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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.

Network134.64.0.0/11
Usable hosts2,097,150
Subnet mask255.224.0.0
Addresses2,097,152
Network address
134.64.0.0
Broadcast address
134.95.255.255
First usable
134.64.0.1
Last usable
134.95.255.254
Usable hosts
2,097,150 (2,097,152 less the network and broadcast addresses)
Subnet mask
255.224.0.0
Wildcard mask
0.31.255.255 (Cisco ACLs, OSPF)
Prefix length
/11
Type
Public public
Old class
B (default /16)
As numbers
Hex 86400000 · Integer 2252341248 to 2254438399
Reverse DNS zones
64.134.in-addr.arpa
65.134.in-addr.arpa
66.134.in-addr.arpa
67.134.in-addr.arpa
68.134.in-addr.arpa
69.134.in-addr.arpa
70.134.in-addr.arpa
71.134.in-addr.arpa
72.134.in-addr.arpa
73.134.in-addr.arpa
74.134.in-addr.arpa
75.134.in-addr.arpa
76.134.in-addr.arpa
77.134.in-addr.arpa
78.134.in-addr.arpa
79.134.in-addr.arpa
and 16 more
/11 is not on a 8-bit boundary, so it takes 32 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address10000110.01000000.00000000.00000000134.64.0.0
Subnet mask11111111.11100000.00000000.00000000255.224.0.0
Network10000110.01000000.00000000.00000000134.64.0.0
Broadcast10000110.01011111.11111111.11111111134.95.255.255
Split into smaller subnets/18
/12 (2)/13 (4)/14 (8)/15 (16)/16 (32)/17 (64)/18 (128)/19 (256)/20 (512)/21 (1,024)/22 (2,048)/23 (4,096)

134.64.0.0/11 makes 128 subnets of /18.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1134.64.0.0/18134.64.0.1 to 134.64.63.254134.64.63.25516,382
2134.64.64.0/18134.64.64.1 to 134.64.127.254134.64.127.25516,382
3134.64.128.0/18134.64.128.1 to 134.64.191.254134.64.191.25516,382
4134.64.192.0/18134.64.192.1 to 134.64.255.254134.64.255.25516,382
5134.65.0.0/18134.65.0.1 to 134.65.63.254134.65.63.25516,382
6134.65.64.0/18134.65.64.1 to 134.65.127.254134.65.127.25516,382
7134.65.128.0/18134.65.128.1 to 134.65.191.254134.65.191.25516,382
8134.65.192.0/18134.65.192.1 to 134.65.255.254134.65.255.25516,382
9134.66.0.0/18134.66.0.1 to 134.66.63.254134.66.63.25516,382
10134.66.64.0/18134.66.64.1 to 134.66.127.254134.66.127.25516,382
11134.66.128.0/18134.66.128.1 to 134.66.191.254134.66.191.25516,382
12134.66.192.0/18134.66.192.1 to 134.66.255.254134.66.255.25516,382
13134.67.0.0/18134.67.0.1 to 134.67.63.254134.67.63.25516,382
14134.67.64.0/18134.67.64.1 to 134.67.127.254134.67.127.25516,382
15134.67.128.0/18134.67.128.1 to 134.67.191.254134.67.191.25516,382
16134.67.192.0/18134.67.192.1 to 134.67.255.254134.67.255.25516,382
17134.68.0.0/18134.68.0.1 to 134.68.63.254134.68.63.25516,382
18134.68.64.0/18134.68.64.1 to 134.68.127.254134.68.127.25516,382
19134.68.128.0/18134.68.128.1 to 134.68.191.254134.68.191.25516,382
20134.68.192.0/18134.68.192.1 to 134.68.255.254134.68.255.25516,382
21134.69.0.0/18134.69.0.1 to 134.69.63.254134.69.63.25516,382
22134.69.64.0/18134.69.64.1 to 134.69.127.254134.69.127.25516,382
23134.69.128.0/18134.69.128.1 to 134.69.191.254134.69.191.25516,382
24134.69.192.0/18134.69.192.1 to 134.69.255.254134.69.255.25516,382
25134.70.0.0/18134.70.0.1 to 134.70.63.254134.70.63.25516,382
26134.70.64.0/18134.70.64.1 to 134.70.127.254134.70.127.25516,382
27134.70.128.0/18134.70.128.1 to 134.70.191.254134.70.191.25516,382
28134.70.192.0/18134.70.192.1 to 134.70.255.254134.70.255.25516,382
29134.71.0.0/18134.71.0.1 to 134.71.63.254134.71.63.25516,382
30134.71.64.0/18134.71.64.1 to 134.71.127.254134.71.127.25516,382
31134.71.128.0/18134.71.128.1 to 134.71.191.254134.71.191.25516,382
32134.71.192.0/18134.71.192.1 to 134.71.255.254134.71.255.25516,382
33134.72.0.0/18134.72.0.1 to 134.72.63.254134.72.63.25516,382
34134.72.64.0/18134.72.64.1 to 134.72.127.254134.72.127.25516,382
35134.72.128.0/18134.72.128.1 to 134.72.191.254134.72.191.25516,382
36134.72.192.0/18134.72.192.1 to 134.72.255.254134.72.255.25516,382
37134.73.0.0/18134.73.0.1 to 134.73.63.254134.73.63.25516,382
38134.73.64.0/18134.73.64.1 to 134.73.127.254134.73.127.25516,382
39134.73.128.0/18134.73.128.1 to 134.73.191.254134.73.191.25516,382
40134.73.192.0/18134.73.192.1 to 134.73.255.254134.73.255.25516,382
41134.74.0.0/18134.74.0.1 to 134.74.63.254134.74.63.25516,382
42134.74.64.0/18134.74.64.1 to 134.74.127.254134.74.127.25516,382
43134.74.128.0/18134.74.128.1 to 134.74.191.254134.74.191.25516,382
44134.74.192.0/18134.74.192.1 to 134.74.255.254134.74.255.25516,382
45134.75.0.0/18134.75.0.1 to 134.75.63.254134.75.63.25516,382
46134.75.64.0/18134.75.64.1 to 134.75.127.254134.75.127.25516,382
47134.75.128.0/18134.75.128.1 to 134.75.191.254134.75.191.25516,382
48134.75.192.0/18134.75.192.1 to 134.75.255.254134.75.255.25516,382
49134.76.0.0/18134.76.0.1 to 134.76.63.254134.76.63.25516,382
50134.76.64.0/18134.76.64.1 to 134.76.127.254134.76.127.25516,382
51134.76.128.0/18134.76.128.1 to 134.76.191.254134.76.191.25516,382
52134.76.192.0/18134.76.192.1 to 134.76.255.254134.76.255.25516,382
53134.77.0.0/18134.77.0.1 to 134.77.63.254134.77.63.25516,382
54134.77.64.0/18134.77.64.1 to 134.77.127.254134.77.127.25516,382
55134.77.128.0/18134.77.128.1 to 134.77.191.254134.77.191.25516,382
56134.77.192.0/18134.77.192.1 to 134.77.255.254134.77.255.25516,382
57134.78.0.0/18134.78.0.1 to 134.78.63.254134.78.63.25516,382
58134.78.64.0/18134.78.64.1 to 134.78.127.254134.78.127.25516,382
59134.78.128.0/18134.78.128.1 to 134.78.191.254134.78.191.25516,382
60134.78.192.0/18134.78.192.1 to 134.78.255.254134.78.255.25516,382
61134.79.0.0/18134.79.0.1 to 134.79.63.254134.79.63.25516,382
62134.79.64.0/18134.79.64.1 to 134.79.127.254134.79.127.25516,382
63134.79.128.0/18134.79.128.1 to 134.79.191.254134.79.191.25516,382
64134.79.192.0/18134.79.192.1 to 134.79.255.254134.79.255.25516,382
65134.80.0.0/18134.80.0.1 to 134.80.63.254134.80.63.25516,382
66134.80.64.0/18134.80.64.1 to 134.80.127.254134.80.127.25516,382
67134.80.128.0/18134.80.128.1 to 134.80.191.254134.80.191.25516,382
68134.80.192.0/18134.80.192.1 to 134.80.255.254134.80.255.25516,382
69134.81.0.0/18134.81.0.1 to 134.81.63.254134.81.63.25516,382
70134.81.64.0/18134.81.64.1 to 134.81.127.254134.81.127.25516,382
71134.81.128.0/18134.81.128.1 to 134.81.191.254134.81.191.25516,382
72134.81.192.0/18134.81.192.1 to 134.81.255.254134.81.255.25516,382
73134.82.0.0/18134.82.0.1 to 134.82.63.254134.82.63.25516,382
74134.82.64.0/18134.82.64.1 to 134.82.127.254134.82.127.25516,382
75134.82.128.0/18134.82.128.1 to 134.82.191.254134.82.191.25516,382
76134.82.192.0/18134.82.192.1 to 134.82.255.254134.82.255.25516,382
77134.83.0.0/18134.83.0.1 to 134.83.63.254134.83.63.25516,382
78134.83.64.0/18134.83.64.1 to 134.83.127.254134.83.127.25516,382
79134.83.128.0/18134.83.128.1 to 134.83.191.254134.83.191.25516,382
80134.83.192.0/18134.83.192.1 to 134.83.255.254134.83.255.25516,382
81134.84.0.0/18134.84.0.1 to 134.84.63.254134.84.63.25516,382
82134.84.64.0/18134.84.64.1 to 134.84.127.254134.84.127.25516,382
83134.84.128.0/18134.84.128.1 to 134.84.191.254134.84.191.25516,382
84134.84.192.0/18134.84.192.1 to 134.84.255.254134.84.255.25516,382
85134.85.0.0/18134.85.0.1 to 134.85.63.254134.85.63.25516,382
86134.85.64.0/18134.85.64.1 to 134.85.127.254134.85.127.25516,382
87134.85.128.0/18134.85.128.1 to 134.85.191.254134.85.191.25516,382
88134.85.192.0/18134.85.192.1 to 134.85.255.254134.85.255.25516,382
89134.86.0.0/18134.86.0.1 to 134.86.63.254134.86.63.25516,382
90134.86.64.0/18134.86.64.1 to 134.86.127.254134.86.127.25516,382
91134.86.128.0/18134.86.128.1 to 134.86.191.254134.86.191.25516,382
92134.86.192.0/18134.86.192.1 to 134.86.255.254134.86.255.25516,382
93134.87.0.0/18134.87.0.1 to 134.87.63.254134.87.63.25516,382
94134.87.64.0/18134.87.64.1 to 134.87.127.254134.87.127.25516,382
95134.87.128.0/18134.87.128.1 to 134.87.191.254134.87.191.25516,382
96134.87.192.0/18134.87.192.1 to 134.87.255.254134.87.255.25516,382
97134.88.0.0/18134.88.0.1 to 134.88.63.254134.88.63.25516,382
98134.88.64.0/18134.88.64.1 to 134.88.127.254134.88.127.25516,382
99134.88.128.0/18134.88.128.1 to 134.88.191.254134.88.191.25516,382
100134.88.192.0/18134.88.192.1 to 134.88.255.254134.88.255.25516,382
101134.89.0.0/18134.89.0.1 to 134.89.63.254134.89.63.25516,382
102134.89.64.0/18134.89.64.1 to 134.89.127.254134.89.127.25516,382
103134.89.128.0/18134.89.128.1 to 134.89.191.254134.89.191.25516,382
104134.89.192.0/18134.89.192.1 to 134.89.255.254134.89.255.25516,382
105134.90.0.0/18134.90.0.1 to 134.90.63.254134.90.63.25516,382
106134.90.64.0/18134.90.64.1 to 134.90.127.254134.90.127.25516,382
107134.90.128.0/18134.90.128.1 to 134.90.191.254134.90.191.25516,382
108134.90.192.0/18134.90.192.1 to 134.90.255.254134.90.255.25516,382
109134.91.0.0/18134.91.0.1 to 134.91.63.254134.91.63.25516,382
110134.91.64.0/18134.91.64.1 to 134.91.127.254134.91.127.25516,382
111134.91.128.0/18134.91.128.1 to 134.91.191.254134.91.191.25516,382
112134.91.192.0/18134.91.192.1 to 134.91.255.254134.91.255.25516,382
113134.92.0.0/18134.92.0.1 to 134.92.63.254134.92.63.25516,382
114134.92.64.0/18134.92.64.1 to 134.92.127.254134.92.127.25516,382
115134.92.128.0/18134.92.128.1 to 134.92.191.254134.92.191.25516,382
116134.92.192.0/18134.92.192.1 to 134.92.255.254134.92.255.25516,382
117134.93.0.0/18134.93.0.1 to 134.93.63.254134.93.63.25516,382
118134.93.64.0/18134.93.64.1 to 134.93.127.254134.93.127.25516,382
119134.93.128.0/18134.93.128.1 to 134.93.191.254134.93.191.25516,382
120134.93.192.0/18134.93.192.1 to 134.93.255.254134.93.255.25516,382
121134.94.0.0/18134.94.0.1 to 134.94.63.254134.94.63.25516,382
122134.94.64.0/18134.94.64.1 to 134.94.127.254134.94.127.25516,382
123134.94.128.0/18134.94.128.1 to 134.94.191.254134.94.191.25516,382
124134.94.192.0/18134.94.192.1 to 134.94.255.254134.94.255.25516,382
125134.95.0.0/18134.95.0.1 to 134.95.63.254134.95.63.25516,382
126134.95.64.0/18134.95.64.1 to 134.95.127.254134.95.127.25516,382
127134.95.128.0/18134.95.128.1 to 134.95.191.254134.95.191.25516,382
128134.95.192.0/18134.95.192.1 to 134.95.255.254134.95.255.25516,382

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.