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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.

Network93.128.0.0/9
Usable hosts8,388,606
Subnet mask255.128.0.0
Addresses8,388,608
Network address
93.128.0.0
Broadcast address
93.255.255.255
First usable
93.128.0.1
Last usable
93.255.255.254
Usable hosts
8,388,606 (8,388,608 less the network and broadcast addresses)
Subnet mask
255.128.0.0
Wildcard mask
0.127.255.255 (Cisco ACLs, OSPF)
Prefix length
/9
Type
Public public
Old class
A (default /8)
As numbers
Hex 5D800000 · Integer 1568669696 to 1577058303
Reverse DNS zones
128.93.in-addr.arpa
129.93.in-addr.arpa
130.93.in-addr.arpa
131.93.in-addr.arpa
132.93.in-addr.arpa
133.93.in-addr.arpa
134.93.in-addr.arpa
135.93.in-addr.arpa
136.93.in-addr.arpa
137.93.in-addr.arpa
138.93.in-addr.arpa
139.93.in-addr.arpa
140.93.in-addr.arpa
141.93.in-addr.arpa
142.93.in-addr.arpa
143.93.in-addr.arpa
and 112 more
/9 is not on a 8-bit boundary, so it takes 128 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address01011101.10000000.00000000.0000000093.128.0.0
Subnet mask11111111.10000000.00000000.00000000255.128.0.0
Network01011101.10000000.00000000.0000000093.128.0.0
Broadcast01011101.11111111.11111111.1111111193.255.255.255
Split into smaller subnets/16
/10 (2)/11 (4)/12 (8)/13 (16)/14 (32)/15 (64)/16 (128)/17 (256)/18 (512)/19 (1,024)/20 (2,048)/21 (4,096)

93.128.0.0/9 makes 128 subnets of /16.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
193.128.0.0/1693.128.0.1 to 93.128.255.25493.128.255.25565,534
293.129.0.0/1693.129.0.1 to 93.129.255.25493.129.255.25565,534
393.130.0.0/1693.130.0.1 to 93.130.255.25493.130.255.25565,534
493.131.0.0/1693.131.0.1 to 93.131.255.25493.131.255.25565,534
593.132.0.0/1693.132.0.1 to 93.132.255.25493.132.255.25565,534
693.133.0.0/1693.133.0.1 to 93.133.255.25493.133.255.25565,534
793.134.0.0/1693.134.0.1 to 93.134.255.25493.134.255.25565,534
893.135.0.0/1693.135.0.1 to 93.135.255.25493.135.255.25565,534
993.136.0.0/1693.136.0.1 to 93.136.255.25493.136.255.25565,534
1093.137.0.0/1693.137.0.1 to 93.137.255.25493.137.255.25565,534
1193.138.0.0/1693.138.0.1 to 93.138.255.25493.138.255.25565,534
1293.139.0.0/1693.139.0.1 to 93.139.255.25493.139.255.25565,534
1393.140.0.0/1693.140.0.1 to 93.140.255.25493.140.255.25565,534
1493.141.0.0/1693.141.0.1 to 93.141.255.25493.141.255.25565,534
1593.142.0.0/1693.142.0.1 to 93.142.255.25493.142.255.25565,534
1693.143.0.0/1693.143.0.1 to 93.143.255.25493.143.255.25565,534
1793.144.0.0/1693.144.0.1 to 93.144.255.25493.144.255.25565,534
1893.145.0.0/1693.145.0.1 to 93.145.255.25493.145.255.25565,534
1993.146.0.0/1693.146.0.1 to 93.146.255.25493.146.255.25565,534
2093.147.0.0/1693.147.0.1 to 93.147.255.25493.147.255.25565,534
2193.148.0.0/1693.148.0.1 to 93.148.255.25493.148.255.25565,534
2293.149.0.0/1693.149.0.1 to 93.149.255.25493.149.255.25565,534
2393.150.0.0/1693.150.0.1 to 93.150.255.25493.150.255.25565,534
2493.151.0.0/1693.151.0.1 to 93.151.255.25493.151.255.25565,534
2593.152.0.0/1693.152.0.1 to 93.152.255.25493.152.255.25565,534
2693.153.0.0/1693.153.0.1 to 93.153.255.25493.153.255.25565,534
2793.154.0.0/1693.154.0.1 to 93.154.255.25493.154.255.25565,534
2893.155.0.0/1693.155.0.1 to 93.155.255.25493.155.255.25565,534
2993.156.0.0/1693.156.0.1 to 93.156.255.25493.156.255.25565,534
3093.157.0.0/1693.157.0.1 to 93.157.255.25493.157.255.25565,534
3193.158.0.0/1693.158.0.1 to 93.158.255.25493.158.255.25565,534
3293.159.0.0/1693.159.0.1 to 93.159.255.25493.159.255.25565,534
3393.160.0.0/1693.160.0.1 to 93.160.255.25493.160.255.25565,534
3493.161.0.0/1693.161.0.1 to 93.161.255.25493.161.255.25565,534
3593.162.0.0/1693.162.0.1 to 93.162.255.25493.162.255.25565,534
3693.163.0.0/1693.163.0.1 to 93.163.255.25493.163.255.25565,534
3793.164.0.0/1693.164.0.1 to 93.164.255.25493.164.255.25565,534
3893.165.0.0/1693.165.0.1 to 93.165.255.25493.165.255.25565,534
3993.166.0.0/1693.166.0.1 to 93.166.255.25493.166.255.25565,534
4093.167.0.0/1693.167.0.1 to 93.167.255.25493.167.255.25565,534
4193.168.0.0/1693.168.0.1 to 93.168.255.25493.168.255.25565,534
4293.169.0.0/1693.169.0.1 to 93.169.255.25493.169.255.25565,534
4393.170.0.0/1693.170.0.1 to 93.170.255.25493.170.255.25565,534
4493.171.0.0/1693.171.0.1 to 93.171.255.25493.171.255.25565,534
4593.172.0.0/1693.172.0.1 to 93.172.255.25493.172.255.25565,534
4693.173.0.0/1693.173.0.1 to 93.173.255.25493.173.255.25565,534
4793.174.0.0/1693.174.0.1 to 93.174.255.25493.174.255.25565,534
4893.175.0.0/1693.175.0.1 to 93.175.255.25493.175.255.25565,534
4993.176.0.0/1693.176.0.1 to 93.176.255.25493.176.255.25565,534
5093.177.0.0/1693.177.0.1 to 93.177.255.25493.177.255.25565,534
5193.178.0.0/1693.178.0.1 to 93.178.255.25493.178.255.25565,534
5293.179.0.0/1693.179.0.1 to 93.179.255.25493.179.255.25565,534
5393.180.0.0/1693.180.0.1 to 93.180.255.25493.180.255.25565,534
5493.181.0.0/1693.181.0.1 to 93.181.255.25493.181.255.25565,534
5593.182.0.0/1693.182.0.1 to 93.182.255.25493.182.255.25565,534
5693.183.0.0/1693.183.0.1 to 93.183.255.25493.183.255.25565,534
5793.184.0.0/1693.184.0.1 to 93.184.255.25493.184.255.25565,534
5893.185.0.0/1693.185.0.1 to 93.185.255.25493.185.255.25565,534
5993.186.0.0/1693.186.0.1 to 93.186.255.25493.186.255.25565,534
6093.187.0.0/1693.187.0.1 to 93.187.255.25493.187.255.25565,534
6193.188.0.0/1693.188.0.1 to 93.188.255.25493.188.255.25565,534
6293.189.0.0/1693.189.0.1 to 93.189.255.25493.189.255.25565,534
6393.190.0.0/1693.190.0.1 to 93.190.255.25493.190.255.25565,534
6493.191.0.0/1693.191.0.1 to 93.191.255.25493.191.255.25565,534
6593.192.0.0/1693.192.0.1 to 93.192.255.25493.192.255.25565,534
6693.193.0.0/1693.193.0.1 to 93.193.255.25493.193.255.25565,534
6793.194.0.0/1693.194.0.1 to 93.194.255.25493.194.255.25565,534
6893.195.0.0/1693.195.0.1 to 93.195.255.25493.195.255.25565,534
6993.196.0.0/1693.196.0.1 to 93.196.255.25493.196.255.25565,534
7093.197.0.0/1693.197.0.1 to 93.197.255.25493.197.255.25565,534
7193.198.0.0/1693.198.0.1 to 93.198.255.25493.198.255.25565,534
7293.199.0.0/1693.199.0.1 to 93.199.255.25493.199.255.25565,534
7393.200.0.0/1693.200.0.1 to 93.200.255.25493.200.255.25565,534
7493.201.0.0/1693.201.0.1 to 93.201.255.25493.201.255.25565,534
7593.202.0.0/1693.202.0.1 to 93.202.255.25493.202.255.25565,534
7693.203.0.0/1693.203.0.1 to 93.203.255.25493.203.255.25565,534
7793.204.0.0/1693.204.0.1 to 93.204.255.25493.204.255.25565,534
7893.205.0.0/1693.205.0.1 to 93.205.255.25493.205.255.25565,534
7993.206.0.0/1693.206.0.1 to 93.206.255.25493.206.255.25565,534
8093.207.0.0/1693.207.0.1 to 93.207.255.25493.207.255.25565,534
8193.208.0.0/1693.208.0.1 to 93.208.255.25493.208.255.25565,534
8293.209.0.0/1693.209.0.1 to 93.209.255.25493.209.255.25565,534
8393.210.0.0/1693.210.0.1 to 93.210.255.25493.210.255.25565,534
8493.211.0.0/1693.211.0.1 to 93.211.255.25493.211.255.25565,534
8593.212.0.0/1693.212.0.1 to 93.212.255.25493.212.255.25565,534
8693.213.0.0/1693.213.0.1 to 93.213.255.25493.213.255.25565,534
8793.214.0.0/1693.214.0.1 to 93.214.255.25493.214.255.25565,534
8893.215.0.0/1693.215.0.1 to 93.215.255.25493.215.255.25565,534
8993.216.0.0/1693.216.0.1 to 93.216.255.25493.216.255.25565,534
9093.217.0.0/1693.217.0.1 to 93.217.255.25493.217.255.25565,534
9193.218.0.0/1693.218.0.1 to 93.218.255.25493.218.255.25565,534
9293.219.0.0/1693.219.0.1 to 93.219.255.25493.219.255.25565,534
9393.220.0.0/1693.220.0.1 to 93.220.255.25493.220.255.25565,534
9493.221.0.0/1693.221.0.1 to 93.221.255.25493.221.255.25565,534
9593.222.0.0/1693.222.0.1 to 93.222.255.25493.222.255.25565,534
9693.223.0.0/1693.223.0.1 to 93.223.255.25493.223.255.25565,534
9793.224.0.0/1693.224.0.1 to 93.224.255.25493.224.255.25565,534
9893.225.0.0/1693.225.0.1 to 93.225.255.25493.225.255.25565,534
9993.226.0.0/1693.226.0.1 to 93.226.255.25493.226.255.25565,534
10093.227.0.0/1693.227.0.1 to 93.227.255.25493.227.255.25565,534
10193.228.0.0/1693.228.0.1 to 93.228.255.25493.228.255.25565,534
10293.229.0.0/1693.229.0.1 to 93.229.255.25493.229.255.25565,534
10393.230.0.0/1693.230.0.1 to 93.230.255.25493.230.255.25565,534
10493.231.0.0/1693.231.0.1 to 93.231.255.25493.231.255.25565,534
10593.232.0.0/1693.232.0.1 to 93.232.255.25493.232.255.25565,534
10693.233.0.0/1693.233.0.1 to 93.233.255.25493.233.255.25565,534
10793.234.0.0/1693.234.0.1 to 93.234.255.25493.234.255.25565,534
10893.235.0.0/1693.235.0.1 to 93.235.255.25493.235.255.25565,534
10993.236.0.0/1693.236.0.1 to 93.236.255.25493.236.255.25565,534
11093.237.0.0/1693.237.0.1 to 93.237.255.25493.237.255.25565,534
11193.238.0.0/1693.238.0.1 to 93.238.255.25493.238.255.25565,534
11293.239.0.0/1693.239.0.1 to 93.239.255.25493.239.255.25565,534
11393.240.0.0/1693.240.0.1 to 93.240.255.25493.240.255.25565,534
11493.241.0.0/1693.241.0.1 to 93.241.255.25493.241.255.25565,534
11593.242.0.0/1693.242.0.1 to 93.242.255.25493.242.255.25565,534
11693.243.0.0/1693.243.0.1 to 93.243.255.25493.243.255.25565,534
11793.244.0.0/1693.244.0.1 to 93.244.255.25493.244.255.25565,534
11893.245.0.0/1693.245.0.1 to 93.245.255.25493.245.255.25565,534
11993.246.0.0/1693.246.0.1 to 93.246.255.25493.246.255.25565,534
12093.247.0.0/1693.247.0.1 to 93.247.255.25493.247.255.25565,534
12193.248.0.0/1693.248.0.1 to 93.248.255.25493.248.255.25565,534
12293.249.0.0/1693.249.0.1 to 93.249.255.25493.249.255.25565,534
12393.250.0.0/1693.250.0.1 to 93.250.255.25493.250.255.25565,534
12493.251.0.0/1693.251.0.1 to 93.251.255.25493.251.255.25565,534
12593.252.0.0/1693.252.0.1 to 93.252.255.25493.252.255.25565,534
12693.253.0.0/1693.253.0.1 to 93.253.255.25493.253.255.25565,534
12793.254.0.0/1693.254.0.1 to 93.254.255.25493.254.255.25565,534
12893.255.0.0/1693.255.0.1 to 93.255.255.25493.255.255.25565,534

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.