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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.

Network94.185.0.0/16
Usable hosts65,534
Subnet mask255.255.0.0
Addresses65,536
Network address
94.185.0.0
Broadcast address
94.185.255.255
First usable
94.185.0.1
Last usable
94.185.255.254
Usable hosts
65,534 (65,536 less the network and broadcast addresses)
Subnet mask
255.255.0.0
Wildcard mask
0.0.255.255 (Cisco ACLs, OSPF)
Prefix length
/16
Type
Public public
Old class
A (default /8)
As numbers
Hex 5EB90000 · Integer 1589182464 to 1589247999
Reverse DNS zone
185.94.in-addr.arpa
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address01011110.10111001..00000000.0000000094.185.0.0
Subnet mask11111111.11111111..00000000.00000000255.255.0.0
Network01011110.10111001..00000000.0000000094.185.0.0
Broadcast01011110.10111001..11111111.1111111194.185.255.255
Split into smaller subnets/23
/17 (2)/18 (4)/19 (8)/20 (16)/21 (32)/22 (64)/23 (128)/24 (256)/25 (512)/26 (1,024)/27 (2,048)/28 (4,096)

94.185.0.0/16 makes 128 subnets of /23.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
194.185.0.0/2394.185.0.1 to 94.185.1.25494.185.1.255510
294.185.2.0/2394.185.2.1 to 94.185.3.25494.185.3.255510
394.185.4.0/2394.185.4.1 to 94.185.5.25494.185.5.255510
494.185.6.0/2394.185.6.1 to 94.185.7.25494.185.7.255510
594.185.8.0/2394.185.8.1 to 94.185.9.25494.185.9.255510
694.185.10.0/2394.185.10.1 to 94.185.11.25494.185.11.255510
794.185.12.0/2394.185.12.1 to 94.185.13.25494.185.13.255510
894.185.14.0/2394.185.14.1 to 94.185.15.25494.185.15.255510
994.185.16.0/2394.185.16.1 to 94.185.17.25494.185.17.255510
1094.185.18.0/2394.185.18.1 to 94.185.19.25494.185.19.255510
1194.185.20.0/2394.185.20.1 to 94.185.21.25494.185.21.255510
1294.185.22.0/2394.185.22.1 to 94.185.23.25494.185.23.255510
1394.185.24.0/2394.185.24.1 to 94.185.25.25494.185.25.255510
1494.185.26.0/2394.185.26.1 to 94.185.27.25494.185.27.255510
1594.185.28.0/2394.185.28.1 to 94.185.29.25494.185.29.255510
1694.185.30.0/2394.185.30.1 to 94.185.31.25494.185.31.255510
1794.185.32.0/2394.185.32.1 to 94.185.33.25494.185.33.255510
1894.185.34.0/2394.185.34.1 to 94.185.35.25494.185.35.255510
1994.185.36.0/2394.185.36.1 to 94.185.37.25494.185.37.255510
2094.185.38.0/2394.185.38.1 to 94.185.39.25494.185.39.255510
2194.185.40.0/2394.185.40.1 to 94.185.41.25494.185.41.255510
2294.185.42.0/2394.185.42.1 to 94.185.43.25494.185.43.255510
2394.185.44.0/2394.185.44.1 to 94.185.45.25494.185.45.255510
2494.185.46.0/2394.185.46.1 to 94.185.47.25494.185.47.255510
2594.185.48.0/2394.185.48.1 to 94.185.49.25494.185.49.255510
2694.185.50.0/2394.185.50.1 to 94.185.51.25494.185.51.255510
2794.185.52.0/2394.185.52.1 to 94.185.53.25494.185.53.255510
2894.185.54.0/2394.185.54.1 to 94.185.55.25494.185.55.255510
2994.185.56.0/2394.185.56.1 to 94.185.57.25494.185.57.255510
3094.185.58.0/2394.185.58.1 to 94.185.59.25494.185.59.255510
3194.185.60.0/2394.185.60.1 to 94.185.61.25494.185.61.255510
3294.185.62.0/2394.185.62.1 to 94.185.63.25494.185.63.255510
3394.185.64.0/2394.185.64.1 to 94.185.65.25494.185.65.255510
3494.185.66.0/2394.185.66.1 to 94.185.67.25494.185.67.255510
3594.185.68.0/2394.185.68.1 to 94.185.69.25494.185.69.255510
3694.185.70.0/2394.185.70.1 to 94.185.71.25494.185.71.255510
3794.185.72.0/2394.185.72.1 to 94.185.73.25494.185.73.255510
3894.185.74.0/2394.185.74.1 to 94.185.75.25494.185.75.255510
3994.185.76.0/2394.185.76.1 to 94.185.77.25494.185.77.255510
4094.185.78.0/2394.185.78.1 to 94.185.79.25494.185.79.255510
4194.185.80.0/2394.185.80.1 to 94.185.81.25494.185.81.255510
4294.185.82.0/2394.185.82.1 to 94.185.83.25494.185.83.255510
4394.185.84.0/2394.185.84.1 to 94.185.85.25494.185.85.255510
4494.185.86.0/2394.185.86.1 to 94.185.87.25494.185.87.255510
4594.185.88.0/2394.185.88.1 to 94.185.89.25494.185.89.255510
4694.185.90.0/2394.185.90.1 to 94.185.91.25494.185.91.255510
4794.185.92.0/2394.185.92.1 to 94.185.93.25494.185.93.255510
4894.185.94.0/2394.185.94.1 to 94.185.95.25494.185.95.255510
4994.185.96.0/2394.185.96.1 to 94.185.97.25494.185.97.255510
5094.185.98.0/2394.185.98.1 to 94.185.99.25494.185.99.255510
5194.185.100.0/2394.185.100.1 to 94.185.101.25494.185.101.255510
5294.185.102.0/2394.185.102.1 to 94.185.103.25494.185.103.255510
5394.185.104.0/2394.185.104.1 to 94.185.105.25494.185.105.255510
5494.185.106.0/2394.185.106.1 to 94.185.107.25494.185.107.255510
5594.185.108.0/2394.185.108.1 to 94.185.109.25494.185.109.255510
5694.185.110.0/2394.185.110.1 to 94.185.111.25494.185.111.255510
5794.185.112.0/2394.185.112.1 to 94.185.113.25494.185.113.255510
5894.185.114.0/2394.185.114.1 to 94.185.115.25494.185.115.255510
5994.185.116.0/2394.185.116.1 to 94.185.117.25494.185.117.255510
6094.185.118.0/2394.185.118.1 to 94.185.119.25494.185.119.255510
6194.185.120.0/2394.185.120.1 to 94.185.121.25494.185.121.255510
6294.185.122.0/2394.185.122.1 to 94.185.123.25494.185.123.255510
6394.185.124.0/2394.185.124.1 to 94.185.125.25494.185.125.255510
6494.185.126.0/2394.185.126.1 to 94.185.127.25494.185.127.255510
6594.185.128.0/2394.185.128.1 to 94.185.129.25494.185.129.255510
6694.185.130.0/2394.185.130.1 to 94.185.131.25494.185.131.255510
6794.185.132.0/2394.185.132.1 to 94.185.133.25494.185.133.255510
6894.185.134.0/2394.185.134.1 to 94.185.135.25494.185.135.255510
6994.185.136.0/2394.185.136.1 to 94.185.137.25494.185.137.255510
7094.185.138.0/2394.185.138.1 to 94.185.139.25494.185.139.255510
7194.185.140.0/2394.185.140.1 to 94.185.141.25494.185.141.255510
7294.185.142.0/2394.185.142.1 to 94.185.143.25494.185.143.255510
7394.185.144.0/2394.185.144.1 to 94.185.145.25494.185.145.255510
7494.185.146.0/2394.185.146.1 to 94.185.147.25494.185.147.255510
7594.185.148.0/2394.185.148.1 to 94.185.149.25494.185.149.255510
7694.185.150.0/2394.185.150.1 to 94.185.151.25494.185.151.255510
7794.185.152.0/2394.185.152.1 to 94.185.153.25494.185.153.255510
7894.185.154.0/2394.185.154.1 to 94.185.155.25494.185.155.255510
7994.185.156.0/2394.185.156.1 to 94.185.157.25494.185.157.255510
8094.185.158.0/2394.185.158.1 to 94.185.159.25494.185.159.255510
8194.185.160.0/2394.185.160.1 to 94.185.161.25494.185.161.255510
8294.185.162.0/2394.185.162.1 to 94.185.163.25494.185.163.255510
8394.185.164.0/2394.185.164.1 to 94.185.165.25494.185.165.255510
8494.185.166.0/2394.185.166.1 to 94.185.167.25494.185.167.255510
8594.185.168.0/2394.185.168.1 to 94.185.169.25494.185.169.255510
8694.185.170.0/2394.185.170.1 to 94.185.171.25494.185.171.255510
8794.185.172.0/2394.185.172.1 to 94.185.173.25494.185.173.255510
8894.185.174.0/2394.185.174.1 to 94.185.175.25494.185.175.255510
8994.185.176.0/2394.185.176.1 to 94.185.177.25494.185.177.255510
9094.185.178.0/2394.185.178.1 to 94.185.179.25494.185.179.255510
9194.185.180.0/2394.185.180.1 to 94.185.181.25494.185.181.255510
9294.185.182.0/2394.185.182.1 to 94.185.183.25494.185.183.255510
9394.185.184.0/2394.185.184.1 to 94.185.185.25494.185.185.255510
9494.185.186.0/2394.185.186.1 to 94.185.187.25494.185.187.255510
9594.185.188.0/2394.185.188.1 to 94.185.189.25494.185.189.255510
9694.185.190.0/2394.185.190.1 to 94.185.191.25494.185.191.255510
9794.185.192.0/2394.185.192.1 to 94.185.193.25494.185.193.255510
9894.185.194.0/2394.185.194.1 to 94.185.195.25494.185.195.255510
9994.185.196.0/2394.185.196.1 to 94.185.197.25494.185.197.255510
10094.185.198.0/2394.185.198.1 to 94.185.199.25494.185.199.255510
10194.185.200.0/2394.185.200.1 to 94.185.201.25494.185.201.255510
10294.185.202.0/2394.185.202.1 to 94.185.203.25494.185.203.255510
10394.185.204.0/2394.185.204.1 to 94.185.205.25494.185.205.255510
10494.185.206.0/2394.185.206.1 to 94.185.207.25494.185.207.255510
10594.185.208.0/2394.185.208.1 to 94.185.209.25494.185.209.255510
10694.185.210.0/2394.185.210.1 to 94.185.211.25494.185.211.255510
10794.185.212.0/2394.185.212.1 to 94.185.213.25494.185.213.255510
10894.185.214.0/2394.185.214.1 to 94.185.215.25494.185.215.255510
10994.185.216.0/2394.185.216.1 to 94.185.217.25494.185.217.255510
11094.185.218.0/2394.185.218.1 to 94.185.219.25494.185.219.255510
11194.185.220.0/2394.185.220.1 to 94.185.221.25494.185.221.255510
11294.185.222.0/2394.185.222.1 to 94.185.223.25494.185.223.255510
11394.185.224.0/2394.185.224.1 to 94.185.225.25494.185.225.255510
11494.185.226.0/2394.185.226.1 to 94.185.227.25494.185.227.255510
11594.185.228.0/2394.185.228.1 to 94.185.229.25494.185.229.255510
11694.185.230.0/2394.185.230.1 to 94.185.231.25494.185.231.255510
11794.185.232.0/2394.185.232.1 to 94.185.233.25494.185.233.255510
11894.185.234.0/2394.185.234.1 to 94.185.235.25494.185.235.255510
11994.185.236.0/2394.185.236.1 to 94.185.237.25494.185.237.255510
12094.185.238.0/2394.185.238.1 to 94.185.239.25494.185.239.255510
12194.185.240.0/2394.185.240.1 to 94.185.241.25494.185.241.255510
12294.185.242.0/2394.185.242.1 to 94.185.243.25494.185.243.255510
12394.185.244.0/2394.185.244.1 to 94.185.245.25494.185.245.255510
12494.185.246.0/2394.185.246.1 to 94.185.247.25494.185.247.255510
12594.185.248.0/2394.185.248.1 to 94.185.249.25494.185.249.255510
12694.185.250.0/2394.185.250.1 to 94.185.251.25494.185.251.255510
12794.185.252.0/2394.185.252.1 to 94.185.253.25494.185.253.255510
12894.185.254.0/2394.185.254.1 to 94.185.255.25494.185.255.255510

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.