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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.

Network91.78.0.0/16
Usable hosts65,534
Subnet mask255.255.0.0
Addresses65,536
Network address
91.78.0.0
Broadcast address
91.78.255.255
First usable
91.78.0.1
Last usable
91.78.255.254
Usable hosts
65,534 (65,536 less the network and broadcast addresses)
Subnet mask
255.255.0.0
Wildcard mask
0.0.255.255 (Cisco ACLs, OSPF)
Prefix length
/16
Type
Public public
Old class
A (default /8)
As numbers
Hex 5B4E0000 · Integer 1531838464 to 1531903999
Reverse DNS zone
78.91.in-addr.arpa
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address01011011.01001110..00000000.0000000091.78.0.0
Subnet mask11111111.11111111..00000000.00000000255.255.0.0
Network01011011.01001110..00000000.0000000091.78.0.0
Broadcast01011011.01001110..11111111.1111111191.78.255.255
Split into smaller subnets/23

91.78.0.0/16 makes 128 subnets of /23.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
191.78.0.0/2391.78.0.1 to 91.78.1.25491.78.1.255510
291.78.2.0/2391.78.2.1 to 91.78.3.25491.78.3.255510
391.78.4.0/2391.78.4.1 to 91.78.5.25491.78.5.255510
491.78.6.0/2391.78.6.1 to 91.78.7.25491.78.7.255510
591.78.8.0/2391.78.8.1 to 91.78.9.25491.78.9.255510
691.78.10.0/2391.78.10.1 to 91.78.11.25491.78.11.255510
791.78.12.0/2391.78.12.1 to 91.78.13.25491.78.13.255510
891.78.14.0/2391.78.14.1 to 91.78.15.25491.78.15.255510
991.78.16.0/2391.78.16.1 to 91.78.17.25491.78.17.255510
1091.78.18.0/2391.78.18.1 to 91.78.19.25491.78.19.255510
1191.78.20.0/2391.78.20.1 to 91.78.21.25491.78.21.255510
1291.78.22.0/2391.78.22.1 to 91.78.23.25491.78.23.255510
1391.78.24.0/2391.78.24.1 to 91.78.25.25491.78.25.255510
1491.78.26.0/2391.78.26.1 to 91.78.27.25491.78.27.255510
1591.78.28.0/2391.78.28.1 to 91.78.29.25491.78.29.255510
1691.78.30.0/2391.78.30.1 to 91.78.31.25491.78.31.255510
1791.78.32.0/2391.78.32.1 to 91.78.33.25491.78.33.255510
1891.78.34.0/2391.78.34.1 to 91.78.35.25491.78.35.255510
1991.78.36.0/2391.78.36.1 to 91.78.37.25491.78.37.255510
2091.78.38.0/2391.78.38.1 to 91.78.39.25491.78.39.255510
2191.78.40.0/2391.78.40.1 to 91.78.41.25491.78.41.255510
2291.78.42.0/2391.78.42.1 to 91.78.43.25491.78.43.255510
2391.78.44.0/2391.78.44.1 to 91.78.45.25491.78.45.255510
2491.78.46.0/2391.78.46.1 to 91.78.47.25491.78.47.255510
2591.78.48.0/2391.78.48.1 to 91.78.49.25491.78.49.255510
2691.78.50.0/2391.78.50.1 to 91.78.51.25491.78.51.255510
2791.78.52.0/2391.78.52.1 to 91.78.53.25491.78.53.255510
2891.78.54.0/2391.78.54.1 to 91.78.55.25491.78.55.255510
2991.78.56.0/2391.78.56.1 to 91.78.57.25491.78.57.255510
3091.78.58.0/2391.78.58.1 to 91.78.59.25491.78.59.255510
3191.78.60.0/2391.78.60.1 to 91.78.61.25491.78.61.255510
3291.78.62.0/2391.78.62.1 to 91.78.63.25491.78.63.255510
3391.78.64.0/2391.78.64.1 to 91.78.65.25491.78.65.255510
3491.78.66.0/2391.78.66.1 to 91.78.67.25491.78.67.255510
3591.78.68.0/2391.78.68.1 to 91.78.69.25491.78.69.255510
3691.78.70.0/2391.78.70.1 to 91.78.71.25491.78.71.255510
3791.78.72.0/2391.78.72.1 to 91.78.73.25491.78.73.255510
3891.78.74.0/2391.78.74.1 to 91.78.75.25491.78.75.255510
3991.78.76.0/2391.78.76.1 to 91.78.77.25491.78.77.255510
4091.78.78.0/2391.78.78.1 to 91.78.79.25491.78.79.255510
4191.78.80.0/2391.78.80.1 to 91.78.81.25491.78.81.255510
4291.78.82.0/2391.78.82.1 to 91.78.83.25491.78.83.255510
4391.78.84.0/2391.78.84.1 to 91.78.85.25491.78.85.255510
4491.78.86.0/2391.78.86.1 to 91.78.87.25491.78.87.255510
4591.78.88.0/2391.78.88.1 to 91.78.89.25491.78.89.255510
4691.78.90.0/2391.78.90.1 to 91.78.91.25491.78.91.255510
4791.78.92.0/2391.78.92.1 to 91.78.93.25491.78.93.255510
4891.78.94.0/2391.78.94.1 to 91.78.95.25491.78.95.255510
4991.78.96.0/2391.78.96.1 to 91.78.97.25491.78.97.255510
5091.78.98.0/2391.78.98.1 to 91.78.99.25491.78.99.255510
5191.78.100.0/2391.78.100.1 to 91.78.101.25491.78.101.255510
5291.78.102.0/2391.78.102.1 to 91.78.103.25491.78.103.255510
5391.78.104.0/2391.78.104.1 to 91.78.105.25491.78.105.255510
5491.78.106.0/2391.78.106.1 to 91.78.107.25491.78.107.255510
5591.78.108.0/2391.78.108.1 to 91.78.109.25491.78.109.255510
5691.78.110.0/2391.78.110.1 to 91.78.111.25491.78.111.255510
5791.78.112.0/2391.78.112.1 to 91.78.113.25491.78.113.255510
5891.78.114.0/2391.78.114.1 to 91.78.115.25491.78.115.255510
5991.78.116.0/2391.78.116.1 to 91.78.117.25491.78.117.255510
6091.78.118.0/2391.78.118.1 to 91.78.119.25491.78.119.255510
6191.78.120.0/2391.78.120.1 to 91.78.121.25491.78.121.255510
6291.78.122.0/2391.78.122.1 to 91.78.123.25491.78.123.255510
6391.78.124.0/2391.78.124.1 to 91.78.125.25491.78.125.255510
6491.78.126.0/2391.78.126.1 to 91.78.127.25491.78.127.255510
6591.78.128.0/2391.78.128.1 to 91.78.129.25491.78.129.255510
6691.78.130.0/2391.78.130.1 to 91.78.131.25491.78.131.255510
6791.78.132.0/2391.78.132.1 to 91.78.133.25491.78.133.255510
6891.78.134.0/2391.78.134.1 to 91.78.135.25491.78.135.255510
6991.78.136.0/2391.78.136.1 to 91.78.137.25491.78.137.255510
7091.78.138.0/2391.78.138.1 to 91.78.139.25491.78.139.255510
7191.78.140.0/2391.78.140.1 to 91.78.141.25491.78.141.255510
7291.78.142.0/2391.78.142.1 to 91.78.143.25491.78.143.255510
7391.78.144.0/2391.78.144.1 to 91.78.145.25491.78.145.255510
7491.78.146.0/2391.78.146.1 to 91.78.147.25491.78.147.255510
7591.78.148.0/2391.78.148.1 to 91.78.149.25491.78.149.255510
7691.78.150.0/2391.78.150.1 to 91.78.151.25491.78.151.255510
7791.78.152.0/2391.78.152.1 to 91.78.153.25491.78.153.255510
7891.78.154.0/2391.78.154.1 to 91.78.155.25491.78.155.255510
7991.78.156.0/2391.78.156.1 to 91.78.157.25491.78.157.255510
8091.78.158.0/2391.78.158.1 to 91.78.159.25491.78.159.255510
8191.78.160.0/2391.78.160.1 to 91.78.161.25491.78.161.255510
8291.78.162.0/2391.78.162.1 to 91.78.163.25491.78.163.255510
8391.78.164.0/2391.78.164.1 to 91.78.165.25491.78.165.255510
8491.78.166.0/2391.78.166.1 to 91.78.167.25491.78.167.255510
8591.78.168.0/2391.78.168.1 to 91.78.169.25491.78.169.255510
8691.78.170.0/2391.78.170.1 to 91.78.171.25491.78.171.255510
8791.78.172.0/2391.78.172.1 to 91.78.173.25491.78.173.255510
8891.78.174.0/2391.78.174.1 to 91.78.175.25491.78.175.255510
8991.78.176.0/2391.78.176.1 to 91.78.177.25491.78.177.255510
9091.78.178.0/2391.78.178.1 to 91.78.179.25491.78.179.255510
9191.78.180.0/2391.78.180.1 to 91.78.181.25491.78.181.255510
9291.78.182.0/2391.78.182.1 to 91.78.183.25491.78.183.255510
9391.78.184.0/2391.78.184.1 to 91.78.185.25491.78.185.255510
9491.78.186.0/2391.78.186.1 to 91.78.187.25491.78.187.255510
9591.78.188.0/2391.78.188.1 to 91.78.189.25491.78.189.255510
9691.78.190.0/2391.78.190.1 to 91.78.191.25491.78.191.255510
9791.78.192.0/2391.78.192.1 to 91.78.193.25491.78.193.255510
9891.78.194.0/2391.78.194.1 to 91.78.195.25491.78.195.255510
9991.78.196.0/2391.78.196.1 to 91.78.197.25491.78.197.255510
10091.78.198.0/2391.78.198.1 to 91.78.199.25491.78.199.255510
10191.78.200.0/2391.78.200.1 to 91.78.201.25491.78.201.255510
10291.78.202.0/2391.78.202.1 to 91.78.203.25491.78.203.255510
10391.78.204.0/2391.78.204.1 to 91.78.205.25491.78.205.255510
10491.78.206.0/2391.78.206.1 to 91.78.207.25491.78.207.255510
10591.78.208.0/2391.78.208.1 to 91.78.209.25491.78.209.255510
10691.78.210.0/2391.78.210.1 to 91.78.211.25491.78.211.255510
10791.78.212.0/2391.78.212.1 to 91.78.213.25491.78.213.255510
10891.78.214.0/2391.78.214.1 to 91.78.215.25491.78.215.255510
10991.78.216.0/2391.78.216.1 to 91.78.217.25491.78.217.255510
11091.78.218.0/2391.78.218.1 to 91.78.219.25491.78.219.255510
11191.78.220.0/2391.78.220.1 to 91.78.221.25491.78.221.255510
11291.78.222.0/2391.78.222.1 to 91.78.223.25491.78.223.255510
11391.78.224.0/2391.78.224.1 to 91.78.225.25491.78.225.255510
11491.78.226.0/2391.78.226.1 to 91.78.227.25491.78.227.255510
11591.78.228.0/2391.78.228.1 to 91.78.229.25491.78.229.255510
11691.78.230.0/2391.78.230.1 to 91.78.231.25491.78.231.255510
11791.78.232.0/2391.78.232.1 to 91.78.233.25491.78.233.255510
11891.78.234.0/2391.78.234.1 to 91.78.235.25491.78.235.255510
11991.78.236.0/2391.78.236.1 to 91.78.237.25491.78.237.255510
12091.78.238.0/2391.78.238.1 to 91.78.239.25491.78.239.255510
12191.78.240.0/2391.78.240.1 to 91.78.241.25491.78.241.255510
12291.78.242.0/2391.78.242.1 to 91.78.243.25491.78.243.255510
12391.78.244.0/2391.78.244.1 to 91.78.245.25491.78.245.255510
12491.78.246.0/2391.78.246.1 to 91.78.247.25491.78.247.255510
12591.78.248.0/2391.78.248.1 to 91.78.249.25491.78.249.255510
12691.78.250.0/2391.78.250.1 to 91.78.251.25491.78.251.255510
12791.78.252.0/2391.78.252.1 to 91.78.253.25491.78.253.255510
12891.78.254.0/2391.78.254.1 to 91.78.255.25491.78.255.255510

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