.138.248.0/2180.138.248.1 to 80.138.255.25480.138.255.2552,046
9780.139.0.0/2180.139.0.1 to 80.139.7.25480.139.7.2552,046
9880.139.8.0/2180.139.8.1 to 80.139.15.25480.139.15.2552,046
9980.139.16.0/2180.139.16.1 to 80.139.23.25480.139.23.2552,046
10080.139.24.0/2180.139.24.1 to 80.139.31.25480.139.31.2552,046
10180.139.32.0/2180.139.32.1 to 80.139.39.25480.139.39.2552,046
10280.139.40.0/2180.139.40.1 to 80.139.47.25480.139.47.2552,046
10380.139.48.0/2180.139.48.1 to 80.139.55.25480.139.55.2552,046
10480.139.56.0/2180.139.56.1 to 80.139.63.25480.139.63.2552,046
10580.139.64.0/2180.139.64.1 to 80.139.71.25480.139.71.2552,046
10680.139.72.0/2180.139.72.1 to 80.139.79.25480.139.79.2552,046
10780.139.80.0/2180.139.80.1 to 80.139.87.25480.139.87.2552,046
10880.139.88.0/2180.139.88.1 to 80.139.95.25480.139.95.2552,046
10980.139.96.0/2180.139.96.1 to 80.139.103.25480.139.103.2552,046
11080.139.104.0/2180.139.104.1 to 80.139.111.25480.139.111.2552,046
11180.139.112.0/2180.139.112.1 to 80.139.119.25480.139.119.2552,046
11280.139.120.0/2180.139.120.1 to 80.139.127.25480.139.127.2552,046
11380.139.128.0/2180.139.128.1 to 80.139.135.25480.139.135.2552,046
11480.139.136.0/2180.139.136.1 to 80.139.143.25480.139.143.2552,046
11580.139.144.0/2180.139.144.1 to 80.139.151.25480.139.151.2552,046
11680.139.152.0/2180.139.152.1 to 80.139.159.25480.139.159.2552,046
11780.139.160.0/2180.139.160.1 to 80.139.167.25480.139.167.2552,046
11880.139.168.0/2180.139.168.1 to 80.139.175.25480.139.175.2552,046
11980.139.176.0/2180.139.176.1 to 80.139.183.25480.139.183.2552,046
12080.139.184.0/2180.139.184.1 to 80.139.191.25480.139.191.2552,046
12180.139.192.0/2180.139.192.1 to 80.139.199.25480.139.199.2552,046
12280.139.200.0/2180.139.200.1 to 80.139.207.25480.139.207.2552,046
12380.139.208.0/2180.139.208.1 to 80.139.215.25480.139.215.2552,046
12480.139.216.0/2180.139.216.1 to 80.139.223.25480.139.223.2552,046
12580.139.224.0/2180.139.224.1 to 80.139.231.25480.139.231.2552,046
12680.139.232.0/2180.139.232.1 to 80.139.239.25480.139.239.2552,046
12780.139.240.0/2180.139.240.1 to 80.139.247.25480.139.247.2552,046
12880.139.248.0/2180.139.248.1 to 80.139.255.25480.139.255.2552,046

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.