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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.

Network54.232.0.0/13
Usable hosts524,286
Subnet mask255.248.0.0
Addresses524,288
Network address
54.232.0.0
Broadcast address
54.239.255.255
First usable
54.232.0.1
Last usable
54.239.255.254
Usable hosts
524,286 (524,288 less the network and broadcast addresses)
Subnet mask
255.248.0.0
Wildcard mask
0.7.255.255 (Cisco ACLs, OSPF)
Prefix length
/13
Type
Public public
Old class
A (default /8)
As numbers
Hex 36E80000 · Integer 921174016 to 921698303
Reverse DNS zones
232.54.in-addr.arpa
233.54.in-addr.arpa
234.54.in-addr.arpa
235.54.in-addr.arpa
236.54.in-addr.arpa
237.54.in-addr.arpa
238.54.in-addr.arpa
239.54.in-addr.arpa
/13 is not on a 8-bit boundary, so it takes 8 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address00110110.11101000.00000000.0000000054.232.0.0
Subnet mask11111111.11111000.00000000.00000000255.248.0.0
Network00110110.11101000.00000000.0000000054.232.0.0
Broadcast00110110.11101111.11111111.1111111154.239.255.255
Split into smaller subnets/20
/14 (2)/15 (4)/16 (8)/17 (16)/18 (32)/19 (64)/20 (128)/21 (256)/22 (512)/23 (1,024)/24 (2,048)/25 (4,096)

54.232.0.0/13 makes 128 subnets of /20.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
154.232.0.0/2054.232.0.1 to 54.232.15.25454.232.15.2554,094
254.232.16.0/2054.232.16.1 to 54.232.31.25454.232.31.2554,094
354.232.32.0/2054.232.32.1 to 54.232.47.25454.232.47.2554,094
454.232.48.0/2054.232.48.1 to 54.232.63.25454.232.63.2554,094
554.232.64.0/2054.232.64.1 to 54.232.79.25454.232.79.2554,094
654.232.80.0/2054.232.80.1 to 54.232.95.25454.232.95.2554,094
754.232.96.0/2054.232.96.1 to 54.232.111.25454.232.111.2554,094
854.232.112.0/2054.232.112.1 to 54.232.127.25454.232.127.2554,094
954.232.128.0/2054.232.128.1 to 54.232.143.25454.232.143.2554,094
1054.232.144.0/2054.232.144.1 to 54.232.159.25454.232.159.2554,094
1154.232.160.0/2054.232.160.1 to 54.232.175.25454.232.175.2554,094
1254.232.176.0/2054.232.176.1 to 54.232.191.25454.232.191.2554,094
1354.232.192.0/2054.232.192.1 to 54.232.207.25454.232.207.2554,094
1454.232.208.0/2054.232.208.1 to 54.232.223.25454.232.223.2554,094
1554.232.224.0/2054.232.224.1 to 54.232.239.25454.232.239.2554,094
1654.232.240.0/2054.232.240.1 to 54.232.255.25454.232.255.2554,094
1754.233.0.0/2054.233.0.1 to 54.233.15.25454.233.15.2554,094
1854.233.16.0/2054.233.16.1 to 54.233.31.25454.233.31.2554,094
1954.233.32.0/2054.233.32.1 to 54.233.47.25454.233.47.2554,094
2054.233.48.0/2054.233.48.1 to 54.233.63.25454.233.63.2554,094
2154.233.64.0/2054.233.64.1 to 54.233.79.25454.233.79.2554,094
2254.233.80.0/2054.233.80.1 to 54.233.95.25454.233.95.2554,094
2354.233.96.0/2054.233.96.1 to 54.233.111.25454.233.111.2554,094
2454.233.112.0/2054.233.112.1 to 54.233.127.25454.233.127.2554,094
2554.233.128.0/2054.233.128.1 to 54.233.143.25454.233.143.2554,094
2654.233.144.0/2054.233.144.1 to 54.233.159.25454.233.159.2554,094
2754.233.160.0/2054.233.160.1 to 54.233.175.25454.233.175.2554,094
2854.233.176.0/2054.233.176.1 to 54.233.191.25454.233.191.2554,094
2954.233.192.0/2054.233.192.1 to 54.233.207.25454.233.207.2554,094
3054.233.208.0/2054.233.208.1 to 54.233.223.25454.233.223.2554,094
3154.233.224.0/2054.233.224.1 to 54.233.239.25454.233.239.2554,094
3254.233.240.0/2054.233.240.1 to 54.233.255.25454.233.255.2554,094
3354.234.0.0/2054.234.0.1 to 54.234.15.25454.234.15.2554,094
3454.234.16.0/2054.234.16.1 to 54.234.31.25454.234.31.2554,094
3554.234.32.0/2054.234.32.1 to 54.234.47.25454.234.47.2554,094
3654.234.48.0/2054.234.48.1 to 54.234.63.25454.234.63.2554,094
3754.234.64.0/2054.234.64.1 to 54.234.79.25454.234.79.2554,094
3854.234.80.0/2054.234.80.1 to 54.234.95.25454.234.95.2554,094
3954.234.96.0/2054.234.96.1 to 54.234.111.25454.234.111.2554,094
4054.234.112.0/2054.234.112.1 to 54.234.127.25454.234.127.2554,094
4154.234.128.0/2054.234.128.1 to 54.234.143.25454.234.143.2554,094
4254.234.144.0/2054.234.144.1 to 54.234.159.25454.234.159.2554,094
4354.234.160.0/2054.234.160.1 to 54.234.175.25454.234.175.2554,094
4454.234.176.0/2054.234.176.1 to 54.234.191.25454.234.191.2554,094
4554.234.192.0/2054.234.192.1 to 54.234.207.25454.234.207.2554,094
4654.234.208.0/2054.234.208.1 to 54.234.223.25454.234.223.2554,094
4754.234.224.0/2054.234.224.1 to 54.234.239.25454.234.239.2554,094
4854.234.240.0/2054.234.240.1 to 54.234.255.25454.234.255.2554,094
4954.235.0.0/2054.235.0.1 to 54.235.15.25454.235.15.2554,094
5054.235.16.0/2054.235.16.1 to 54.235.31.25454.235.31.2554,094
5154.235.32.0/2054.235.32.1 to 54.235.47.25454.235.47.2554,094
5254.235.48.0/2054.235.48.1 to 54.235.63.25454.235.63.2554,094
5354.235.64.0/2054.235.64.1 to 54.235.79.25454.235.79.2554,094
5454.235.80.0/2054.235.80.1 to 54.235.95.25454.235.95.2554,094
5554.235.96.0/2054.235.96.1 to 54.235.111.25454.235.111.2554,094
5654.235.112.0/2054.235.112.1 to 54.235.127.25454.235.127.2554,094
5754.235.128.0/2054.235.128.1 to 54.235.143.25454.235.143.2554,094
5854.235.144.0/2054.235.144.1 to 54.235.159.25454.235.159.2554,094
5954.235.160.0/2054.235.160.1 to 54.235.175.25454.235.175.2554,094
6054.235.176.0/2054.235.176.1 to 54.235.191.25454.235.191.2554,094
6154.235.192.0/2054.235.192.1 to 54.235.207.25454.235.207.2554,094
6254.235.208.0/2054.235.208.1 to 54.235.223.25454.235.223.2554,094
6354.235.224.0/2054.235.224.1 to 54.235.239.25454.235.239.2554,094
6454.235.240.0/2054.235.240.1 to 54.235.255.25454.235.255.2554,094
6554.236.0.0/2054.236.0.1 to 54.236.15.25454.236.15.2554,094
6654.236.16.0/2054.236.16.1 to 54.236.31.25454.236.31.2554,094
6754.236.32.0/2054.236.32.1 to 54.236.47.25454.236.47.2554,094
6854.236.48.0/2054.236.48.1 to 54.236.63.25454.236.63.2554,094
6954.236.64.0/2054.236.64.1 to 54.236.79.25454.236.79.2554,094
7054.236.80.0/2054.236.80.1 to 54.236.95.25454.236.95.2554,094
7154.236.96.0/2054.236.96.1 to 54.236.111.25454.236.111.2554,094
7254.236.112.0/2054.236.112.1 to 54.236.127.25454.236.127.2554,094
7354.236.128.0/2054.236.128.1 to 54.236.143.25454.236.143.2554,094
7454.236.144.0/2054.236.144.1 to 54.236.159.25454.236.159.2554,094
7554.236.160.0/2054.236.160.1 to 54.236.175.25454.236.175.2554,094
7654.236.176.0/2054.236.176.1 to 54.236.191.25454.236.191.2554,094
7754.236.192.0/2054.236.192.1 to 54.236.207.25454.236.207.2554,094
7854.236.208.0/2054.236.208.1 to 54.236.223.25454.236.223.2554,094
7954.236.224.0/2054.236.224.1 to 54.236.239.25454.236.239.2554,094
8054.236.240.0/2054.236.240.1 to 54.236.255.25454.236.255.2554,094
8154.237.0.0/2054.237.0.1 to 54.237.15.25454.237.15.2554,094
8254.237.16.0/2054.237.16.1 to 54.237.31.25454.237.31.2554,094
8354.237.32.0/2054.237.32.1 to 54.237.47.25454.237.47.2554,094
8454.237.48.0/2054.237.48.1 to 54.237.63.25454.237.63.2554,094
8554.237.64.0/2054.237.64.1 to 54.237.79.25454.237.79.2554,094
8654.237.80.0/2054.237.80.1 to 54.237.95.25454.237.95.2554,094
8754.237.96.0/2054.237.96.1 to 54.237.111.25454.237.111.2554,094
8854.237.112.0/2054.237.112.1 to 54.237.127.25454.237.127.2554,094
8954.237.128.0/2054.237.128.1 to 54.237.143.25454.237.143.2554,094
9054.237.144.0/2054.237.144.1 to 54.237.159.25454.237.159.2554,094
9154.237.160.0/2054.237.160.1 to 54.237.175.25454.237.175.2554,094
9254.237.176.0/2054.237.176.1 to 54.237.191.25454.237.191.2554,094
9354.237.192.0/2054.237.192.1 to 54.237.207.25454.237.207.2554,094
9454.237.208.0/2054.237.208.1 to 54.237.223.25454.237.223.2554,094
9554.237.224.0/2054.237.224.1 to 54.237.239.25454.237.239.2554,094
9654.237.240.0/2054.237.240.1 to 54.237.255.25454.237.255.2554,094
9754.238.0.0/2054.238.0.1 to 54.238.15.25454.238.15.2554,094
9854.238.16.0/2054.238.16.1 to 54.238.31.25454.238.31.2554,094
9954.238.32.0/2054.238.32.1 to 54.238.47.25454.238.47.2554,094
10054.238.48.0/2054.238.48.1 to 54.238.63.25454.238.63.2554,094
10154.238.64.0/2054.238.64.1 to 54.238.79.25454.238.79.2554,094
10254.238.80.0/2054.238.80.1 to 54.238.95.25454.238.95.2554,094
10354.238.96.0/2054.238.96.1 to 54.238.111.25454.238.111.2554,094
10454.238.112.0/2054.238.112.1 to 54.238.127.25454.238.127.2554,094
10554.238.128.0/2054.238.128.1 to 54.238.143.25454.238.143.2554,094
10654.238.144.0/2054.238.144.1 to 54.238.159.25454.238.159.2554,094
10754.238.160.0/2054.238.160.1 to 54.238.175.25454.238.175.2554,094
10854.238.176.0/2054.238.176.1 to 54.238.191.25454.238.191.2554,094
10954.238.192.0/2054.238.192.1 to 54.238.207.25454.238.207.2554,094
11054.238.208.0/2054.238.208.1 to 54.238.223.25454.238.223.2554,094
11154.238.224.0/2054.238.224.1 to 54.238.239.25454.238.239.2554,094
11254.238.240.0/2054.238.240.1 to 54.238.255.25454.238.255.2554,094
11354.239.0.0/2054.239.0.1 to 54.239.15.25454.239.15.2554,094
11454.239.16.0/2054.239.16.1 to 54.239.31.25454.239.31.2554,094
11554.239.32.0/2054.239.32.1 to 54.239.47.25454.239.47.2554,094
11654.239.48.0/2054.239.48.1 to 54.239.63.25454.239.63.2554,094
11754.239.64.0/2054.239.64.1 to 54.239.79.25454.239.79.2554,094
11854.239.80.0/2054.239.80.1 to 54.239.95.25454.239.95.2554,094
11954.239.96.0/2054.239.96.1 to 54.239.111.25454.239.111.2554,094
12054.239.112.0/2054.239.112.1 to 54.239.127.25454.239.127.2554,094
12154.239.128.0/2054.239.128.1 to 54.239.143.25454.239.143.2554,094
12254.239.144.0/2054.239.144.1 to 54.239.159.25454.239.159.2554,094
12354.239.160.0/2054.239.160.1 to 54.239.175.25454.239.175.2554,094
12454.239.176.0/2054.239.176.1 to 54.239.191.25454.239.191.2554,094
12554.239.192.0/2054.239.192.1 to 54.239.207.25454.239.207.2554,094
12654.239.208.0/2054.239.208.1 to 54.239.223.25454.239.223.2554,094
12754.239.224.0/2054.239.224.1 to 54.239.239.25454.239.239.2554,094
12854.239.240.0/2054.239.240.1 to 54.239.255.25454.239.255.2554,094

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.