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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.

Network84.0.0.0/9
Usable hosts8,388,606
Subnet mask255.128.0.0
Addresses8,388,608
Network address
84.0.0.0
Broadcast address
84.127.255.255
First usable
84.0.0.1
Last usable
84.127.255.254
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 54000000 · Integer 1409286144 to 1417674751
Reverse DNS zones
0.84.in-addr.arpa
1.84.in-addr.arpa
2.84.in-addr.arpa
3.84.in-addr.arpa
4.84.in-addr.arpa
5.84.in-addr.arpa
6.84.in-addr.arpa
7.84.in-addr.arpa
8.84.in-addr.arpa
9.84.in-addr.arpa
10.84.in-addr.arpa
11.84.in-addr.arpa
12.84.in-addr.arpa
13.84.in-addr.arpa
14.84.in-addr.arpa
15.84.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
Address01010100.00000000.00000000.0000000084.0.0.0
Subnet mask11111111.10000000.00000000.00000000255.128.0.0
Network01010100.00000000.00000000.0000000084.0.0.0
Broadcast01010100.01111111.11111111.1111111184.127.255.255
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)

84.0.0.0/9 makes 128 subnets of /16.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
184.0.0.0/1684.0.0.1 to 84.0.255.25484.0.255.25565,534
284.1.0.0/1684.1.0.1 to 84.1.255.25484.1.255.25565,534
384.2.0.0/1684.2.0.1 to 84.2.255.25484.2.255.25565,534
484.3.0.0/1684.3.0.1 to 84.3.255.25484.3.255.25565,534
584.4.0.0/1684.4.0.1 to 84.4.255.25484.4.255.25565,534
684.5.0.0/1684.5.0.1 to 84.5.255.25484.5.255.25565,534
784.6.0.0/1684.6.0.1 to 84.6.255.25484.6.255.25565,534
884.7.0.0/1684.7.0.1 to 84.7.255.25484.7.255.25565,534
984.8.0.0/1684.8.0.1 to 84.8.255.25484.8.255.25565,534
1084.9.0.0/1684.9.0.1 to 84.9.255.25484.9.255.25565,534
1184.10.0.0/1684.10.0.1 to 84.10.255.25484.10.255.25565,534
1284.11.0.0/1684.11.0.1 to 84.11.255.25484.11.255.25565,534
1384.12.0.0/1684.12.0.1 to 84.12.255.25484.12.255.25565,534
1484.13.0.0/1684.13.0.1 to 84.13.255.25484.13.255.25565,534
1584.14.0.0/1684.14.0.1 to 84.14.255.25484.14.255.25565,534
1684.15.0.0/1684.15.0.1 to 84.15.255.25484.15.255.25565,534
1784.16.0.0/1684.16.0.1 to 84.16.255.25484.16.255.25565,534
1884.17.0.0/1684.17.0.1 to 84.17.255.25484.17.255.25565,534
1984.18.0.0/1684.18.0.1 to 84.18.255.25484.18.255.25565,534
2084.19.0.0/1684.19.0.1 to 84.19.255.25484.19.255.25565,534
2184.20.0.0/1684.20.0.1 to 84.20.255.25484.20.255.25565,534
2284.21.0.0/1684.21.0.1 to 84.21.255.25484.21.255.25565,534
2384.22.0.0/1684.22.0.1 to 84.22.255.25484.22.255.25565,534
2484.23.0.0/1684.23.0.1 to 84.23.255.25484.23.255.25565,534
2584.24.0.0/1684.24.0.1 to 84.24.255.25484.24.255.25565,534
2684.25.0.0/1684.25.0.1 to 84.25.255.25484.25.255.25565,534
2784.26.0.0/1684.26.0.1 to 84.26.255.25484.26.255.25565,534
2884.27.0.0/1684.27.0.1 to 84.27.255.25484.27.255.25565,534
2984.28.0.0/1684.28.0.1 to 84.28.255.25484.28.255.25565,534
3084.29.0.0/1684.29.0.1 to 84.29.255.25484.29.255.25565,534
3184.30.0.0/1684.30.0.1 to 84.30.255.25484.30.255.25565,534
3284.31.0.0/1684.31.0.1 to 84.31.255.25484.31.255.25565,534
3384.32.0.0/1684.32.0.1 to 84.32.255.25484.32.255.25565,534
3484.33.0.0/1684.33.0.1 to 84.33.255.25484.33.255.25565,534
3584.34.0.0/1684.34.0.1 to 84.34.255.25484.34.255.25565,534
3684.35.0.0/1684.35.0.1 to 84.35.255.25484.35.255.25565,534
3784.36.0.0/1684.36.0.1 to 84.36.255.25484.36.255.25565,534
3884.37.0.0/1684.37.0.1 to 84.37.255.25484.37.255.25565,534
3984.38.0.0/1684.38.0.1 to 84.38.255.25484.38.255.25565,534
4084.39.0.0/1684.39.0.1 to 84.39.255.25484.39.255.25565,534
4184.40.0.0/1684.40.0.1 to 84.40.255.25484.40.255.25565,534
4284.41.0.0/1684.41.0.1 to 84.41.255.25484.41.255.25565,534
4384.42.0.0/1684.42.0.1 to 84.42.255.25484.42.255.25565,534
4484.43.0.0/1684.43.0.1 to 84.43.255.25484.43.255.25565,534
4584.44.0.0/1684.44.0.1 to 84.44.255.25484.44.255.25565,534
4684.45.0.0/1684.45.0.1 to 84.45.255.25484.45.255.25565,534
4784.46.0.0/1684.46.0.1 to 84.46.255.25484.46.255.25565,534
4884.47.0.0/1684.47.0.1 to 84.47.255.25484.47.255.25565,534
4984.48.0.0/1684.48.0.1 to 84.48.255.25484.48.255.25565,534
5084.49.0.0/1684.49.0.1 to 84.49.255.25484.49.255.25565,534
5184.50.0.0/1684.50.0.1 to 84.50.255.25484.50.255.25565,534
5284.51.0.0/1684.51.0.1 to 84.51.255.25484.51.255.25565,534
5384.52.0.0/1684.52.0.1 to 84.52.255.25484.52.255.25565,534
5484.53.0.0/1684.53.0.1 to 84.53.255.25484.53.255.25565,534
5584.54.0.0/1684.54.0.1 to 84.54.255.25484.54.255.25565,534
5684.55.0.0/1684.55.0.1 to 84.55.255.25484.55.255.25565,534
5784.56.0.0/1684.56.0.1 to 84.56.255.25484.56.255.25565,534
5884.57.0.0/1684.57.0.1 to 84.57.255.25484.57.255.25565,534
5984.58.0.0/1684.58.0.1 to 84.58.255.25484.58.255.25565,534
6084.59.0.0/1684.59.0.1 to 84.59.255.25484.59.255.25565,534
6184.60.0.0/1684.60.0.1 to 84.60.255.25484.60.255.25565,534
6284.61.0.0/1684.61.0.1 to 84.61.255.25484.61.255.25565,534
6384.62.0.0/1684.62.0.1 to 84.62.255.25484.62.255.25565,534
6484.63.0.0/1684.63.0.1 to 84.63.255.25484.63.255.25565,534
6584.64.0.0/1684.64.0.1 to 84.64.255.25484.64.255.25565,534
6684.65.0.0/1684.65.0.1 to 84.65.255.25484.65.255.25565,534
6784.66.0.0/1684.66.0.1 to 84.66.255.25484.66.255.25565,534
6884.67.0.0/1684.67.0.1 to 84.67.255.25484.67.255.25565,534
6984.68.0.0/1684.68.0.1 to 84.68.255.25484.68.255.25565,534
7084.69.0.0/1684.69.0.1 to 84.69.255.25484.69.255.25565,534
7184.70.0.0/1684.70.0.1 to 84.70.255.25484.70.255.25565,534
7284.71.0.0/1684.71.0.1 to 84.71.255.25484.71.255.25565,534
7384.72.0.0/1684.72.0.1 to 84.72.255.25484.72.255.25565,534
7484.73.0.0/1684.73.0.1 to 84.73.255.25484.73.255.25565,534
7584.74.0.0/1684.74.0.1 to 84.74.255.25484.74.255.25565,534
7684.75.0.0/1684.75.0.1 to 84.75.255.25484.75.255.25565,534
7784.76.0.0/1684.76.0.1 to 84.76.255.25484.76.255.25565,534
7884.77.0.0/1684.77.0.1 to 84.77.255.25484.77.255.25565,534
7984.78.0.0/1684.78.0.1 to 84.78.255.25484.78.255.25565,534
8084.79.0.0/1684.79.0.1 to 84.79.255.25484.79.255.25565,534
8184.80.0.0/1684.80.0.1 to 84.80.255.25484.80.255.25565,534
8284.81.0.0/1684.81.0.1 to 84.81.255.25484.81.255.25565,534
8384.82.0.0/1684.82.0.1 to 84.82.255.25484.82.255.25565,534
8484.83.0.0/1684.83.0.1 to 84.83.255.25484.83.255.25565,534
8584.84.0.0/1684.84.0.1 to 84.84.255.25484.84.255.25565,534
8684.85.0.0/1684.85.0.1 to 84.85.255.25484.85.255.25565,534
8784.86.0.0/1684.86.0.1 to 84.86.255.25484.86.255.25565,534
8884.87.0.0/1684.87.0.1 to 84.87.255.25484.87.255.25565,534
8984.88.0.0/1684.88.0.1 to 84.88.255.25484.88.255.25565,534
9084.89.0.0/1684.89.0.1 to 84.89.255.25484.89.255.25565,534
9184.90.0.0/1684.90.0.1 to 84.90.255.25484.90.255.25565,534
9284.91.0.0/1684.91.0.1 to 84.91.255.25484.91.255.25565,534
9384.92.0.0/1684.92.0.1 to 84.92.255.25484.92.255.25565,534
9484.93.0.0/1684.93.0.1 to 84.93.255.25484.93.255.25565,534
9584.94.0.0/1684.94.0.1 to 84.94.255.25484.94.255.25565,534
9684.95.0.0/1684.95.0.1 to 84.95.255.25484.95.255.25565,534
9784.96.0.0/1684.96.0.1 to 84.96.255.25484.96.255.25565,534
9884.97.0.0/1684.97.0.1 to 84.97.255.25484.97.255.25565,534
9984.98.0.0/1684.98.0.1 to 84.98.255.25484.98.255.25565,534
10084.99.0.0/1684.99.0.1 to 84.99.255.25484.99.255.25565,534
10184.100.0.0/1684.100.0.1 to 84.100.255.25484.100.255.25565,534
10284.101.0.0/1684.101.0.1 to 84.101.255.25484.101.255.25565,534
10384.102.0.0/1684.102.0.1 to 84.102.255.25484.102.255.25565,534
10484.103.0.0/1684.103.0.1 to 84.103.255.25484.103.255.25565,534
10584.104.0.0/1684.104.0.1 to 84.104.255.25484.104.255.25565,534
10684.105.0.0/1684.105.0.1 to 84.105.255.25484.105.255.25565,534
10784.106.0.0/1684.106.0.1 to 84.106.255.25484.106.255.25565,534
10884.107.0.0/1684.107.0.1 to 84.107.255.25484.107.255.25565,534
10984.108.0.0/1684.108.0.1 to 84.108.255.25484.108.255.25565,534
11084.109.0.0/1684.109.0.1 to 84.109.255.25484.109.255.25565,534
11184.110.0.0/1684.110.0.1 to 84.110.255.25484.110.255.25565,534
11284.111.0.0/1684.111.0.1 to 84.111.255.25484.111.255.25565,534
11384.112.0.0/1684.112.0.1 to 84.112.255.25484.112.255.25565,534
11484.113.0.0/1684.113.0.1 to 84.113.255.25484.113.255.25565,534
11584.114.0.0/1684.114.0.1 to 84.114.255.25484.114.255.25565,534
11684.115.0.0/1684.115.0.1 to 84.115.255.25484.115.255.25565,534
11784.116.0.0/1684.116.0.1 to 84.116.255.25484.116.255.25565,534
11884.117.0.0/1684.117.0.1 to 84.117.255.25484.117.255.25565,534
11984.118.0.0/1684.118.0.1 to 84.118.255.25484.118.255.25565,534
12084.119.0.0/1684.119.0.1 to 84.119.255.25484.119.255.25565,534
12184.120.0.0/1684.120.0.1 to 84.120.255.25484.120.255.25565,534
12284.121.0.0/1684.121.0.1 to 84.121.255.25484.121.255.25565,534
12384.122.0.0/1684.122.0.1 to 84.122.255.25484.122.255.25565,534
12484.123.0.0/1684.123.0.1 to 84.123.255.25484.123.255.25565,534
12584.124.0.0/1684.124.0.1 to 84.124.255.25484.124.255.25565,534
12684.125.0.0/1684.125.0.1 to 84.125.255.25484.125.255.25565,534
12784.126.0.0/1684.126.0.1 to 84.126.255.25484.126.255.25565,534
12884.127.0.0/1684.127.0.1 to 84.127.255.25484.127.255.25565,534

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.