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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.

Network96.0.0.0/6
Usable hosts67,108,862
Subnet mask252.0.0.0
Addresses67,108,864
Network address
96.0.0.0
Broadcast address
99.255.255.255
First usable
96.0.0.1
Last usable
99.255.255.254
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 60000000 · Integer 1610612736 to 1677721599
Reverse DNS zones
96.in-addr.arpa
97.in-addr.arpa
98.in-addr.arpa
99.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
Address01100000.00000000.00000000.0000000096.0.0.0
Subnet mask11111100.00000000.00000000.00000000252.0.0.0
Network01100000.00000000.00000000.0000000096.0.0.0
Broadcast01100011.11111111.11111111.1111111199.255.255.255
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)

96.0.0.0/6 makes 128 subnets of /13.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
196.0.0.0/1396.0.0.1 to 96.7.255.25496.7.255.255524,286
296.8.0.0/1396.8.0.1 to 96.15.255.25496.15.255.255524,286
396.16.0.0/1396.16.0.1 to 96.23.255.25496.23.255.255524,286
496.24.0.0/1396.24.0.1 to 96.31.255.25496.31.255.255524,286
596.32.0.0/1396.32.0.1 to 96.39.255.25496.39.255.255524,286
696.40.0.0/1396.40.0.1 to 96.47.255.25496.47.255.255524,286
796.48.0.0/1396.48.0.1 to 96.55.255.25496.55.255.255524,286
896.56.0.0/1396.56.0.1 to 96.63.255.25496.63.255.255524,286
996.64.0.0/1396.64.0.1 to 96.71.255.25496.71.255.255524,286
1096.72.0.0/1396.72.0.1 to 96.79.255.25496.79.255.255524,286
1196.80.0.0/1396.80.0.1 to 96.87.255.25496.87.255.255524,286
1296.88.0.0/1396.88.0.1 to 96.95.255.25496.95.255.255524,286
1396.96.0.0/1396.96.0.1 to 96.103.255.25496.103.255.255524,286
1496.104.0.0/1396.104.0.1 to 96.111.255.25496.111.255.255524,286
1596.112.0.0/1396.112.0.1 to 96.119.255.25496.119.255.255524,286
1696.120.0.0/1396.120.0.1 to 96.127.255.25496.127.255.255524,286
1796.128.0.0/1396.128.0.1 to 96.135.255.25496.135.255.255524,286
1896.136.0.0/1396.136.0.1 to 96.143.255.25496.143.255.255524,286
1996.144.0.0/1396.144.0.1 to 96.151.255.25496.151.255.255524,286
2096.152.0.0/1396.152.0.1 to 96.159.255.25496.159.255.255524,286
2196.160.0.0/1396.160.0.1 to 96.167.255.25496.167.255.255524,286
2296.168.0.0/1396.168.0.1 to 96.175.255.25496.175.255.255524,286
2396.176.0.0/1396.176.0.1 to 96.183.255.25496.183.255.255524,286
2496.184.0.0/1396.184.0.1 to 96.191.255.25496.191.255.255524,286
2596.192.0.0/1396.192.0.1 to 96.199.255.25496.199.255.255524,286
2696.200.0.0/1396.200.0.1 to 96.207.255.25496.207.255.255524,286
2796.208.0.0/1396.208.0.1 to 96.215.255.25496.215.255.255524,286
2896.216.0.0/1396.216.0.1 to 96.223.255.25496.223.255.255524,286
2996.224.0.0/1396.224.0.1 to 96.231.255.25496.231.255.255524,286
3096.232.0.0/1396.232.0.1 to 96.239.255.25496.239.255.255524,286
3196.240.0.0/1396.240.0.1 to 96.247.255.25496.247.255.255524,286
3296.248.0.0/1396.248.0.1 to 96.255.255.25496.255.255.255524,286
3397.0.0.0/1397.0.0.1 to 97.7.255.25497.7.255.255524,286
3497.8.0.0/1397.8.0.1 to 97.15.255.25497.15.255.255524,286
3597.16.0.0/1397.16.0.1 to 97.23.255.25497.23.255.255524,286
3697.24.0.0/1397.24.0.1 to 97.31.255.25497.31.255.255524,286
3797.32.0.0/1397.32.0.1 to 97.39.255.25497.39.255.255524,286
3897.40.0.0/1397.40.0.1 to 97.47.255.25497.47.255.255524,286
3997.48.0.0/1397.48.0.1 to 97.55.255.25497.55.255.255524,286
4097.56.0.0/1397.56.0.1 to 97.63.255.25497.63.255.255524,286
4197.64.0.0/1397.64.0.1 to 97.71.255.25497.71.255.255524,286
4297.72.0.0/1397.72.0.1 to 97.79.255.25497.79.255.255524,286
4397.80.0.0/1397.80.0.1 to 97.87.255.25497.87.255.255524,286
4497.88.0.0/1397.88.0.1 to 97.95.255.25497.95.255.255524,286
4597.96.0.0/1397.96.0.1 to 97.103.255.25497.103.255.255524,286
4697.104.0.0/1397.104.0.1 to 97.111.255.25497.111.255.255524,286
4797.112.0.0/1397.112.0.1 to 97.119.255.25497.119.255.255524,286
4897.120.0.0/1397.120.0.1 to 97.127.255.25497.127.255.255524,286
4997.128.0.0/1397.128.0.1 to 97.135.255.25497.135.255.255524,286
5097.136.0.0/1397.136.0.1 to 97.143.255.25497.143.255.255524,286
5197.144.0.0/1397.144.0.1 to 97.151.255.25497.151.255.255524,286
5297.152.0.0/1397.152.0.1 to 97.159.255.25497.159.255.255524,286
5397.160.0.0/1397.160.0.1 to 97.167.255.25497.167.255.255524,286
5497.168.0.0/1397.168.0.1 to 97.175.255.25497.175.255.255524,286
5597.176.0.0/1397.176.0.1 to 97.183.255.25497.183.255.255524,286
5697.184.0.0/1397.184.0.1 to 97.191.255.25497.191.255.255524,286
5797.192.0.0/1397.192.0.1 to 97.199.255.25497.199.255.255524,286
5897.200.0.0/1397.200.0.1 to 97.207.255.25497.207.255.255524,286
5997.208.0.0/1397.208.0.1 to 97.215.255.25497.215.255.255524,286
6097.216.0.0/1397.216.0.1 to 97.223.255.25497.223.255.255524,286
6197.224.0.0/1397.224.0.1 to 97.231.255.25497.231.255.255524,286
6297.232.0.0/1397.232.0.1 to 97.239.255.25497.239.255.255524,286
6397.240.0.0/1397.240.0.1 to 97.247.255.25497.247.255.255524,286
6497.248.0.0/1397.248.0.1 to 97.255.255.25497.255.255.255524,286
6598.0.0.0/1398.0.0.1 to 98.7.255.25498.7.255.255524,286
6698.8.0.0/1398.8.0.1 to 98.15.255.25498.15.255.255524,286
6798.16.0.0/1398.16.0.1 to 98.23.255.25498.23.255.255524,286
6898.24.0.0/1398.24.0.1 to 98.31.255.25498.31.255.255524,286
6998.32.0.0/1398.32.0.1 to 98.39.255.25498.39.255.255524,286
7098.40.0.0/1398.40.0.1 to 98.47.255.25498.47.255.255524,286
7198.48.0.0/1398.48.0.1 to 98.55.255.25498.55.255.255524,286
7298.56.0.0/1398.56.0.1 to 98.63.255.25498.63.255.255524,286
7398.64.0.0/1398.64.0.1 to 98.71.255.25498.71.255.255524,286
7498.72.0.0/1398.72.0.1 to 98.79.255.25498.79.255.255524,286
7598.80.0.0/1398.80.0.1 to 98.87.255.25498.87.255.255524,286
7698.88.0.0/1398.88.0.1 to 98.95.255.25498.95.255.255524,286
7798.96.0.0/1398.96.0.1 to 98.103.255.25498.103.255.255524,286
7898.104.0.0/1398.104.0.1 to 98.111.255.25498.111.255.255524,286
7998.112.0.0/1398.112.0.1 to 98.119.255.25498.119.255.255524,286
8098.120.0.0/1398.120.0.1 to 98.127.255.25498.127.255.255524,286
8198.128.0.0/1398.128.0.1 to 98.135.255.25498.135.255.255524,286
8298.136.0.0/1398.136.0.1 to 98.143.255.25498.143.255.255524,286
8398.144.0.0/1398.144.0.1 to 98.151.255.25498.151.255.255524,286
8498.152.0.0/1398.152.0.1 to 98.159.255.25498.159.255.255524,286
8598.160.0.0/1398.160.0.1 to 98.167.255.25498.167.255.255524,286
8698.168.0.0/1398.168.0.1 to 98.175.255.25498.175.255.255524,286
8798.176.0.0/1398.176.0.1 to 98.183.255.25498.183.255.255524,286
8898.184.0.0/1398.184.0.1 to 98.191.255.25498.191.255.255524,286
8998.192.0.0/1398.192.0.1 to 98.199.255.25498.199.255.255524,286
9098.200.0.0/1398.200.0.1 to 98.207.255.25498.207.255.255524,286
9198.208.0.0/1398.208.0.1 to 98.215.255.25498.215.255.255524,286
9298.216.0.0/1398.216.0.1 to 98.223.255.25498.223.255.255524,286
9398.224.0.0/1398.224.0.1 to 98.231.255.25498.231.255.255524,286
9498.232.0.0/1398.232.0.1 to 98.239.255.25498.239.255.255524,286
9598.240.0.0/1398.240.0.1 to 98.247.255.25498.247.255.255524,286
9698.248.0.0/1398.248.0.1 to 98.255.255.25498.255.255.255524,286
9799.0.0.0/1399.0.0.1 to 99.7.255.25499.7.255.255524,286
9899.8.0.0/1399.8.0.1 to 99.15.255.25499.15.255.255524,286
9999.16.0.0/1399.16.0.1 to 99.23.255.25499.23.255.255524,286
10099.24.0.0/1399.24.0.1 to 99.31.255.25499.31.255.255524,286
10199.32.0.0/1399.32.0.1 to 99.39.255.25499.39.255.255524,286
10299.40.0.0/1399.40.0.1 to 99.47.255.25499.47.255.255524,286
10399.48.0.0/1399.48.0.1 to 99.55.255.25499.55.255.255524,286
10499.56.0.0/1399.56.0.1 to 99.63.255.25499.63.255.255524,286
10599.64.0.0/1399.64.0.1 to 99.71.255.25499.71.255.255524,286
10699.72.0.0/1399.72.0.1 to 99.79.255.25499.79.255.255524,286
10799.80.0.0/1399.80.0.1 to 99.87.255.25499.87.255.255524,286
10899.88.0.0/1399.88.0.1 to 99.95.255.25499.95.255.255524,286
10999.96.0.0/1399.96.0.1 to 99.103.255.25499.103.255.255524,286
11099.104.0.0/1399.104.0.1 to 99.111.255.25499.111.255.255524,286
11199.112.0.0/1399.112.0.1 to 99.119.255.25499.119.255.255524,286
11299.120.0.0/1399.120.0.1 to 99.127.255.25499.127.255.255524,286
11399.128.0.0/1399.128.0.1 to 99.135.255.25499.135.255.255524,286
11499.136.0.0/1399.136.0.1 to 99.143.255.25499.143.255.255524,286
11599.144.0.0/1399.144.0.1 to 99.151.255.25499.151.255.255524,286
11699.152.0.0/1399.152.0.1 to 99.159.255.25499.159.255.255524,286
11799.160.0.0/1399.160.0.1 to 99.167.255.25499.167.255.255524,286
11899.168.0.0/1399.168.0.1 to 99.175.255.25499.175.255.255524,286
11999.176.0.0/1399.176.0.1 to 99.183.255.25499.183.255.255524,286
12099.184.0.0/1399.184.0.1 to 99.191.255.25499.191.255.255524,286
12199.192.0.0/1399.192.0.1 to 99.199.255.25499.199.255.255524,286
12299.200.0.0/1399.200.0.1 to 99.207.255.25499.207.255.255524,286
12399.208.0.0/1399.208.0.1 to 99.215.255.25499.215.255.255524,286
12499.216.0.0/1399.216.0.1 to 99.223.255.25499.223.255.255524,286
12599.224.0.0/1399.224.0.1 to 99.231.255.25499.231.255.255524,286
12699.232.0.0/1399.232.0.1 to 99.239.255.25499.239.255.255524,286
12799.240.0.0/1399.240.0.1 to 99.247.255.25499.247.255.255524,286
12899.248.0.0/1399.248.0.1 to 99.255.255.25499.255.255.255524,286

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.