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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.

Network196.232.0.0/13
Usable hosts524,286
Subnet mask255.248.0.0
Addresses524,288
Network address
196.232.0.0
Broadcast address
196.239.255.255
First usable
196.232.0.1
Last usable
196.239.255.254
Usable hosts
524,286 (524,288 less the network and broadcast addresses)
Subnet mask
255.248.0.0
Wildcard mask
0.7.255.255 (Cisco ACLs, OSPF)
Prefix length
/13
Type
Public public
Old class
C (default /24)
As numbers
Hex C4E80000 · Integer 3303538688 to 3304062975
Reverse DNS zones
232.196.in-addr.arpa
233.196.in-addr.arpa
234.196.in-addr.arpa
235.196.in-addr.arpa
236.196.in-addr.arpa
237.196.in-addr.arpa
238.196.in-addr.arpa
239.196.in-addr.arpa
/13 is not on a 8-bit boundary, so it takes 8 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address11000100.11101000.00000000.00000000196.232.0.0
Subnet mask11111111.11111000.00000000.00000000255.248.0.0
Network11000100.11101000.00000000.00000000196.232.0.0
Broadcast11000100.11101111.11111111.11111111196.239.255.255
Split into smaller subnets/20
/14 (2)/15 (4)/16 (8)/17 (16)/18 (32)/19 (64)/20 (128)/21 (256)/22 (512)/23 (1,024)/24 (2,048)/25 (4,096)

196.232.0.0/13 makes 128 subnets of /20.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1196.232.0.0/20196.232.0.1 to 196.232.15.254196.232.15.2554,094
2196.232.16.0/20196.232.16.1 to 196.232.31.254196.232.31.2554,094
3196.232.32.0/20196.232.32.1 to 196.232.47.254196.232.47.2554,094
4196.232.48.0/20196.232.48.1 to 196.232.63.254196.232.63.2554,094
5196.232.64.0/20196.232.64.1 to 196.232.79.254196.232.79.2554,094
6196.232.80.0/20196.232.80.1 to 196.232.95.254196.232.95.2554,094
7196.232.96.0/20196.232.96.1 to 196.232.111.254196.232.111.2554,094
8196.232.112.0/20196.232.112.1 to 196.232.127.254196.232.127.2554,094
9196.232.128.0/20196.232.128.1 to 196.232.143.254196.232.143.2554,094
10196.232.144.0/20196.232.144.1 to 196.232.159.254196.232.159.2554,094
11196.232.160.0/20196.232.160.1 to 196.232.175.254196.232.175.2554,094
12196.232.176.0/20196.232.176.1 to 196.232.191.254196.232.191.2554,094
13196.232.192.0/20196.232.192.1 to 196.232.207.254196.232.207.2554,094
14196.232.208.0/20196.232.208.1 to 196.232.223.254196.232.223.2554,094
15196.232.224.0/20196.232.224.1 to 196.232.239.254196.232.239.2554,094
16196.232.240.0/20196.232.240.1 to 196.232.255.254196.232.255.2554,094
17196.233.0.0/20196.233.0.1 to 196.233.15.254196.233.15.2554,094
18196.233.16.0/20196.233.16.1 to 196.233.31.254196.233.31.2554,094
19196.233.32.0/20196.233.32.1 to 196.233.47.254196.233.47.2554,094
20196.233.48.0/20196.233.48.1 to 196.233.63.254196.233.63.2554,094
21196.233.64.0/20196.233.64.1 to 196.233.79.254196.233.79.2554,094
22196.233.80.0/20196.233.80.1 to 196.233.95.254196.233.95.2554,094
23196.233.96.0/20196.233.96.1 to 196.233.111.254196.233.111.2554,094
24196.233.112.0/20196.233.112.1 to 196.233.127.254196.233.127.2554,094
25196.233.128.0/20196.233.128.1 to 196.233.143.254196.233.143.2554,094
26196.233.144.0/20196.233.144.1 to 196.233.159.254196.233.159.2554,094
27196.233.160.0/20196.233.160.1 to 196.233.175.254196.233.175.2554,094
28196.233.176.0/20196.233.176.1 to 196.233.191.254196.233.191.2554,094
29196.233.192.0/20196.233.192.1 to 196.233.207.254196.233.207.2554,094
30196.233.208.0/20196.233.208.1 to 196.233.223.254196.233.223.2554,094
31196.233.224.0/20196.233.224.1 to 196.233.239.254196.233.239.2554,094
32196.233.240.0/20196.233.240.1 to 196.233.255.254196.233.255.2554,094
33196.234.0.0/20196.234.0.1 to 196.234.15.254196.234.15.2554,094
34196.234.16.0/20196.234.16.1 to 196.234.31.254196.234.31.2554,094
35196.234.32.0/20196.234.32.1 to 196.234.47.254196.234.47.2554,094
36196.234.48.0/20196.234.48.1 to 196.234.63.254196.234.63.2554,094
37196.234.64.0/20196.234.64.1 to 196.234.79.254196.234.79.2554,094
38196.234.80.0/20196.234.80.1 to 196.234.95.254196.234.95.2554,094
39196.234.96.0/20196.234.96.1 to 196.234.111.254196.234.111.2554,094
40196.234.112.0/20196.234.112.1 to 196.234.127.254196.234.127.2554,094
41196.234.128.0/20196.234.128.1 to 196.234.143.254196.234.143.2554,094
42196.234.144.0/20196.234.144.1 to 196.234.159.254196.234.159.2554,094
43196.234.160.0/20196.234.160.1 to 196.234.175.254196.234.175.2554,094
44196.234.176.0/20196.234.176.1 to 196.234.191.254196.234.191.2554,094
45196.234.192.0/20196.234.192.1 to 196.234.207.254196.234.207.2554,094
46196.234.208.0/20196.234.208.1 to 196.234.223.254196.234.223.2554,094
47196.234.224.0/20196.234.224.1 to 196.234.239.254196.234.239.2554,094
48196.234.240.0/20196.234.240.1 to 196.234.255.254196.234.255.2554,094
49196.235.0.0/20196.235.0.1 to 196.235.15.254196.235.15.2554,094
50196.235.16.0/20196.235.16.1 to 196.235.31.254196.235.31.2554,094
51196.235.32.0/20196.235.32.1 to 196.235.47.254196.235.47.2554,094
52196.235.48.0/20196.235.48.1 to 196.235.63.254196.235.63.2554,094
53196.235.64.0/20196.235.64.1 to 196.235.79.254196.235.79.2554,094
54196.235.80.0/20196.235.80.1 to 196.235.95.254196.235.95.2554,094
55196.235.96.0/20196.235.96.1 to 196.235.111.254196.235.111.2554,094
56196.235.112.0/20196.235.112.1 to 196.235.127.254196.235.127.2554,094
57196.235.128.0/20196.235.128.1 to 196.235.143.254196.235.143.2554,094
58196.235.144.0/20196.235.144.1 to 196.235.159.254196.235.159.2554,094
59196.235.160.0/20196.235.160.1 to 196.235.175.254196.235.175.2554,094
60196.235.176.0/20196.235.176.1 to 196.235.191.254196.235.191.2554,094
61196.235.192.0/20196.235.192.1 to 196.235.207.254196.235.207.2554,094
62196.235.208.0/20196.235.208.1 to 196.235.223.254196.235.223.2554,094
63196.235.224.0/20196.235.224.1 to 196.235.239.254196.235.239.2554,094
64196.235.240.0/20196.235.240.1 to 196.235.255.254196.235.255.2554,094
65196.236.0.0/20196.236.0.1 to 196.236.15.254196.236.15.2554,094
66196.236.16.0/20196.236.16.1 to 196.236.31.254196.236.31.2554,094
67196.236.32.0/20196.236.32.1 to 196.236.47.254196.236.47.2554,094
68196.236.48.0/20196.236.48.1 to 196.236.63.254196.236.63.2554,094
69196.236.64.0/20196.236.64.1 to 196.236.79.254196.236.79.2554,094
70196.236.80.0/20196.236.80.1 to 196.236.95.254196.236.95.2554,094
71196.236.96.0/20196.236.96.1 to 196.236.111.254196.236.111.2554,094
72196.236.112.0/20196.236.112.1 to 196.236.127.254196.236.127.2554,094
73196.236.128.0/20196.236.128.1 to 196.236.143.254196.236.143.2554,094
74196.236.144.0/20196.236.144.1 to 196.236.159.254196.236.159.2554,094
75196.236.160.0/20196.236.160.1 to 196.236.175.254196.236.175.2554,094
76196.236.176.0/20196.236.176.1 to 196.236.191.254196.236.191.2554,094
77196.236.192.0/20196.236.192.1 to 196.236.207.254196.236.207.2554,094
78196.236.208.0/20196.236.208.1 to 196.236.223.254196.236.223.2554,094
79196.236.224.0/20196.236.224.1 to 196.236.239.254196.236.239.2554,094
80196.236.240.0/20196.236.240.1 to 196.236.255.254196.236.255.2554,094
81196.237.0.0/20196.237.0.1 to 196.237.15.254196.237.15.2554,094
82196.237.16.0/20196.237.16.1 to 196.237.31.254196.237.31.2554,094
83196.237.32.0/20196.237.32.1 to 196.237.47.254196.237.47.2554,094
84196.237.48.0/20196.237.48.1 to 196.237.63.254196.237.63.2554,094
85196.237.64.0/20196.237.64.1 to 196.237.79.254196.237.79.2554,094
86196.237.80.0/20196.237.80.1 to 196.237.95.254196.237.95.2554,094
87196.237.96.0/20196.237.96.1 to 196.237.111.254196.237.111.2554,094
88196.237.112.0/20196.237.112.1 to 196.237.127.254196.237.127.2554,094
89196.237.128.0/20196.237.128.1 to 196.237.143.254196.237.143.2554,094
90196.237.144.0/20196.237.144.1 to 196.237.159.254196.237.159.2554,094
91196.237.160.0/20196.237.160.1 to 196.237.175.254196.237.175.2554,094
92196.237.176.0/20196.237.176.1 to 196.237.191.254196.237.191.2554,094
93196.237.192.0/20196.237.192.1 to 196.237.207.254196.237.207.2554,094
94196.237.208.0/20196.237.208.1 to 196.237.223.254196.237.223.2554,094
95196.237.224.0/20196.237.224.1 to 196.237.239.254196.237.239.2554,094
96196.237.240.0/20196.237.240.1 to 196.237.255.254196.237.255.2554,094
97196.238.0.0/20196.238.0.1 to 196.238.15.254196.238.15.2554,094
98196.238.16.0/20196.238.16.1 to 196.238.31.254196.238.31.2554,094
99196.238.32.0/20196.238.32.1 to 196.238.47.254196.238.47.2554,094
100196.238.48.0/20196.238.48.1 to 196.238.63.254196.238.63.2554,094
101196.238.64.0/20196.238.64.1 to 196.238.79.254196.238.79.2554,094
102196.238.80.0/20196.238.80.1 to 196.238.95.254196.238.95.2554,094
103196.238.96.0/20196.238.96.1 to 196.238.111.254196.238.111.2554,094
104196.238.112.0/20196.238.112.1 to 196.238.127.254196.238.127.2554,094
105196.238.128.0/20196.238.128.1 to 196.238.143.254196.238.143.2554,094
106196.238.144.0/20196.238.144.1 to 196.238.159.254196.238.159.2554,094
107196.238.160.0/20196.238.160.1 to 196.238.175.254196.238.175.2554,094
108196.238.176.0/20196.238.176.1 to 196.238.191.254196.238.191.2554,094
109196.238.192.0/20196.238.192.1 to 196.238.207.254196.238.207.2554,094
110196.238.208.0/20196.238.208.1 to 196.238.223.254196.238.223.2554,094
111196.238.224.0/20196.238.224.1 to 196.238.239.254196.238.239.2554,094
112196.238.240.0/20196.238.240.1 to 196.238.255.254196.238.255.2554,094
113196.239.0.0/20196.239.0.1 to 196.239.15.254196.239.15.2554,094
114196.239.16.0/20196.239.16.1 to 196.239.31.254196.239.31.2554,094
115196.239.32.0/20196.239.32.1 to 196.239.47.254196.239.47.2554,094
116196.239.48.0/20196.239.48.1 to 196.239.63.254196.239.63.2554,094
117196.239.64.0/20196.239.64.1 to 196.239.79.254196.239.79.2554,094
118196.239.80.0/20196.239.80.1 to 196.239.95.254196.239.95.2554,094
119196.239.96.0/20196.239.96.1 to 196.239.111.254196.239.111.2554,094
120196.239.112.0/20196.239.112.1 to 196.239.127.254196.239.127.2554,094
121196.239.128.0/20196.239.128.1 to 196.239.143.254196.239.143.2554,094
122196.239.144.0/20196.239.144.1 to 196.239.159.254196.239.159.2554,094
123196.239.160.0/20196.239.160.1 to 196.239.175.254196.239.175.2554,094
124196.239.176.0/20196.239.176.1 to 196.239.191.254196.239.191.2554,094
125196.239.192.0/20196.239.192.1 to 196.239.207.254196.239.207.2554,094
126196.239.208.0/20196.239.208.1 to 196.239.223.254196.239.223.2554,094
127196.239.224.0/20196.239.224.1 to 196.239.239.254196.239.239.2554,094
128196.239.240.0/20196.239.240.1 to 196.239.255.254196.239.255.2554,094

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.