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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.

Network116.0.0.0/6
Usable hosts67,108,862
Subnet mask252.0.0.0
Addresses67,108,864
Network address
116.0.0.0
Broadcast address
119.255.255.255
First usable
116.0.0.1
Last usable
119.255.255.254
Usable hosts
67,108,862 (67,108,864 less the network and broadcast addresses)
Subnet mask
252.0.0.0
Wildcard mask
3.255.255.255 (Cisco ACLs, OSPF)
Prefix length
/6
Type
Public public
Old class
A (default /8)
As numbers
Hex 74000000 · Integer 1946157056 to 2013265919
Reverse DNS zones
116.in-addr.arpa
117.in-addr.arpa
118.in-addr.arpa
119.in-addr.arpa
/6 is not on a 8-bit boundary, so it takes 4 /8 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address01110100.00000000.00000000.00000000116.0.0.0
Subnet mask11111100.00000000.00000000.00000000252.0.0.0
Network01110100.00000000.00000000.00000000116.0.0.0
Broadcast01110111.11111111.11111111.11111111119.255.255.255
Split into smaller subnets/13
/7 (2)/8 (4)/9 (8)/10 (16)/11 (32)/12 (64)/13 (128)/14 (256)/15 (512)/16 (1,024)/17 (2,048)/18 (4,096)

116.0.0.0/6 makes 128 subnets of /13.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1116.0.0.0/13116.0.0.1 to 116.7.255.254116.7.255.255524,286
2116.8.0.0/13116.8.0.1 to 116.15.255.254116.15.255.255524,286
3116.16.0.0/13116.16.0.1 to 116.23.255.254116.23.255.255524,286
4116.24.0.0/13116.24.0.1 to 116.31.255.254116.31.255.255524,286
5116.32.0.0/13116.32.0.1 to 116.39.255.254116.39.255.255524,286
6116.40.0.0/13116.40.0.1 to 116.47.255.254116.47.255.255524,286
7116.48.0.0/13116.48.0.1 to 116.55.255.254116.55.255.255524,286
8116.56.0.0/13116.56.0.1 to 116.63.255.254116.63.255.255524,286
9116.64.0.0/13116.64.0.1 to 116.71.255.254116.71.255.255524,286
10116.72.0.0/13116.72.0.1 to 116.79.255.254116.79.255.255524,286
11116.80.0.0/13116.80.0.1 to 116.87.255.254116.87.255.255524,286
12116.88.0.0/13116.88.0.1 to 116.95.255.254116.95.255.255524,286
13116.96.0.0/13116.96.0.1 to 116.103.255.254116.103.255.255524,286
14116.104.0.0/13116.104.0.1 to 116.111.255.254116.111.255.255524,286
15116.112.0.0/13116.112.0.1 to 116.119.255.254116.119.255.255524,286
16116.120.0.0/13116.120.0.1 to 116.127.255.254116.127.255.255524,286
17116.128.0.0/13116.128.0.1 to 116.135.255.254116.135.255.255524,286
18116.136.0.0/13116.136.0.1 to 116.143.255.254116.143.255.255524,286
19116.144.0.0/13116.144.0.1 to 116.151.255.254116.151.255.255524,286
20116.152.0.0/13116.152.0.1 to 116.159.255.254116.159.255.255524,286
21116.160.0.0/13116.160.0.1 to 116.167.255.254116.167.255.255524,286
22116.168.0.0/13116.168.0.1 to 116.175.255.254116.175.255.255524,286
23116.176.0.0/13116.176.0.1 to 116.183.255.254116.183.255.255524,286
24116.184.0.0/13116.184.0.1 to 116.191.255.254116.191.255.255524,286
25116.192.0.0/13116.192.0.1 to 116.199.255.254116.199.255.255524,286
26116.200.0.0/13116.200.0.1 to 116.207.255.254116.207.255.255524,286
27116.208.0.0/13116.208.0.1 to 116.215.255.254116.215.255.255524,286
28116.216.0.0/13116.216.0.1 to 116.223.255.254116.223.255.255524,286
29116.224.0.0/13116.224.0.1 to 116.231.255.254116.231.255.255524,286
30116.232.0.0/13116.232.0.1 to 116.239.255.254116.239.255.255524,286
31116.240.0.0/13116.240.0.1 to 116.247.255.254116.247.255.255524,286
32116.248.0.0/13116.248.0.1 to 116.255.255.254116.255.255.255524,286
33117.0.0.0/13117.0.0.1 to 117.7.255.254117.7.255.255524,286
34117.8.0.0/13117.8.0.1 to 117.15.255.254117.15.255.255524,286
35117.16.0.0/13117.16.0.1 to 117.23.255.254117.23.255.255524,286
36117.24.0.0/13117.24.0.1 to 117.31.255.254117.31.255.255524,286
37117.32.0.0/13117.32.0.1 to 117.39.255.254117.39.255.255524,286
38117.40.0.0/13117.40.0.1 to 117.47.255.254117.47.255.255524,286
39117.48.0.0/13117.48.0.1 to 117.55.255.254117.55.255.255524,286
40117.56.0.0/13117.56.0.1 to 117.63.255.254117.63.255.255524,286
41117.64.0.0/13117.64.0.1 to 117.71.255.254117.71.255.255524,286
42117.72.0.0/13117.72.0.1 to 117.79.255.254117.79.255.255524,286
43117.80.0.0/13117.80.0.1 to 117.87.255.254117.87.255.255524,286
44117.88.0.0/13117.88.0.1 to 117.95.255.254117.95.255.255524,286
45117.96.0.0/13117.96.0.1 to 117.103.255.254117.103.255.255524,286
46117.104.0.0/13117.104.0.1 to 117.111.255.254117.111.255.255524,286
47117.112.0.0/13117.112.0.1 to 117.119.255.254117.119.255.255524,286
48117.120.0.0/13117.120.0.1 to 117.127.255.254117.127.255.255524,286
49117.128.0.0/13117.128.0.1 to 117.135.255.254117.135.255.255524,286
50117.136.0.0/13117.136.0.1 to 117.143.255.254117.143.255.255524,286
51117.144.0.0/13117.144.0.1 to 117.151.255.254117.151.255.255524,286
52117.152.0.0/13117.152.0.1 to 117.159.255.254117.159.255.255524,286
53117.160.0.0/13117.160.0.1 to 117.167.255.254117.167.255.255524,286
54117.168.0.0/13117.168.0.1 to 117.175.255.254117.175.255.255524,286
55117.176.0.0/13117.176.0.1 to 117.183.255.254117.183.255.255524,286
56117.184.0.0/13117.184.0.1 to 117.191.255.254117.191.255.255524,286
57117.192.0.0/13117.192.0.1 to 117.199.255.254117.199.255.255524,286
58117.200.0.0/13117.200.0.1 to 117.207.255.254117.207.255.255524,286
59117.208.0.0/13117.208.0.1 to 117.215.255.254117.215.255.255524,286
60117.216.0.0/13117.216.0.1 to 117.223.255.254117.223.255.255524,286
61117.224.0.0/13117.224.0.1 to 117.231.255.254117.231.255.255524,286
62117.232.0.0/13117.232.0.1 to 117.239.255.254117.239.255.255524,286
63117.240.0.0/13117.240.0.1 to 117.247.255.254117.247.255.255524,286
64117.248.0.0/13117.248.0.1 to 117.255.255.254117.255.255.255524,286
65118.0.0.0/13118.0.0.1 to 118.7.255.254118.7.255.255524,286
66118.8.0.0/13118.8.0.1 to 118.15.255.254118.15.255.255524,286
67118.16.0.0/13118.16.0.1 to 118.23.255.254118.23.255.255524,286
68118.24.0.0/13118.24.0.1 to 118.31.255.254118.31.255.255524,286
69118.32.0.0/13118.32.0.1 to 118.39.255.254118.39.255.255524,286
70118.40.0.0/13118.40.0.1 to 118.47.255.254118.47.255.255524,286
71118.48.0.0/13118.48.0.1 to 118.55.255.254118.55.255.255524,286
72118.56.0.0/13118.56.0.1 to 118.63.255.254118.63.255.255524,286
73118.64.0.0/13118.64.0.1 to 118.71.255.254118.71.255.255524,286
74118.72.0.0/13118.72.0.1 to 118.79.255.254118.79.255.255524,286
75118.80.0.0/13118.80.0.1 to 118.87.255.254118.87.255.255524,286
76118.88.0.0/13118.88.0.1 to 118.95.255.254118.95.255.255524,286
77118.96.0.0/13118.96.0.1 to 118.103.255.254118.103.255.255524,286
78118.104.0.0/13118.104.0.1 to 118.111.255.254118.111.255.255524,286
79118.112.0.0/13118.112.0.1 to 118.119.255.254118.119.255.255524,286
80118.120.0.0/13118.120.0.1 to 118.127.255.254118.127.255.255524,286
81118.128.0.0/13118.128.0.1 to 118.135.255.254118.135.255.255524,286
82118.136.0.0/13118.136.0.1 to 118.143.255.254118.143.255.255524,286
83118.144.0.0/13118.144.0.1 to 118.151.255.254118.151.255.255524,286
84118.152.0.0/13118.152.0.1 to 118.159.255.254118.159.255.255524,286
85118.160.0.0/13118.160.0.1 to 118.167.255.254118.167.255.255524,286
86118.168.0.0/13118.168.0.1 to 118.175.255.254118.175.255.255524,286
87118.176.0.0/13118.176.0.1 to 118.183.255.254118.183.255.255524,286
88118.184.0.0/13118.184.0.1 to 118.191.255.254118.191.255.255524,286
89118.192.0.0/13118.192.0.1 to 118.199.255.254118.199.255.255524,286
90118.200.0.0/13118.200.0.1 to 118.207.255.254118.207.255.255524,286
91118.208.0.0/13118.208.0.1 to 118.215.255.254118.215.255.255524,286
92118.216.0.0/13118.216.0.1 to 118.223.255.254118.223.255.255524,286
93118.224.0.0/13118.224.0.1 to 118.231.255.254118.231.255.255524,286
94118.232.0.0/13118.232.0.1 to 118.239.255.254118.239.255.255524,286
95118.240.0.0/13118.240.0.1 to 118.247.255.254118.247.255.255524,286
96118.248.0.0/13118.248.0.1 to 118.255.255.254118.255.255.255524,286
97119.0.0.0/13119.0.0.1 to 119.7.255.254119.7.255.255524,286
98119.8.0.0/13119.8.0.1 to 119.15.255.254119.15.255.255524,286
99119.16.0.0/13119.16.0.1 to 119.23.255.254119.23.255.255524,286
100119.24.0.0/13119.24.0.1 to 119.31.255.254119.31.255.255524,286
101119.32.0.0/13119.32.0.1 to 119.39.255.254119.39.255.255524,286
102119.40.0.0/13119.40.0.1 to 119.47.255.254119.47.255.255524,286
103119.48.0.0/13119.48.0.1 to 119.55.255.254119.55.255.255524,286
104119.56.0.0/13119.56.0.1 to 119.63.255.254119.63.255.255524,286
105119.64.0.0/13119.64.0.1 to 119.71.255.254119.71.255.255524,286
106119.72.0.0/13119.72.0.1 to 119.79.255.254119.79.255.255524,286
107119.80.0.0/13119.80.0.1 to 119.87.255.254119.87.255.255524,286
108119.88.0.0/13119.88.0.1 to 119.95.255.254119.95.255.255524,286
109119.96.0.0/13119.96.0.1 to 119.103.255.254119.103.255.255524,286
110119.104.0.0/13119.104.0.1 to 119.111.255.254119.111.255.255524,286
111119.112.0.0/13119.112.0.1 to 119.119.255.254119.119.255.255524,286
112119.120.0.0/13119.120.0.1 to 119.127.255.254119.127.255.255524,286
113119.128.0.0/13119.128.0.1 to 119.135.255.254119.135.255.255524,286
114119.136.0.0/13119.136.0.1 to 119.143.255.254119.143.255.255524,286
115119.144.0.0/13119.144.0.1 to 119.151.255.254119.151.255.255524,286
116119.152.0.0/13119.152.0.1 to 119.159.255.254119.159.255.255524,286
117119.160.0.0/13119.160.0.1 to 119.167.255.254119.167.255.255524,286
118119.168.0.0/13119.168.0.1 to 119.175.255.254119.175.255.255524,286
119119.176.0.0/13119.176.0.1 to 119.183.255.254119.183.255.255524,286
120119.184.0.0/13119.184.0.1 to 119.191.255.254119.191.255.255524,286
121119.192.0.0/13119.192.0.1 to 119.199.255.254119.199.255.255524,286
122119.200.0.0/13119.200.0.1 to 119.207.255.254119.207.255.255524,286
123119.208.0.0/13119.208.0.1 to 119.215.255.254119.215.255.255524,286
124119.216.0.0/13119.216.0.1 to 119.223.255.254119.223.255.255524,286
125119.224.0.0/13119.224.0.1 to 119.231.255.254119.231.255.255524,286
126119.232.0.0/13119.232.0.1 to 119.239.255.254119.239.255.255524,286
127119.240.0.0/13119.240.0.1 to 119.247.255.254119.247.255.255524,286
128119.248.0.0/13119.248.0.1 to 119.255.255.254119.255.255.255524,286

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.