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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.

Network150.64.0.0/10
Usable hosts4,194,302
Subnet mask255.192.0.0
Addresses4,194,304
Network address
150.64.0.0
Broadcast address
150.127.255.255
First usable
150.64.0.1
Last usable
150.127.255.254
Usable hosts
4,194,302 (4,194,304 less the network and broadcast addresses)
Subnet mask
255.192.0.0
Wildcard mask
0.63.255.255 (Cisco ACLs, OSPF)
Prefix length
/10
Type
Public public
Old class
B (default /16)
As numbers
Hex 96400000 · Integer 2520776704 to 2524971007
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
72.150.in-addr.arpa
73.150.in-addr.arpa
74.150.in-addr.arpa
75.150.in-addr.arpa
76.150.in-addr.arpa
77.150.in-addr.arpa
78.150.in-addr.arpa
79.150.in-addr.arpa
and 48 more
/10 is not on a 8-bit boundary, so it takes 64 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address10010110.01000000.00000000.00000000150.64.0.0
Subnet mask11111111.11000000.00000000.00000000255.192.0.0
Network10010110.01000000.00000000.00000000150.64.0.0
Broadcast10010110.01111111.11111111.11111111150.127.255.255
Split into smaller subnets/17
/11 (2)/12 (4)/13 (8)/14 (16)/15 (32)/16 (64)/17 (128)/18 (256)/19 (512)/20 (1,024)/21 (2,048)/22 (4,096)

150.64.0.0/10 makes 128 subnets of /17.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1150.64.0.0/17150.64.0.1 to 150.64.127.254150.64.127.25532,766
2150.64.128.0/17150.64.128.1 to 150.64.255.254150.64.255.25532,766
3150.65.0.0/17150.65.0.1 to 150.65.127.254150.65.127.25532,766
4150.65.128.0/17150.65.128.1 to 150.65.255.254150.65.255.25532,766
5150.66.0.0/17150.66.0.1 to 150.66.127.254150.66.127.25532,766
6150.66.128.0/17150.66.128.1 to 150.66.255.254150.66.255.25532,766
7150.67.0.0/17150.67.0.1 to 150.67.127.254150.67.127.25532,766
8150.67.128.0/17150.67.128.1 to 150.67.255.254150.67.255.25532,766
9150.68.0.0/17150.68.0.1 to 150.68.127.254150.68.127.25532,766
10150.68.128.0/17150.68.128.1 to 150.68.255.254150.68.255.25532,766
11150.69.0.0/17150.69.0.1 to 150.69.127.254150.69.127.25532,766
12150.69.128.0/17150.69.128.1 to 150.69.255.254150.69.255.25532,766
13150.70.0.0/17150.70.0.1 to 150.70.127.254150.70.127.25532,766
14150.70.128.0/17150.70.128.1 to 150.70.255.254150.70.255.25532,766
15150.71.0.0/17150.71.0.1 to 150.71.127.254150.71.127.25532,766
16150.71.128.0/17150.71.128.1 to 150.71.255.254150.71.255.25532,766
17150.72.0.0/17150.72.0.1 to 150.72.127.254150.72.127.25532,766
18150.72.128.0/17150.72.128.1 to 150.72.255.254150.72.255.25532,766
19150.73.0.0/17150.73.0.1 to 150.73.127.254150.73.127.25532,766
20150.73.128.0/17150.73.128.1 to 150.73.255.254150.73.255.25532,766
21150.74.0.0/17150.74.0.1 to 150.74.127.254150.74.127.25532,766
22150.74.128.0/17150.74.128.1 to 150.74.255.254150.74.255.25532,766
23150.75.0.0/17150.75.0.1 to 150.75.127.254150.75.127.25532,766
24150.75.128.0/17150.75.128.1 to 150.75.255.254150.75.255.25532,766
25150.76.0.0/17150.76.0.1 to 150.76.127.254150.76.127.25532,766
26150.76.128.0/17150.76.128.1 to 150.76.255.254150.76.255.25532,766
27150.77.0.0/17150.77.0.1 to 150.77.127.254150.77.127.25532,766
28150.77.128.0/17150.77.128.1 to 150.77.255.254150.77.255.25532,766
29150.78.0.0/17150.78.0.1 to 150.78.127.254150.78.127.25532,766
30150.78.128.0/17150.78.128.1 to 150.78.255.254150.78.255.25532,766
31150.79.0.0/17150.79.0.1 to 150.79.127.254150.79.127.25532,766
32150.79.128.0/17150.79.128.1 to 150.79.255.254150.79.255.25532,766
33150.80.0.0/17150.80.0.1 to 150.80.127.254150.80.127.25532,766
34150.80.128.0/17150.80.128.1 to 150.80.255.254150.80.255.25532,766
35150.81.0.0/17150.81.0.1 to 150.81.127.254150.81.127.25532,766
36150.81.128.0/17150.81.128.1 to 150.81.255.254150.81.255.25532,766
37150.82.0.0/17150.82.0.1 to 150.82.127.254150.82.127.25532,766
38150.82.128.0/17150.82.128.1 to 150.82.255.254150.82.255.25532,766
39150.83.0.0/17150.83.0.1 to 150.83.127.254150.83.127.25532,766
40150.83.128.0/17150.83.128.1 to 150.83.255.254150.83.255.25532,766
41150.84.0.0/17150.84.0.1 to 150.84.127.254150.84.127.25532,766
42150.84.128.0/17150.84.128.1 to 150.84.255.254150.84.255.25532,766
43150.85.0.0/17150.85.0.1 to 150.85.127.254150.85.127.25532,766
44150.85.128.0/17150.85.128.1 to 150.85.255.254150.85.255.25532,766
45150.86.0.0/17150.86.0.1 to 150.86.127.254150.86.127.25532,766
46150.86.128.0/17150.86.128.1 to 150.86.255.254150.86.255.25532,766
47150.87.0.0/17150.87.0.1 to 150.87.127.254150.87.127.25532,766
48150.87.128.0/17150.87.128.1 to 150.87.255.254150.87.255.25532,766
49150.88.0.0/17150.88.0.1 to 150.88.127.254150.88.127.25532,766
50150.88.128.0/17150.88.128.1 to 150.88.255.254150.88.255.25532,766
51150.89.0.0/17150.89.0.1 to 150.89.127.254150.89.127.25532,766
52150.89.128.0/17150.89.128.1 to 150.89.255.254150.89.255.25532,766
53150.90.0.0/17150.90.0.1 to 150.90.127.254150.90.127.25532,766
54150.90.128.0/17150.90.128.1 to 150.90.255.254150.90.255.25532,766
55150.91.0.0/17150.91.0.1 to 150.91.127.254150.91.127.25532,766
56150.91.128.0/17150.91.128.1 to 150.91.255.254150.91.255.25532,766
57150.92.0.0/17150.92.0.1 to 150.92.127.254150.92.127.25532,766
58150.92.128.0/17150.92.128.1 to 150.92.255.254150.92.255.25532,766
59150.93.0.0/17150.93.0.1 to 150.93.127.254150.93.127.25532,766
60150.93.128.0/17150.93.128.1 to 150.93.255.254150.93.255.25532,766
61150.94.0.0/17150.94.0.1 to 150.94.127.254150.94.127.25532,766
62150.94.128.0/17150.94.128.1 to 150.94.255.254150.94.255.25532,766
63150.95.0.0/17150.95.0.1 to 150.95.127.254150.95.127.25532,766
64150.95.128.0/17150.95.128.1 to 150.95.255.254150.95.255.25532,766
65150.96.0.0/17150.96.0.1 to 150.96.127.254150.96.127.25532,766
66150.96.128.0/17150.96.128.1 to 150.96.255.254150.96.255.25532,766
67150.97.0.0/17150.97.0.1 to 150.97.127.254150.97.127.25532,766
68150.97.128.0/17150.97.128.1 to 150.97.255.254150.97.255.25532,766
69150.98.0.0/17150.98.0.1 to 150.98.127.254150.98.127.25532,766
70150.98.128.0/17150.98.128.1 to 150.98.255.254150.98.255.25532,766
71150.99.0.0/17150.99.0.1 to 150.99.127.254150.99.127.25532,766
72150.99.128.0/17150.99.128.1 to 150.99.255.254150.99.255.25532,766
73150.100.0.0/17150.100.0.1 to 150.100.127.254150.100.127.25532,766
74150.100.128.0/17150.100.128.1 to 150.100.255.254150.100.255.25532,766
75150.101.0.0/17150.101.0.1 to 150.101.127.254150.101.127.25532,766
76150.101.128.0/17150.101.128.1 to 150.101.255.254150.101.255.25532,766
77150.102.0.0/17150.102.0.1 to 150.102.127.254150.102.127.25532,766
78150.102.128.0/17150.102.128.1 to 150.102.255.254150.102.255.25532,766
79150.103.0.0/17150.103.0.1 to 150.103.127.254150.103.127.25532,766
80150.103.128.0/17150.103.128.1 to 150.103.255.254150.103.255.25532,766
81150.104.0.0/17150.104.0.1 to 150.104.127.254150.104.127.25532,766
82150.104.128.0/17150.104.128.1 to 150.104.255.254150.104.255.25532,766
83150.105.0.0/17150.105.0.1 to 150.105.127.254150.105.127.25532,766
84150.105.128.0/17150.105.128.1 to 150.105.255.254150.105.255.25532,766
85150.106.0.0/17150.106.0.1 to 150.106.127.254150.106.127.25532,766
86150.106.128.0/17150.106.128.1 to 150.106.255.254150.106.255.25532,766
87150.107.0.0/17150.107.0.1 to 150.107.127.254150.107.127.25532,766
88150.107.128.0/17150.107.128.1 to 150.107.255.254150.107.255.25532,766
89150.108.0.0/17150.108.0.1 to 150.108.127.254150.108.127.25532,766
90150.108.128.0/17150.108.128.1 to 150.108.255.254150.108.255.25532,766
91150.109.0.0/17150.109.0.1 to 150.109.127.254150.109.127.25532,766
92150.109.128.0/17150.109.128.1 to 150.109.255.254150.109.255.25532,766
93150.110.0.0/17150.110.0.1 to 150.110.127.254150.110.127.25532,766
94150.110.128.0/17150.110.128.1 to 150.110.255.254150.110.255.25532,766
95150.111.0.0/17150.111.0.1 to 150.111.127.254150.111.127.25532,766
96150.111.128.0/17150.111.128.1 to 150.111.255.254150.111.255.25532,766
97150.112.0.0/17150.112.0.1 to 150.112.127.254150.112.127.25532,766
98150.112.128.0/17150.112.128.1 to 150.112.255.254150.112.255.25532,766
99150.113.0.0/17150.113.0.1 to 150.113.127.254150.113.127.25532,766
100150.113.128.0/17150.113.128.1 to 150.113.255.254150.113.255.25532,766
101150.114.0.0/17150.114.0.1 to 150.114.127.254150.114.127.25532,766
102150.114.128.0/17150.114.128.1 to 150.114.255.254150.114.255.25532,766
103150.115.0.0/17150.115.0.1 to 150.115.127.254150.115.127.25532,766
104150.115.128.0/17150.115.128.1 to 150.115.255.254150.115.255.25532,766
105150.116.0.0/17150.116.0.1 to 150.116.127.254150.116.127.25532,766
106150.116.128.0/17150.116.128.1 to 150.116.255.254150.116.255.25532,766
107150.117.0.0/17150.117.0.1 to 150.117.127.254150.117.127.25532,766
108150.117.128.0/17150.117.128.1 to 150.117.255.254150.117.255.25532,766
109150.118.0.0/17150.118.0.1 to 150.118.127.254150.118.127.25532,766
110150.118.128.0/17150.118.128.1 to 150.118.255.254150.118.255.25532,766
111150.119.0.0/17150.119.0.1 to 150.119.127.254150.119.127.25532,766
112150.119.128.0/17150.119.128.1 to 150.119.255.254150.119.255.25532,766
113150.120.0.0/17150.120.0.1 to 150.120.127.254150.120.127.25532,766
114150.120.128.0/17150.120.128.1 to 150.120.255.254150.120.255.25532,766
115150.121.0.0/17150.121.0.1 to 150.121.127.254150.121.127.25532,766
116150.121.128.0/17150.121.128.1 to 150.121.255.254150.121.255.25532,766
117150.122.0.0/17150.122.0.1 to 150.122.127.254150.122.127.25532,766
118150.122.128.0/17150.122.128.1 to 150.122.255.254150.122.255.25532,766
119150.123.0.0/17150.123.0.1 to 150.123.127.254150.123.127.25532,766
120150.123.128.0/17150.123.128.1 to 150.123.255.254150.123.255.25532,766
121150.124.0.0/17150.124.0.1 to 150.124.127.254150.124.127.25532,766
122150.124.128.0/17150.124.128.1 to 150.124.255.254150.124.255.25532,766
123150.125.0.0/17150.125.0.1 to 150.125.127.254150.125.127.25532,766
124150.125.128.0/17150.125.128.1 to 150.125.255.254150.125.255.25532,766
125150.126.0.0/17150.126.0.1 to 150.126.127.254150.126.127.25532,766
126150.126.128.0/17150.126.128.1 to 150.126.255.254150.126.255.25532,766
127150.127.0.0/17150.127.0.1 to 150.127.127.254150.127.127.25532,766
128150.127.128.0/17150.127.128.1 to 150.127.255.254150.127.255.25532,766

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.