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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.

Network84.0.0.0/6
Usable hosts67,108,862
Subnet mask252.0.0.0
Addresses67,108,864
Network address
84.0.0.0
Broadcast address
87.255.255.255
First usable
84.0.0.1
Last usable
87.255.255.254
Usable hosts
67,108,862 (67,108,864 less the network and broadcast addresses)
Subnet mask
252.0.0.0
Wildcard mask
3.255.255.255 (Cisco ACLs, OSPF)
Prefix length
/6
Type
Public public
Old class
A (default /8)
As numbers
Hex 54000000 · Integer 1409286144 to 1476395007
Reverse DNS zones
84.in-addr.arpa
85.in-addr.arpa
86.in-addr.arpa
87.in-addr.arpa
/6 is not on a 8-bit boundary, so it takes 4 /8 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address01010100.00000000.00000000.0000000084.0.0.0
Subnet mask11111100.00000000.00000000.00000000252.0.0.0
Network01010100.00000000.00000000.0000000084.0.0.0
Broadcast01010111.11111111.11111111.1111111187.255.255.255
Split into smaller subnets/13
/7 (2)/8 (4)/9 (8)/10 (16)/11 (32)/12 (64)/13 (128)/14 (256)/15 (512)/16 (1,024)/17 (2,048)/18 (4,096)

84.0.0.0/6 makes 128 subnets of /13.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
184.0.0.0/1384.0.0.1 to 84.7.255.25484.7.255.255524,286
284.8.0.0/1384.8.0.1 to 84.15.255.25484.15.255.255524,286
384.16.0.0/1384.16.0.1 to 84.23.255.25484.23.255.255524,286
484.24.0.0/1384.24.0.1 to 84.31.255.25484.31.255.255524,286
584.32.0.0/1384.32.0.1 to 84.39.255.25484.39.255.255524,286
684.40.0.0/1384.40.0.1 to 84.47.255.25484.47.255.255524,286
784.48.0.0/1384.48.0.1 to 84.55.255.25484.55.255.255524,286
884.56.0.0/1384.56.0.1 to 84.63.255.25484.63.255.255524,286
984.64.0.0/1384.64.0.1 to 84.71.255.25484.71.255.255524,286
1084.72.0.0/1384.72.0.1 to 84.79.255.25484.79.255.255524,286
1184.80.0.0/1384.80.0.1 to 84.87.255.25484.87.255.255524,286
1284.88.0.0/1384.88.0.1 to 84.95.255.25484.95.255.255524,286
1384.96.0.0/1384.96.0.1 to 84.103.255.25484.103.255.255524,286
1484.104.0.0/1384.104.0.1 to 84.111.255.25484.111.255.255524,286
1584.112.0.0/1384.112.0.1 to 84.119.255.25484.119.255.255524,286
1684.120.0.0/1384.120.0.1 to 84.127.255.25484.127.255.255524,286
1784.128.0.0/1384.128.0.1 to 84.135.255.25484.135.255.255524,286
1884.136.0.0/1384.136.0.1 to 84.143.255.25484.143.255.255524,286
1984.144.0.0/1384.144.0.1 to 84.151.255.25484.151.255.255524,286
2084.152.0.0/1384.152.0.1 to 84.159.255.25484.159.255.255524,286
2184.160.0.0/1384.160.0.1 to 84.167.255.25484.167.255.255524,286
2284.168.0.0/1384.168.0.1 to 84.175.255.25484.175.255.255524,286
2384.176.0.0/1384.176.0.1 to 84.183.255.25484.183.255.255524,286
2484.184.0.0/1384.184.0.1 to 84.191.255.25484.191.255.255524,286
2584.192.0.0/1384.192.0.1 to 84.199.255.25484.199.255.255524,286
2684.200.0.0/1384.200.0.1 to 84.207.255.25484.207.255.255524,286
2784.208.0.0/1384.208.0.1 to 84.215.255.25484.215.255.255524,286
2884.216.0.0/1384.216.0.1 to 84.223.255.25484.223.255.255524,286
2984.224.0.0/1384.224.0.1 to 84.231.255.25484.231.255.255524,286
3084.232.0.0/1384.232.0.1 to 84.239.255.25484.239.255.255524,286
3184.240.0.0/1384.240.0.1 to 84.247.255.25484.247.255.255524,286
3284.248.0.0/1384.248.0.1 to 84.255.255.25484.255.255.255524,286
3385.0.0.0/1385.0.0.1 to 85.7.255.25485.7.255.255524,286
3485.8.0.0/1385.8.0.1 to 85.15.255.25485.15.255.255524,286
3585.16.0.0/1385.16.0.1 to 85.23.255.25485.23.255.255524,286
3685.24.0.0/1385.24.0.1 to 85.31.255.25485.31.255.255524,286
3785.32.0.0/1385.32.0.1 to 85.39.255.25485.39.255.255524,286
3885.40.0.0/1385.40.0.1 to 85.47.255.25485.47.255.255524,286
3985.48.0.0/1385.48.0.1 to 85.55.255.25485.55.255.255524,286
4085.56.0.0/1385.56.0.1 to 85.63.255.25485.63.255.255524,286
4185.64.0.0/1385.64.0.1 to 85.71.255.25485.71.255.255524,286
4285.72.0.0/1385.72.0.1 to 85.79.255.25485.79.255.255524,286
4385.80.0.0/1385.80.0.1 to 85.87.255.25485.87.255.255524,286
4485.88.0.0/1385.88.0.1 to 85.95.255.25485.95.255.255524,286
4585.96.0.0/1385.96.0.1 to 85.103.255.25485.103.255.255524,286
4685.104.0.0/1385.104.0.1 to 85.111.255.25485.111.255.255524,286
4785.112.0.0/1385.112.0.1 to 85.119.255.25485.119.255.255524,286
4885.120.0.0/1385.120.0.1 to 85.127.255.25485.127.255.255524,286
4985.128.0.0/1385.128.0.1 to 85.135.255.25485.135.255.255524,286
5085.136.0.0/1385.136.0.1 to 85.143.255.25485.143.255.255524,286
5185.144.0.0/1385.144.0.1 to 85.151.255.25485.151.255.255524,286
5285.152.0.0/1385.152.0.1 to 85.159.255.25485.159.255.255524,286
5385.160.0.0/1385.160.0.1 to 85.167.255.25485.167.255.255524,286
5485.168.0.0/1385.168.0.1 to 85.175.255.25485.175.255.255524,286
5585.176.0.0/1385.176.0.1 to 85.183.255.25485.183.255.255524,286
5685.184.0.0/1385.184.0.1 to 85.191.255.25485.191.255.255524,286
5785.192.0.0/1385.192.0.1 to 85.199.255.25485.199.255.255524,286
5885.200.0.0/1385.200.0.1 to 85.207.255.25485.207.255.255524,286
5985.208.0.0/1385.208.0.1 to 85.215.255.25485.215.255.255524,286
6085.216.0.0/1385.216.0.1 to 85.223.255.25485.223.255.255524,286
6185.224.0.0/1385.224.0.1 to 85.231.255.25485.231.255.255524,286
6285.232.0.0/1385.232.0.1 to 85.239.255.25485.239.255.255524,286
6385.240.0.0/1385.240.0.1 to 85.247.255.25485.247.255.255524,286
6485.248.0.0/1385.248.0.1 to 85.255.255.25485.255.255.255524,286
6586.0.0.0/1386.0.0.1 to 86.7.255.25486.7.255.255524,286
6686.8.0.0/1386.8.0.1 to 86.15.255.25486.15.255.255524,286
6786.16.0.0/1386.16.0.1 to 86.23.255.25486.23.255.255524,286
6886.24.0.0/1386.24.0.1 to 86.31.255.25486.31.255.255524,286
6986.32.0.0/1386.32.0.1 to 86.39.255.25486.39.255.255524,286
7086.40.0.0/1386.40.0.1 to 86.47.255.25486.47.255.255524,286
7186.48.0.0/1386.48.0.1 to 86.55.255.25486.55.255.255524,286
7286.56.0.0/1386.56.0.1 to 86.63.255.25486.63.255.255524,286
7386.64.0.0/1386.64.0.1 to 86.71.255.25486.71.255.255524,286
7486.72.0.0/1386.72.0.1 to 86.79.255.25486.79.255.255524,286
7586.80.0.0/1386.80.0.1 to 86.87.255.25486.87.255.255524,286
7686.88.0.0/1386.88.0.1 to 86.95.255.25486.95.255.255524,286
7786.96.0.0/1386.96.0.1 to 86.103.255.25486.103.255.255524,286
7886.104.0.0/1386.104.0.1 to 86.111.255.25486.111.255.255524,286
7986.112.0.0/1386.112.0.1 to 86.119.255.25486.119.255.255524,286
8086.120.0.0/1386.120.0.1 to 86.127.255.25486.127.255.255524,286
8186.128.0.0/1386.128.0.1 to 86.135.255.25486.135.255.255524,286
8286.136.0.0/1386.136.0.1 to 86.143.255.25486.143.255.255524,286
8386.144.0.0/1386.144.0.1 to 86.151.255.25486.151.255.255524,286
8486.152.0.0/1386.152.0.1 to 86.159.255.25486.159.255.255524,286
8586.160.0.0/1386.160.0.1 to 86.167.255.25486.167.255.255524,286
8686.168.0.0/1386.168.0.1 to 86.175.255.25486.175.255.255524,286
8786.176.0.0/1386.176.0.1 to 86.183.255.25486.183.255.255524,286
8886.184.0.0/1386.184.0.1 to 86.191.255.25486.191.255.255524,286
8986.192.0.0/1386.192.0.1 to 86.199.255.25486.199.255.255524,286
9086.200.0.0/1386.200.0.1 to 86.207.255.25486.207.255.255524,286
9186.208.0.0/1386.208.0.1 to 86.215.255.25486.215.255.255524,286
9286.216.0.0/1386.216.0.1 to 86.223.255.25486.223.255.255524,286
9386.224.0.0/1386.224.0.1 to 86.231.255.25486.231.255.255524,286
9486.232.0.0/1386.232.0.1 to 86.239.255.25486.239.255.255524,286
9586.240.0.0/1386.240.0.1 to 86.247.255.25486.247.255.255524,286
9686.248.0.0/1386.248.0.1 to 86.255.255.25486.255.255.255524,286
9787.0.0.0/1387.0.0.1 to 87.7.255.25487.7.255.255524,286
9887.8.0.0/1387.8.0.1 to 87.15.255.25487.15.255.255524,286
9987.16.0.0/1387.16.0.1 to 87.23.255.25487.23.255.255524,286
10087.24.0.0/1387.24.0.1 to 87.31.255.25487.31.255.255524,286
10187.32.0.0/1387.32.0.1 to 87.39.255.25487.39.255.255524,286
10287.40.0.0/1387.40.0.1 to 87.47.255.25487.47.255.255524,286
10387.48.0.0/1387.48.0.1 to 87.55.255.25487.55.255.255524,286
10487.56.0.0/1387.56.0.1 to 87.63.255.25487.63.255.255524,286
10587.64.0.0/1387.64.0.1 to 87.71.255.25487.71.255.255524,286
10687.72.0.0/1387.72.0.1 to 87.79.255.25487.79.255.255524,286
10787.80.0.0/1387.80.0.1 to 87.87.255.25487.87.255.255524,286
10887.88.0.0/1387.88.0.1 to 87.95.255.25487.95.255.255524,286
10987.96.0.0/1387.96.0.1 to 87.103.255.25487.103.255.255524,286
11087.104.0.0/1387.104.0.1 to 87.111.255.25487.111.255.255524,286
11187.112.0.0/1387.112.0.1 to 87.119.255.25487.119.255.255524,286
11287.120.0.0/1387.120.0.1 to 87.127.255.25487.127.255.255524,286
11387.128.0.0/1387.128.0.1 to 87.135.255.25487.135.255.255524,286
11487.136.0.0/1387.136.0.1 to 87.143.255.25487.143.255.255524,286
11587.144.0.0/1387.144.0.1 to 87.151.255.25487.151.255.255524,286
11687.152.0.0/1387.152.0.1 to 87.159.255.25487.159.255.255524,286
11787.160.0.0/1387.160.0.1 to 87.167.255.25487.167.255.255524,286
11887.168.0.0/1387.168.0.1 to 87.175.255.25487.175.255.255524,286
11987.176.0.0/1387.176.0.1 to 87.183.255.25487.183.255.255524,286
12087.184.0.0/1387.184.0.1 to 87.191.255.25487.191.255.255524,286
12187.192.0.0/1387.192.0.1 to 87.199.255.25487.199.255.255524,286
12287.200.0.0/1387.200.0.1 to 87.207.255.25487.207.255.255524,286
12387.208.0.0/1387.208.0.1 to 87.215.255.25487.215.255.255524,286
12487.216.0.0/1387.216.0.1 to 87.223.255.25487.223.255.255524,286
12587.224.0.0/1387.224.0.1 to 87.231.255.25487.231.255.255524,286
12687.232.0.0/1387.232.0.1 to 87.239.255.25487.239.255.255524,286
12787.240.0.0/1387.240.0.1 to 87.247.255.25487.247.255.255524,286
12887.248.0.0/1387.248.0.1 to 87.255.255.25487.255.255.255524,286

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.