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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.

Network150.64.0.0/13
Usable hosts524,286
Subnet mask255.248.0.0
Addresses524,288
Network address
150.64.0.0
Broadcast address
150.71.255.255
First usable
150.64.0.1
Last usable
150.71.255.254
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
B (default /16)
As numbers
Hex 96400000 · Integer 2520776704 to 2521300991
Reverse DNS zones
64.150.in-addr.arpa
65.150.in-addr.arpa
66.150.in-addr.arpa
67.150.in-addr.arpa
68.150.in-addr.arpa
69.150.in-addr.arpa
70.150.in-addr.arpa
71.150.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
Address10010110.01000000.00000000.00000000150.64.0.0
Subnet mask11111111.11111000.00000000.00000000255.248.0.0
Network10010110.01000000.00000000.00000000150.64.0.0
Broadcast10010110.01000111.11111111.11111111150.71.255.255
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)

150.64.0.0/13 makes 128 subnets of /20.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1150.64.0.0/20150.64.0.1 to 150.64.15.254150.64.15.2554,094
2150.64.16.0/20150.64.16.1 to 150.64.31.254150.64.31.2554,094
3150.64.32.0/20150.64.32.1 to 150.64.47.254150.64.47.2554,094
4150.64.48.0/20150.64.48.1 to 150.64.63.254150.64.63.2554,094
5150.64.64.0/20150.64.64.1 to 150.64.79.254150.64.79.2554,094
6150.64.80.0/20150.64.80.1 to 150.64.95.254150.64.95.2554,094
7150.64.96.0/20150.64.96.1 to 150.64.111.254150.64.111.2554,094
8150.64.112.0/20150.64.112.1 to 150.64.127.254150.64.127.2554,094
9150.64.128.0/20150.64.128.1 to 150.64.143.254150.64.143.2554,094
10150.64.144.0/20150.64.144.1 to 150.64.159.254150.64.159.2554,094
11150.64.160.0/20150.64.160.1 to 150.64.175.254150.64.175.2554,094
12150.64.176.0/20150.64.176.1 to 150.64.191.254150.64.191.2554,094
13150.64.192.0/20150.64.192.1 to 150.64.207.254150.64.207.2554,094
14150.64.208.0/20150.64.208.1 to 150.64.223.254150.64.223.2554,094
15150.64.224.0/20150.64.224.1 to 150.64.239.254150.64.239.2554,094
16150.64.240.0/20150.64.240.1 to 150.64.255.254150.64.255.2554,094
17150.65.0.0/20150.65.0.1 to 150.65.15.254150.65.15.2554,094
18150.65.16.0/20150.65.16.1 to 150.65.31.254150.65.31.2554,094
19150.65.32.0/20150.65.32.1 to 150.65.47.254150.65.47.2554,094
20150.65.48.0/20150.65.48.1 to 150.65.63.254150.65.63.2554,094
21150.65.64.0/20150.65.64.1 to 150.65.79.254150.65.79.2554,094
22150.65.80.0/20150.65.80.1 to 150.65.95.254150.65.95.2554,094
23150.65.96.0/20150.65.96.1 to 150.65.111.254150.65.111.2554,094
24150.65.112.0/20150.65.112.1 to 150.65.127.254150.65.127.2554,094
25150.65.128.0/20150.65.128.1 to 150.65.143.254150.65.143.2554,094
26150.65.144.0/20150.65.144.1 to 150.65.159.254150.65.159.2554,094
27150.65.160.0/20150.65.160.1 to 150.65.175.254150.65.175.2554,094
28150.65.176.0/20150.65.176.1 to 150.65.191.254150.65.191.2554,094
29150.65.192.0/20150.65.192.1 to 150.65.207.254150.65.207.2554,094
30150.65.208.0/20150.65.208.1 to 150.65.223.254150.65.223.2554,094
31150.65.224.0/20150.65.224.1 to 150.65.239.254150.65.239.2554,094
32150.65.240.0/20150.65.240.1 to 150.65.255.254150.65.255.2554,094
33150.66.0.0/20150.66.0.1 to 150.66.15.254150.66.15.2554,094
34150.66.16.0/20150.66.16.1 to 150.66.31.254150.66.31.2554,094
35150.66.32.0/20150.66.32.1 to 150.66.47.254150.66.47.2554,094
36150.66.48.0/20150.66.48.1 to 150.66.63.254150.66.63.2554,094
37150.66.64.0/20150.66.64.1 to 150.66.79.254150.66.79.2554,094
38150.66.80.0/20150.66.80.1 to 150.66.95.254150.66.95.2554,094
39150.66.96.0/20150.66.96.1 to 150.66.111.254150.66.111.2554,094
40150.66.112.0/20150.66.112.1 to 150.66.127.254150.66.127.2554,094
41150.66.128.0/20150.66.128.1 to 150.66.143.254150.66.143.2554,094
42150.66.144.0/20150.66.144.1 to 150.66.159.254150.66.159.2554,094
43150.66.160.0/20150.66.160.1 to 150.66.175.254150.66.175.2554,094
44150.66.176.0/20150.66.176.1 to 150.66.191.254150.66.191.2554,094
45150.66.192.0/20150.66.192.1 to 150.66.207.254150.66.207.2554,094
46150.66.208.0/20150.66.208.1 to 150.66.223.254150.66.223.2554,094
47150.66.224.0/20150.66.224.1 to 150.66.239.254150.66.239.2554,094
48150.66.240.0/20150.66.240.1 to 150.66.255.254150.66.255.2554,094
49150.67.0.0/20150.67.0.1 to 150.67.15.254150.67.15.2554,094
50150.67.16.0/20150.67.16.1 to 150.67.31.254150.67.31.2554,094
51150.67.32.0/20150.67.32.1 to 150.67.47.254150.67.47.2554,094
52150.67.48.0/20150.67.48.1 to 150.67.63.254150.67.63.2554,094
53150.67.64.0/20150.67.64.1 to 150.67.79.254150.67.79.2554,094
54150.67.80.0/20150.67.80.1 to 150.67.95.254150.67.95.2554,094
55150.67.96.0/20150.67.96.1 to 150.67.111.254150.67.111.2554,094
56150.67.112.0/20150.67.112.1 to 150.67.127.254150.67.127.2554,094
57150.67.128.0/20150.67.128.1 to 150.67.143.254150.67.143.2554,094
58150.67.144.0/20150.67.144.1 to 150.67.159.254150.67.159.2554,094
59150.67.160.0/20150.67.160.1 to 150.67.175.254150.67.175.2554,094
60150.67.176.0/20150.67.176.1 to 150.67.191.254150.67.191.2554,094
61150.67.192.0/20150.67.192.1 to 150.67.207.254150.67.207.2554,094
62150.67.208.0/20150.67.208.1 to 150.67.223.254150.67.223.2554,094
63150.67.224.0/20150.67.224.1 to 150.67.239.254150.67.239.2554,094
64150.67.240.0/20150.67.240.1 to 150.67.255.254150.67.255.2554,094
65150.68.0.0/20150.68.0.1 to 150.68.15.254150.68.15.2554,094
66150.68.16.0/20150.68.16.1 to 150.68.31.254150.68.31.2554,094
67150.68.32.0/20150.68.32.1 to 150.68.47.254150.68.47.2554,094
68150.68.48.0/20150.68.48.1 to 150.68.63.254150.68.63.2554,094
69150.68.64.0/20150.68.64.1 to 150.68.79.254150.68.79.2554,094
70150.68.80.0/20150.68.80.1 to 150.68.95.254150.68.95.2554,094
71150.68.96.0/20150.68.96.1 to 150.68.111.254150.68.111.2554,094
72150.68.112.0/20150.68.112.1 to 150.68.127.254150.68.127.2554,094
73150.68.128.0/20150.68.128.1 to 150.68.143.254150.68.143.2554,094
74150.68.144.0/20150.68.144.1 to 150.68.159.254150.68.159.2554,094
75150.68.160.0/20150.68.160.1 to 150.68.175.254150.68.175.2554,094
76150.68.176.0/20150.68.176.1 to 150.68.191.254150.68.191.2554,094
77150.68.192.0/20150.68.192.1 to 150.68.207.254150.68.207.2554,094
78150.68.208.0/20150.68.208.1 to 150.68.223.254150.68.223.2554,094
79150.68.224.0/20150.68.224.1 to 150.68.239.254150.68.239.2554,094
80150.68.240.0/20150.68.240.1 to 150.68.255.254150.68.255.2554,094
81150.69.0.0/20150.69.0.1 to 150.69.15.254150.69.15.2554,094
82150.69.16.0/20150.69.16.1 to 150.69.31.254150.69.31.2554,094
83150.69.32.0/20150.69.32.1 to 150.69.47.254150.69.47.2554,094
84150.69.48.0/20150.69.48.1 to 150.69.63.254150.69.63.2554,094
85150.69.64.0/20150.69.64.1 to 150.69.79.254150.69.79.2554,094
86150.69.80.0/20150.69.80.1 to 150.69.95.254150.69.95.2554,094
87150.69.96.0/20150.69.96.1 to 150.69.111.254150.69.111.2554,094
88150.69.112.0/20150.69.112.1 to 150.69.127.254150.69.127.2554,094
89150.69.128.0/20150.69.128.1 to 150.69.143.254150.69.143.2554,094
90150.69.144.0/20150.69.144.1 to 150.69.159.254150.69.159.2554,094
91150.69.160.0/20150.69.160.1 to 150.69.175.254150.69.175.2554,094
92150.69.176.0/20150.69.176.1 to 150.69.191.254150.69.191.2554,094
93150.69.192.0/20150.69.192.1 to 150.69.207.254150.69.207.2554,094
94150.69.208.0/20150.69.208.1 to 150.69.223.254150.69.223.2554,094
95150.69.224.0/20150.69.224.1 to 150.69.239.254150.69.239.2554,094
96150.69.240.0/20150.69.240.1 to 150.69.255.254150.69.255.2554,094
97150.70.0.0/20150.70.0.1 to 150.70.15.254150.70.15.2554,094
98150.70.16.0/20150.70.16.1 to 150.70.31.254150.70.31.2554,094
99150.70.32.0/20150.70.32.1 to 150.70.47.254150.70.47.2554,094
100150.70.48.0/20150.70.48.1 to 150.70.63.254150.70.63.2554,094
101150.70.64.0/20150.70.64.1 to 150.70.79.254150.70.79.2554,094
102150.70.80.0/20150.70.80.1 to 150.70.95.254150.70.95.2554,094
103150.70.96.0/20150.70.96.1 to 150.70.111.254150.70.111.2554,094
104150.70.112.0/20150.70.112.1 to 150.70.127.254150.70.127.2554,094
105150.70.128.0/20150.70.128.1 to 150.70.143.254150.70.143.2554,094
106150.70.144.0/20150.70.144.1 to 150.70.159.254150.70.159.2554,094
107150.70.160.0/20150.70.160.1 to 150.70.175.254150.70.175.2554,094
108150.70.176.0/20150.70.176.1 to 150.70.191.254150.70.191.2554,094
109150.70.192.0/20150.70.192.1 to 150.70.207.254150.70.207.2554,094
110150.70.208.0/20150.70.208.1 to 150.70.223.254150.70.223.2554,094
111150.70.224.0/20150.70.224.1 to 150.70.239.254150.70.239.2554,094
112150.70.240.0/20150.70.240.1 to 150.70.255.254150.70.255.2554,094
113150.71.0.0/20150.71.0.1 to 150.71.15.254150.71.15.2554,094
114150.71.16.0/20150.71.16.1 to 150.71.31.254150.71.31.2554,094
115150.71.32.0/20150.71.32.1 to 150.71.47.254150.71.47.2554,094
116150.71.48.0/20150.71.48.1 to 150.71.63.254150.71.63.2554,094
117150.71.64.0/20150.71.64.1 to 150.71.79.254150.71.79.2554,094
118150.71.80.0/20150.71.80.1 to 150.71.95.254150.71.95.2554,094
119150.71.96.0/20150.71.96.1 to 150.71.111.254150.71.111.2554,094
120150.71.112.0/20150.71.112.1 to 150.71.127.254150.71.127.2554,094
121150.71.128.0/20150.71.128.1 to 150.71.143.254150.71.143.2554,094
122150.71.144.0/20150.71.144.1 to 150.71.159.254150.71.159.2554,094
123150.71.160.0/20150.71.160.1 to 150.71.175.254150.71.175.2554,094
124150.71.176.0/20150.71.176.1 to 150.71.191.254150.71.191.2554,094
125150.71.192.0/20150.71.192.1 to 150.71.207.254150.71.207.2554,094
126150.71.208.0/20150.71.208.1 to 150.71.223.254150.71.223.2554,094
127150.71.224.0/20150.71.224.1 to 150.71.239.254150.71.239.2554,094
128150.71.240.0/20150.71.240.1 to 150.71.255.254150.71.255.2554,094

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.