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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.

Network84.182.0.0/15
Usable hosts131,070
Subnet mask255.254.0.0
Addresses131,072
Network address
84.182.0.0
Broadcast address
84.183.255.255
First usable
84.182.0.1
Last usable
84.183.255.254
Usable hosts
131,070 (131,072 less the network and broadcast addresses)
Subnet mask
255.254.0.0
Wildcard mask
0.1.255.255 (Cisco ACLs, OSPF)
Prefix length
/15
Type
Public public
Old class
A (default /8)
As numbers
Hex 54B60000 · Integer 1421213696 to 1421344767
Reverse DNS zones
182.84.in-addr.arpa
183.84.in-addr.arpa
/15 is not on a 8-bit boundary, so it takes 2 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address01010100.10110110.00000000.0000000084.182.0.0
Subnet mask11111111.11111110.00000000.00000000255.254.0.0
Network01010100.10110110.00000000.0000000084.182.0.0
Broadcast01010100.10110111.11111111.1111111184.183.255.255
Split into smaller subnets/22
/16 (2)/17 (4)/18 (8)/19 (16)/20 (32)/21 (64)/22 (128)/23 (256)/24 (512)/25 (1,024)/26 (2,048)/27 (4,096)

84.182.0.0/15 makes 128 subnets of /22.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
184.182.0.0/2284.182.0.1 to 84.182.3.25484.182.3.2551,022
284.182.4.0/2284.182.4.1 to 84.182.7.25484.182.7.2551,022
384.182.8.0/2284.182.8.1 to 84.182.11.25484.182.11.2551,022
484.182.12.0/2284.182.12.1 to 84.182.15.25484.182.15.2551,022
584.182.16.0/2284.182.16.1 to 84.182.19.25484.182.19.2551,022
684.182.20.0/2284.182.20.1 to 84.182.23.25484.182.23.2551,022
784.182.24.0/2284.182.24.1 to 84.182.27.25484.182.27.2551,022
884.182.28.0/2284.182.28.1 to 84.182.31.25484.182.31.2551,022
984.182.32.0/2284.182.32.1 to 84.182.35.25484.182.35.2551,022
1084.182.36.0/2284.182.36.1 to 84.182.39.25484.182.39.2551,022
1184.182.40.0/2284.182.40.1 to 84.182.43.25484.182.43.2551,022
1284.182.44.0/2284.182.44.1 to 84.182.47.25484.182.47.2551,022
1384.182.48.0/2284.182.48.1 to 84.182.51.25484.182.51.2551,022
1484.182.52.0/2284.182.52.1 to 84.182.55.25484.182.55.2551,022
1584.182.56.0/2284.182.56.1 to 84.182.59.25484.182.59.2551,022
1684.182.60.0/2284.182.60.1 to 84.182.63.25484.182.63.2551,022
1784.182.64.0/2284.182.64.1 to 84.182.67.25484.182.67.2551,022
1884.182.68.0/2284.182.68.1 to 84.182.71.25484.182.71.2551,022
1984.182.72.0/2284.182.72.1 to 84.182.75.25484.182.75.2551,022
2084.182.76.0/2284.182.76.1 to 84.182.79.25484.182.79.2551,022
2184.182.80.0/2284.182.80.1 to 84.182.83.25484.182.83.2551,022
2284.182.84.0/2284.182.84.1 to 84.182.87.25484.182.87.2551,022
2384.182.88.0/2284.182.88.1 to 84.182.91.25484.182.91.2551,022
2484.182.92.0/2284.182.92.1 to 84.182.95.25484.182.95.2551,022
2584.182.96.0/2284.182.96.1 to 84.182.99.25484.182.99.2551,022
2684.182.100.0/2284.182.100.1 to 84.182.103.25484.182.103.2551,022
2784.182.104.0/2284.182.104.1 to 84.182.107.25484.182.107.2551,022
2884.182.108.0/2284.182.108.1 to 84.182.111.25484.182.111.2551,022
2984.182.112.0/2284.182.112.1 to 84.182.115.25484.182.115.2551,022
3084.182.116.0/2284.182.116.1 to 84.182.119.25484.182.119.2551,022
3184.182.120.0/2284.182.120.1 to 84.182.123.25484.182.123.2551,022
3284.182.124.0/2284.182.124.1 to 84.182.127.25484.182.127.2551,022
3384.182.128.0/2284.182.128.1 to 84.182.131.25484.182.131.2551,022
3484.182.132.0/2284.182.132.1 to 84.182.135.25484.182.135.2551,022
3584.182.136.0/2284.182.136.1 to 84.182.139.25484.182.139.2551,022
3684.182.140.0/2284.182.140.1 to 84.182.143.25484.182.143.2551,022
3784.182.144.0/2284.182.144.1 to 84.182.147.25484.182.147.2551,022
3884.182.148.0/2284.182.148.1 to 84.182.151.25484.182.151.2551,022
3984.182.152.0/2284.182.152.1 to 84.182.155.25484.182.155.2551,022
4084.182.156.0/2284.182.156.1 to 84.182.159.25484.182.159.2551,022
4184.182.160.0/2284.182.160.1 to 84.182.163.25484.182.163.2551,022
4284.182.164.0/2284.182.164.1 to 84.182.167.25484.182.167.2551,022
4384.182.168.0/2284.182.168.1 to 84.182.171.25484.182.171.2551,022
4484.182.172.0/2284.182.172.1 to 84.182.175.25484.182.175.2551,022
4584.182.176.0/2284.182.176.1 to 84.182.179.25484.182.179.2551,022
4684.182.180.0/2284.182.180.1 to 84.182.183.25484.182.183.2551,022
4784.182.184.0/2284.182.184.1 to 84.182.187.25484.182.187.2551,022
4884.182.188.0/2284.182.188.1 to 84.182.191.25484.182.191.2551,022
4984.182.192.0/2284.182.192.1 to 84.182.195.25484.182.195.2551,022
5084.182.196.0/2284.182.196.1 to 84.182.199.25484.182.199.2551,022
5184.182.200.0/2284.182.200.1 to 84.182.203.25484.182.203.2551,022
5284.182.204.0/2284.182.204.1 to 84.182.207.25484.182.207.2551,022
5384.182.208.0/2284.182.208.1 to 84.182.211.25484.182.211.2551,022
5484.182.212.0/2284.182.212.1 to 84.182.215.25484.182.215.2551,022
5584.182.216.0/2284.182.216.1 to 84.182.219.25484.182.219.2551,022
5684.182.220.0/2284.182.220.1 to 84.182.223.25484.182.223.2551,022
5784.182.224.0/2284.182.224.1 to 84.182.227.25484.182.227.2551,022
5884.182.228.0/2284.182.228.1 to 84.182.231.25484.182.231.2551,022
5984.182.232.0/2284.182.232.1 to 84.182.235.25484.182.235.2551,022
6084.182.236.0/2284.182.236.1 to 84.182.239.25484.182.239.2551,022
6184.182.240.0/2284.182.240.1 to 84.182.243.25484.182.243.2551,022
6284.182.244.0/2284.182.244.1 to 84.182.247.25484.182.247.2551,022
6384.182.248.0/2284.182.248.1 to 84.182.251.25484.182.251.2551,022
6484.182.252.0/2284.182.252.1 to 84.182.255.25484.182.255.2551,022
6584.183.0.0/2284.183.0.1 to 84.183.3.25484.183.3.2551,022
6684.183.4.0/2284.183.4.1 to 84.183.7.25484.183.7.2551,022
6784.183.8.0/2284.183.8.1 to 84.183.11.25484.183.11.2551,022
6884.183.12.0/2284.183.12.1 to 84.183.15.25484.183.15.2551,022
6984.183.16.0/2284.183.16.1 to 84.183.19.25484.183.19.2551,022
7084.183.20.0/2284.183.20.1 to 84.183.23.25484.183.23.2551,022
7184.183.24.0/2284.183.24.1 to 84.183.27.25484.183.27.2551,022
7284.183.28.0/2284.183.28.1 to 84.183.31.25484.183.31.2551,022
7384.183.32.0/2284.183.32.1 to 84.183.35.25484.183.35.2551,022
7484.183.36.0/2284.183.36.1 to 84.183.39.25484.183.39.2551,022
7584.183.40.0/2284.183.40.1 to 84.183.43.25484.183.43.2551,022
7684.183.44.0/2284.183.44.1 to 84.183.47.25484.183.47.2551,022
7784.183.48.0/2284.183.48.1 to 84.183.51.25484.183.51.2551,022
7884.183.52.0/2284.183.52.1 to 84.183.55.25484.183.55.2551,022
7984.183.56.0/2284.183.56.1 to 84.183.59.25484.183.59.2551,022
8084.183.60.0/2284.183.60.1 to 84.183.63.25484.183.63.2551,022
8184.183.64.0/2284.183.64.1 to 84.183.67.25484.183.67.2551,022
8284.183.68.0/2284.183.68.1 to 84.183.71.25484.183.71.2551,022
8384.183.72.0/2284.183.72.1 to 84.183.75.25484.183.75.2551,022
8484.183.76.0/2284.183.76.1 to 84.183.79.25484.183.79.2551,022
8584.183.80.0/2284.183.80.1 to 84.183.83.25484.183.83.2551,022
8684.183.84.0/2284.183.84.1 to 84.183.87.25484.183.87.2551,022
8784.183.88.0/2284.183.88.1 to 84.183.91.25484.183.91.2551,022
8884.183.92.0/2284.183.92.1 to 84.183.95.25484.183.95.2551,022
8984.183.96.0/2284.183.96.1 to 84.183.99.25484.183.99.2551,022
9084.183.100.0/2284.183.100.1 to 84.183.103.25484.183.103.2551,022
9184.183.104.0/2284.183.104.1 to 84.183.107.25484.183.107.2551,022
9284.183.108.0/2284.183.108.1 to 84.183.111.25484.183.111.2551,022
9384.183.112.0/2284.183.112.1 to 84.183.115.25484.183.115.2551,022
9484.183.116.0/2284.183.116.1 to 84.183.119.25484.183.119.2551,022
9584.183.120.0/2284.183.120.1 to 84.183.123.25484.183.123.2551,022
9684.183.124.0/2284.183.124.1 to 84.183.127.25484.183.127.2551,022
9784.183.128.0/2284.183.128.1 to 84.183.131.25484.183.131.2551,022
9884.183.132.0/2284.183.132.1 to 84.183.135.25484.183.135.2551,022
9984.183.136.0/2284.183.136.1 to 84.183.139.25484.183.139.2551,022
10084.183.140.0/2284.183.140.1 to 84.183.143.25484.183.143.2551,022
10184.183.144.0/2284.183.144.1 to 84.183.147.25484.183.147.2551,022
10284.183.148.0/2284.183.148.1 to 84.183.151.25484.183.151.2551,022
10384.183.152.0/2284.183.152.1 to 84.183.155.25484.183.155.2551,022
10484.183.156.0/2284.183.156.1 to 84.183.159.25484.183.159.2551,022
10584.183.160.0/2284.183.160.1 to 84.183.163.25484.183.163.2551,022
10684.183.164.0/2284.183.164.1 to 84.183.167.25484.183.167.2551,022
10784.183.168.0/2284.183.168.1 to 84.183.171.25484.183.171.2551,022
10884.183.172.0/2284.183.172.1 to 84.183.175.25484.183.175.2551,022
10984.183.176.0/2284.183.176.1 to 84.183.179.25484.183.179.2551,022
11084.183.180.0/2284.183.180.1 to 84.183.183.25484.183.183.2551,022
11184.183.184.0/2284.183.184.1 to 84.183.187.25484.183.187.2551,022
11284.183.188.0/2284.183.188.1 to 84.183.191.25484.183.191.2551,022
11384.183.192.0/2284.183.192.1 to 84.183.195.25484.183.195.2551,022
11484.183.196.0/2284.183.196.1 to 84.183.199.25484.183.199.2551,022
11584.183.200.0/2284.183.200.1 to 84.183.203.25484.183.203.2551,022
11684.183.204.0/2284.183.204.1 to 84.183.207.25484.183.207.2551,022
11784.183.208.0/2284.183.208.1 to 84.183.211.25484.183.211.2551,022
11884.183.212.0/2284.183.212.1 to 84.183.215.25484.183.215.2551,022
11984.183.216.0/2284.183.216.1 to 84.183.219.25484.183.219.2551,022
12084.183.220.0/2284.183.220.1 to 84.183.223.25484.183.223.2551,022
12184.183.224.0/2284.183.224.1 to 84.183.227.25484.183.227.2551,022
12284.183.228.0/2284.183.228.1 to 84.183.231.25484.183.231.2551,022
12384.183.232.0/2284.183.232.1 to 84.183.235.25484.183.235.2551,022
12484.183.236.0/2284.183.236.1 to 84.183.239.25484.183.239.2551,022
12584.183.240.0/2284.183.240.1 to 84.183.243.25484.183.243.2551,022
12684.183.244.0/2284.183.244.1 to 84.183.247.25484.183.247.2551,022
12784.183.248.0/2284.183.248.1 to 84.183.251.25484.183.251.2551,022
12884.183.252.0/2284.183.252.1 to 84.183.255.25484.183.255.2551,022

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.