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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.

Network226.167.0.0/16
Usable hosts65,534
Subnet mask255.255.0.0
Addresses65,536
Network address
226.167.0.0
Broadcast address
226.167.255.255
First usable
226.167.0.1
Last usable
226.167.255.254
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
Multicast 224.0.0.0/4
One-to-many traffic, such as IPTV and routing protocols
Old class
D (multicast)
As numbers
Hex E2A70000 · Integer 3802595328 to 3802660863
Reverse DNS zone
167.226.in-addr.arpa
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address11100010.10100111..00000000.00000000226.167.0.0
Subnet mask11111111.11111111..00000000.00000000255.255.0.0
Network11100010.10100111..00000000.00000000226.167.0.0
Broadcast11100010.10100111..11111111.11111111226.167.255.255
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)

226.167.0.0/16 makes 128 subnets of /23.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1226.167.0.0/23226.167.0.1 to 226.167.1.254226.167.1.255510
2226.167.2.0/23226.167.2.1 to 226.167.3.254226.167.3.255510
3226.167.4.0/23226.167.4.1 to 226.167.5.254226.167.5.255510
4226.167.6.0/23226.167.6.1 to 226.167.7.254226.167.7.255510
5226.167.8.0/23226.167.8.1 to 226.167.9.254226.167.9.255510
6226.167.10.0/23226.167.10.1 to 226.167.11.254226.167.11.255510
7226.167.12.0/23226.167.12.1 to 226.167.13.254226.167.13.255510
8226.167.14.0/23226.167.14.1 to 226.167.15.254226.167.15.255510
9226.167.16.0/23226.167.16.1 to 226.167.17.254226.167.17.255510
10226.167.18.0/23226.167.18.1 to 226.167.19.254226.167.19.255510
11226.167.20.0/23226.167.20.1 to 226.167.21.254226.167.21.255510
12226.167.22.0/23226.167.22.1 to 226.167.23.254226.167.23.255510
13226.167.24.0/23226.167.24.1 to 226.167.25.254226.167.25.255510
14226.167.26.0/23226.167.26.1 to 226.167.27.254226.167.27.255510
15226.167.28.0/23226.167.28.1 to 226.167.29.254226.167.29.255510
16226.167.30.0/23226.167.30.1 to 226.167.31.254226.167.31.255510
17226.167.32.0/23226.167.32.1 to 226.167.33.254226.167.33.255510
18226.167.34.0/23226.167.34.1 to 226.167.35.254226.167.35.255510
19226.167.36.0/23226.167.36.1 to 226.167.37.254226.167.37.255510
20226.167.38.0/23226.167.38.1 to 226.167.39.254226.167.39.255510
21226.167.40.0/23226.167.40.1 to 226.167.41.254226.167.41.255510
22226.167.42.0/23226.167.42.1 to 226.167.43.254226.167.43.255510
23226.167.44.0/23226.167.44.1 to 226.167.45.254226.167.45.255510
24226.167.46.0/23226.167.46.1 to 226.167.47.254226.167.47.255510
25226.167.48.0/23226.167.48.1 to 226.167.49.254226.167.49.255510
26226.167.50.0/23226.167.50.1 to 226.167.51.254226.167.51.255510
27226.167.52.0/23226.167.52.1 to 226.167.53.254226.167.53.255510
28226.167.54.0/23226.167.54.1 to 226.167.55.254226.167.55.255510
29226.167.56.0/23226.167.56.1 to 226.167.57.254226.167.57.255510
30226.167.58.0/23226.167.58.1 to 226.167.59.254226.167.59.255510
31226.167.60.0/23226.167.60.1 to 226.167.61.254226.167.61.255510
32226.167.62.0/23226.167.62.1 to 226.167.63.254226.167.63.255510
33226.167.64.0/23226.167.64.1 to 226.167.65.254226.167.65.255510
34226.167.66.0/23226.167.66.1 to 226.167.67.254226.167.67.255510
35226.167.68.0/23226.167.68.1 to 226.167.69.254226.167.69.255510
36226.167.70.0/23226.167.70.1 to 226.167.71.254226.167.71.255510
37226.167.72.0/23226.167.72.1 to 226.167.73.254226.167.73.255510
38226.167.74.0/23226.167.74.1 to 226.167.75.254226.167.75.255510
39226.167.76.0/23226.167.76.1 to 226.167.77.254226.167.77.255510
40226.167.78.0/23226.167.78.1 to 226.167.79.254226.167.79.255510
41226.167.80.0/23226.167.80.1 to 226.167.81.254226.167.81.255510
42226.167.82.0/23226.167.82.1 to 226.167.83.254226.167.83.255510
43226.167.84.0/23226.167.84.1 to 226.167.85.254226.167.85.255510
44226.167.86.0/23226.167.86.1 to 226.167.87.254226.167.87.255510
45226.167.88.0/23226.167.88.1 to 226.167.89.254226.167.89.255510
46226.167.90.0/23226.167.90.1 to 226.167.91.254226.167.91.255510
47226.167.92.0/23226.167.92.1 to 226.167.93.254226.167.93.255510
48226.167.94.0/23226.167.94.1 to 226.167.95.254226.167.95.255510
49226.167.96.0/23226.167.96.1 to 226.167.97.254226.167.97.255510
50226.167.98.0/23226.167.98.1 to 226.167.99.254226.167.99.255510
51226.167.100.0/23226.167.100.1 to 226.167.101.254226.167.101.255510
52226.167.102.0/23226.167.102.1 to 226.167.103.254226.167.103.255510
53226.167.104.0/23226.167.104.1 to 226.167.105.254226.167.105.255510
54226.167.106.0/23226.167.106.1 to 226.167.107.254226.167.107.255510
55226.167.108.0/23226.167.108.1 to 226.167.109.254226.167.109.255510
56226.167.110.0/23226.167.110.1 to 226.167.111.254226.167.111.255510
57226.167.112.0/23226.167.112.1 to 226.167.113.254226.167.113.255510
58226.167.114.0/23226.167.114.1 to 226.167.115.254226.167.115.255510
59226.167.116.0/23226.167.116.1 to 226.167.117.254226.167.117.255510
60226.167.118.0/23226.167.118.1 to 226.167.119.254226.167.119.255510
61226.167.120.0/23226.167.120.1 to 226.167.121.254226.167.121.255510
62226.167.122.0/23226.167.122.1 to 226.167.123.254226.167.123.255510
63226.167.124.0/23226.167.124.1 to 226.167.125.254226.167.125.255510
64226.167.126.0/23226.167.126.1 to 226.167.127.254226.167.127.255510
65226.167.128.0/23226.167.128.1 to 226.167.129.254226.167.129.255510
66226.167.130.0/23226.167.130.1 to 226.167.131.254226.167.131.255510
67226.167.132.0/23226.167.132.1 to 226.167.133.254226.167.133.255510
68226.167.134.0/23226.167.134.1 to 226.167.135.254226.167.135.255510
69226.167.136.0/23226.167.136.1 to 226.167.137.254226.167.137.255510
70226.167.138.0/23226.167.138.1 to 226.167.139.254226.167.139.255510
71226.167.140.0/23226.167.140.1 to 226.167.141.254226.167.141.255510
72226.167.142.0/23226.167.142.1 to 226.167.143.254226.167.143.255510
73226.167.144.0/23226.167.144.1 to 226.167.145.254226.167.145.255510
74226.167.146.0/23226.167.146.1 to 226.167.147.254226.167.147.255510
75226.167.148.0/23226.167.148.1 to 226.167.149.254226.167.149.255510
76226.167.150.0/23226.167.150.1 to 226.167.151.254226.167.151.255510
77226.167.152.0/23226.167.152.1 to 226.167.153.254226.167.153.255510
78226.167.154.0/23226.167.154.1 to 226.167.155.254226.167.155.255510
79226.167.156.0/23226.167.156.1 to 226.167.157.254226.167.157.255510
80226.167.158.0/23226.167.158.1 to 226.167.159.254226.167.159.255510
81226.167.160.0/23226.167.160.1 to 226.167.161.254226.167.161.255510
82226.167.162.0/23226.167.162.1 to 226.167.163.254226.167.163.255510
83226.167.164.0/23226.167.164.1 to 226.167.165.254226.167.165.255510
84226.167.166.0/23226.167.166.1 to 226.167.167.254226.167.167.255510
85226.167.168.0/23226.167.168.1 to 226.167.169.254226.167.169.255510
86226.167.170.0/23226.167.170.1 to 226.167.171.254226.167.171.255510
87226.167.172.0/23226.167.172.1 to 226.167.173.254226.167.173.255510
88226.167.174.0/23226.167.174.1 to 226.167.175.254226.167.175.255510
89226.167.176.0/23226.167.176.1 to 226.167.177.254226.167.177.255510
90226.167.178.0/23226.167.178.1 to 226.167.179.254226.167.179.255510
91226.167.180.0/23226.167.180.1 to 226.167.181.254226.167.181.255510
92226.167.182.0/23226.167.182.1 to 226.167.183.254226.167.183.255510
93226.167.184.0/23226.167.184.1 to 226.167.185.254226.167.185.255510
94226.167.186.0/23226.167.186.1 to 226.167.187.254226.167.187.255510
95226.167.188.0/23226.167.188.1 to 226.167.189.254226.167.189.255510
96226.167.190.0/23226.167.190.1 to 226.167.191.254226.167.191.255510
97226.167.192.0/23226.167.192.1 to 226.167.193.254226.167.193.255510
98226.167.194.0/23226.167.194.1 to 226.167.195.254226.167.195.255510
99226.167.196.0/23226.167.196.1 to 226.167.197.254226.167.197.255510
100226.167.198.0/23226.167.198.1 to 226.167.199.254226.167.199.255510
101226.167.200.0/23226.167.200.1 to 226.167.201.254226.167.201.255510
102226.167.202.0/23226.167.202.1 to 226.167.203.254226.167.203.255510
103226.167.204.0/23226.167.204.1 to 226.167.205.254226.167.205.255510
104226.167.206.0/23226.167.206.1 to 226.167.207.254226.167.207.255510
105226.167.208.0/23226.167.208.1 to 226.167.209.254226.167.209.255510
106226.167.210.0/23226.167.210.1 to 226.167.211.254226.167.211.255510
107226.167.212.0/23226.167.212.1 to 226.167.213.254226.167.213.255510
108226.167.214.0/23226.167.214.1 to 226.167.215.254226.167.215.255510
109226.167.216.0/23226.167.216.1 to 226.167.217.254226.167.217.255510
110226.167.218.0/23226.167.218.1 to 226.167.219.254226.167.219.255510
111226.167.220.0/23226.167.220.1 to 226.167.221.254226.167.221.255510
112226.167.222.0/23226.167.222.1 to 226.167.223.254226.167.223.255510
113226.167.224.0/23226.167.224.1 to 226.167.225.254226.167.225.255510
114226.167.226.0/23226.167.226.1 to 226.167.227.254226.167.227.255510
115226.167.228.0/23226.167.228.1 to 226.167.229.254226.167.229.255510
116226.167.230.0/23226.167.230.1 to 226.167.231.254226.167.231.255510
117226.167.232.0/23226.167.232.1 to 226.167.233.254226.167.233.255510
118226.167.234.0/23226.167.234.1 to 226.167.235.254226.167.235.255510
119226.167.236.0/23226.167.236.1 to 226.167.237.254226.167.237.255510
120226.167.238.0/23226.167.238.1 to 226.167.239.254226.167.239.255510
121226.167.240.0/23226.167.240.1 to 226.167.241.254226.167.241.255510
122226.167.242.0/23226.167.242.1 to 226.167.243.254226.167.243.255510
123226.167.244.0/23226.167.244.1 to 226.167.245.254226.167.245.255510
124226.167.246.0/23226.167.246.1 to 226.167.247.254226.167.247.255510
125226.167.248.0/23226.167.248.1 to 226.167.249.254226.167.249.255510
126226.167.250.0/23226.167.250.1 to 226.167.251.254226.167.251.255510
127226.167.252.0/23226.167.252.1 to 226.167.253.254226.167.253.255510
128226.167.254.0/23226.167.254.1 to 226.167.255.254226.167.255.255510

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.