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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.

Network88.2.192.0/19
Usable hosts8,190
Subnet mask255.255.224.0
Addresses8,192
Network address
88.2.192.0
Broadcast address
88.2.223.255
First usable
88.2.192.1
Last usable
88.2.223.254
Usable hosts
8,190 (8,192 less the network and broadcast addresses)
Subnet mask
255.255.224.0
Wildcard mask
0.0.31.255 (Cisco ACLs, OSPF)
Prefix length
/19
Type
Public public
Old class
A (default /8)
As numbers
Hex 5802C000 · Integer 1476575232 to 1476583423
Reverse DNS zones
192.2.88.in-addr.arpa
193.2.88.in-addr.arpa
194.2.88.in-addr.arpa
195.2.88.in-addr.arpa
196.2.88.in-addr.arpa
197.2.88.in-addr.arpa
198.2.88.in-addr.arpa
199.2.88.in-addr.arpa
200.2.88.in-addr.arpa
201.2.88.in-addr.arpa
202.2.88.in-addr.arpa
203.2.88.in-addr.arpa
204.2.88.in-addr.arpa
205.2.88.in-addr.arpa
206.2.88.in-addr.arpa
207.2.88.in-addr.arpa
and 16 more
/19 is not on a 8-bit boundary, so it takes 32 /24 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address01011000.00000010.11000000.0000000088.2.192.0
Subnet mask11111111.11111111.11100000.00000000255.255.224.0
Network01011000.00000010.11000000.0000000088.2.192.0
Broadcast01011000.00000010.11011111.1111111188.2.223.255
Split into smaller subnets/26
/20 (2)/21 (4)/22 (8)/23 (16)/24 (32)/25 (64)/26 (128)/27 (256)/28 (512)/29 (1,024)/30 (2,048)/31 (4,096)

88.2.192.0/19 makes 128 subnets of /26.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
188.2.192.0/2688.2.192.1 to 88.2.192.6288.2.192.6362
288.2.192.64/2688.2.192.65 to 88.2.192.12688.2.192.12762
388.2.192.128/2688.2.192.129 to 88.2.192.19088.2.192.19162
488.2.192.192/2688.2.192.193 to 88.2.192.25488.2.192.25562
588.2.193.0/2688.2.193.1 to 88.2.193.6288.2.193.6362
688.2.193.64/2688.2.193.65 to 88.2.193.12688.2.193.12762
788.2.193.128/2688.2.193.129 to 88.2.193.19088.2.193.19162
888.2.193.192/2688.2.193.193 to 88.2.193.25488.2.193.25562
988.2.194.0/2688.2.194.1 to 88.2.194.6288.2.194.6362
1088.2.194.64/2688.2.194.65 to 88.2.194.12688.2.194.12762
1188.2.194.128/2688.2.194.129 to 88.2.194.19088.2.194.19162
1288.2.194.192/2688.2.194.193 to 88.2.194.25488.2.194.25562
1388.2.195.0/2688.2.195.1 to 88.2.195.6288.2.195.6362
1488.2.195.64/2688.2.195.65 to 88.2.195.12688.2.195.12762
1588.2.195.128/2688.2.195.129 to 88.2.195.19088.2.195.19162
1688.2.195.192/2688.2.195.193 to 88.2.195.25488.2.195.25562
1788.2.196.0/2688.2.196.1 to 88.2.196.6288.2.196.6362
1888.2.196.64/2688.2.196.65 to 88.2.196.12688.2.196.12762
1988.2.196.128/2688.2.196.129 to 88.2.196.19088.2.196.19162
2088.2.196.192/2688.2.196.193 to 88.2.196.25488.2.196.25562
2188.2.197.0/2688.2.197.1 to 88.2.197.6288.2.197.6362
2288.2.197.64/2688.2.197.65 to 88.2.197.12688.2.197.12762
2388.2.197.128/2688.2.197.129 to 88.2.197.19088.2.197.19162
2488.2.197.192/2688.2.197.193 to 88.2.197.25488.2.197.25562
2588.2.198.0/2688.2.198.1 to 88.2.198.6288.2.198.6362
2688.2.198.64/2688.2.198.65 to 88.2.198.12688.2.198.12762
2788.2.198.128/2688.2.198.129 to 88.2.198.19088.2.198.19162
2888.2.198.192/2688.2.198.193 to 88.2.198.25488.2.198.25562
2988.2.199.0/2688.2.199.1 to 88.2.199.6288.2.199.6362
3088.2.199.64/2688.2.199.65 to 88.2.199.12688.2.199.12762
3188.2.199.128/2688.2.199.129 to 88.2.199.19088.2.199.19162
3288.2.199.192/2688.2.199.193 to 88.2.199.25488.2.199.25562
3388.2.200.0/2688.2.200.1 to 88.2.200.6288.2.200.6362
3488.2.200.64/2688.2.200.65 to 88.2.200.12688.2.200.12762
3588.2.200.128/2688.2.200.129 to 88.2.200.19088.2.200.19162
3688.2.200.192/2688.2.200.193 to 88.2.200.25488.2.200.25562
3788.2.201.0/2688.2.201.1 to 88.2.201.6288.2.201.6362
3888.2.201.64/2688.2.201.65 to 88.2.201.12688.2.201.12762
3988.2.201.128/2688.2.201.129 to 88.2.201.19088.2.201.19162
4088.2.201.192/2688.2.201.193 to 88.2.201.25488.2.201.25562
4188.2.202.0/2688.2.202.1 to 88.2.202.6288.2.202.6362
4288.2.202.64/2688.2.202.65 to 88.2.202.12688.2.202.12762
4388.2.202.128/2688.2.202.129 to 88.2.202.19088.2.202.19162
4488.2.202.192/2688.2.202.193 to 88.2.202.25488.2.202.25562
4588.2.203.0/2688.2.203.1 to 88.2.203.6288.2.203.6362
4688.2.203.64/2688.2.203.65 to 88.2.203.12688.2.203.12762
4788.2.203.128/2688.2.203.129 to 88.2.203.19088.2.203.19162
4888.2.203.192/2688.2.203.193 to 88.2.203.25488.2.203.25562
4988.2.204.0/2688.2.204.1 to 88.2.204.6288.2.204.6362
5088.2.204.64/2688.2.204.65 to 88.2.204.12688.2.204.12762
5188.2.204.128/2688.2.204.129 to 88.2.204.19088.2.204.19162
5288.2.204.192/2688.2.204.193 to 88.2.204.25488.2.204.25562
5388.2.205.0/2688.2.205.1 to 88.2.205.6288.2.205.6362
5488.2.205.64/2688.2.205.65 to 88.2.205.12688.2.205.12762
5588.2.205.128/2688.2.205.129 to 88.2.205.19088.2.205.19162
5688.2.205.192/2688.2.205.193 to 88.2.205.25488.2.205.25562
5788.2.206.0/2688.2.206.1 to 88.2.206.6288.2.206.6362
5888.2.206.64/2688.2.206.65 to 88.2.206.12688.2.206.12762
5988.2.206.128/2688.2.206.129 to 88.2.206.19088.2.206.19162
6088.2.206.192/2688.2.206.193 to 88.2.206.25488.2.206.25562
6188.2.207.0/2688.2.207.1 to 88.2.207.6288.2.207.6362
6288.2.207.64/2688.2.207.65 to 88.2.207.12688.2.207.12762
6388.2.207.128/2688.2.207.129 to 88.2.207.19088.2.207.19162
6488.2.207.192/2688.2.207.193 to 88.2.207.25488.2.207.25562
6588.2.208.0/2688.2.208.1 to 88.2.208.6288.2.208.6362
6688.2.208.64/2688.2.208.65 to 88.2.208.12688.2.208.12762
6788.2.208.128/2688.2.208.129 to 88.2.208.19088.2.208.19162
6888.2.208.192/2688.2.208.193 to 88.2.208.25488.2.208.25562
6988.2.209.0/2688.2.209.1 to 88.2.209.6288.2.209.6362
7088.2.209.64/2688.2.209.65 to 88.2.209.12688.2.209.12762
7188.2.209.128/2688.2.209.129 to 88.2.209.19088.2.209.19162
7288.2.209.192/2688.2.209.193 to 88.2.209.25488.2.209.25562
7388.2.210.0/2688.2.210.1 to 88.2.210.6288.2.210.6362
7488.2.210.64/2688.2.210.65 to 88.2.210.12688.2.210.12762
7588.2.210.128/2688.2.210.129 to 88.2.210.19088.2.210.19162
7688.2.210.192/2688.2.210.193 to 88.2.210.25488.2.210.25562
7788.2.211.0/2688.2.211.1 to 88.2.211.6288.2.211.6362
7888.2.211.64/2688.2.211.65 to 88.2.211.12688.2.211.12762
7988.2.211.128/2688.2.211.129 to 88.2.211.19088.2.211.19162
8088.2.211.192/2688.2.211.193 to 88.2.211.25488.2.211.25562
8188.2.212.0/2688.2.212.1 to 88.2.212.6288.2.212.6362
8288.2.212.64/2688.2.212.65 to 88.2.212.12688.2.212.12762
8388.2.212.128/2688.2.212.129 to 88.2.212.19088.2.212.19162
8488.2.212.192/2688.2.212.193 to 88.2.212.25488.2.212.25562
8588.2.213.0/2688.2.213.1 to 88.2.213.6288.2.213.6362
8688.2.213.64/2688.2.213.65 to 88.2.213.12688.2.213.12762
8788.2.213.128/2688.2.213.129 to 88.2.213.19088.2.213.19162
8888.2.213.192/2688.2.213.193 to 88.2.213.25488.2.213.25562
8988.2.214.0/2688.2.214.1 to 88.2.214.6288.2.214.6362
9088.2.214.64/2688.2.214.65 to 88.2.214.12688.2.214.12762
9188.2.214.128/2688.2.214.129 to 88.2.214.19088.2.214.19162
9288.2.214.192/2688.2.214.193 to 88.2.214.25488.2.214.25562
9388.2.215.0/2688.2.215.1 to 88.2.215.6288.2.215.6362
9488.2.215.64/2688.2.215.65 to 88.2.215.12688.2.215.12762
9588.2.215.128/2688.2.215.129 to 88.2.215.19088.2.215.19162
9688.2.215.192/2688.2.215.193 to 88.2.215.25488.2.215.25562
9788.2.216.0/2688.2.216.1 to 88.2.216.6288.2.216.6362
9888.2.216.64/2688.2.216.65 to 88.2.216.12688.2.216.12762
9988.2.216.128/2688.2.216.129 to 88.2.216.19088.2.216.19162
10088.2.216.192/2688.2.216.193 to 88.2.216.25488.2.216.25562
10188.2.217.0/2688.2.217.1 to 88.2.217.6288.2.217.6362
10288.2.217.64/2688.2.217.65 to 88.2.217.12688.2.217.12762
10388.2.217.128/2688.2.217.129 to 88.2.217.19088.2.217.19162
10488.2.217.192/2688.2.217.193 to 88.2.217.25488.2.217.25562
10588.2.218.0/2688.2.218.1 to 88.2.218.6288.2.218.6362
10688.2.218.64/2688.2.218.65 to 88.2.218.12688.2.218.12762
10788.2.218.128/2688.2.218.129 to 88.2.218.19088.2.218.19162
10888.2.218.192/2688.2.218.193 to 88.2.218.25488.2.218.25562
10988.2.219.0/2688.2.219.1 to 88.2.219.6288.2.219.6362
11088.2.219.64/2688.2.219.65 to 88.2.219.12688.2.219.12762
11188.2.219.128/2688.2.219.129 to 88.2.219.19088.2.219.19162
11288.2.219.192/2688.2.219.193 to 88.2.219.25488.2.219.25562
11388.2.220.0/2688.2.220.1 to 88.2.220.6288.2.220.6362
11488.2.220.64/2688.2.220.65 to 88.2.220.12688.2.220.12762
11588.2.220.128/2688.2.220.129 to 88.2.220.19088.2.220.19162
11688.2.220.192/2688.2.220.193 to 88.2.220.25488.2.220.25562
11788.2.221.0/2688.2.221.1 to 88.2.221.6288.2.221.6362
11888.2.221.64/2688.2.221.65 to 88.2.221.12688.2.221.12762
11988.2.221.128/2688.2.221.129 to 88.2.221.19088.2.221.19162
12088.2.221.192/2688.2.221.193 to 88.2.221.25488.2.221.25562
12188.2.222.0/2688.2.222.1 to 88.2.222.6288.2.222.6362
12288.2.222.64/2688.2.222.65 to 88.2.222.12688.2.222.12762
12388.2.222.128/2688.2.222.129 to 88.2.222.19088.2.222.19162
12488.2.222.192/2688.2.222.193 to 88.2.222.25488.2.222.25562
12588.2.223.0/2688.2.223.1 to 88.2.223.6288.2.223.6362
12688.2.223.64/2688.2.223.65 to 88.2.223.12688.2.223.12762
12788.2.223.128/2688.2.223.129 to 88.2.223.19088.2.223.19162
12888.2.223.192/2688.2.223.193 to 88.2.223.25488.2.223.25562

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.