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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.

Network152.92.0.0/15
Usable hosts131,070
Subnet mask255.254.0.0
Addresses131,072
Network address
152.92.0.0
Broadcast address
152.93.255.255
First usable
152.92.0.1
Last usable
152.93.255.254
Usable hosts
131,070 (131,072 less the network and broadcast addresses)
Subnet mask
255.254.0.0
Wildcard mask
0.1.255.255 (Cisco ACLs, OSPF)
Prefix length
/15
Type
Public public
Old class
B (default /16)
As numbers
Hex 985C0000 · Integer 2556166144 to 2556297215
Reverse DNS zones
92.152.in-addr.arpa
93.152.in-addr.arpa
/15 is not on a 8-bit boundary, so it takes 2 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address10011000.01011100.00000000.00000000152.92.0.0
Subnet mask11111111.11111110.00000000.00000000255.254.0.0
Network10011000.01011100.00000000.00000000152.92.0.0
Broadcast10011000.01011101.11111111.11111111152.93.255.255
Split into smaller subnets/22
/16 (2)/17 (4)/18 (8)/19 (16)/20 (32)/21 (64)/22 (128)/23 (256)/24 (512)/25 (1,024)/26 (2,048)/27 (4,096)

152.92.0.0/15 makes 128 subnets of /22.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1152.92.0.0/22152.92.0.1 to 152.92.3.254152.92.3.2551,022
2152.92.4.0/22152.92.4.1 to 152.92.7.254152.92.7.2551,022
3152.92.8.0/22152.92.8.1 to 152.92.11.254152.92.11.2551,022
4152.92.12.0/22152.92.12.1 to 152.92.15.254152.92.15.2551,022
5152.92.16.0/22152.92.16.1 to 152.92.19.254152.92.19.2551,022
6152.92.20.0/22152.92.20.1 to 152.92.23.254152.92.23.2551,022
7152.92.24.0/22152.92.24.1 to 152.92.27.254152.92.27.2551,022
8152.92.28.0/22152.92.28.1 to 152.92.31.254152.92.31.2551,022
9152.92.32.0/22152.92.32.1 to 152.92.35.254152.92.35.2551,022
10152.92.36.0/22152.92.36.1 to 152.92.39.254152.92.39.2551,022
11152.92.40.0/22152.92.40.1 to 152.92.43.254152.92.43.2551,022
12152.92.44.0/22152.92.44.1 to 152.92.47.254152.92.47.2551,022
13152.92.48.0/22152.92.48.1 to 152.92.51.254152.92.51.2551,022
14152.92.52.0/22152.92.52.1 to 152.92.55.254152.92.55.2551,022
15152.92.56.0/22152.92.56.1 to 152.92.59.254152.92.59.2551,022
16152.92.60.0/22152.92.60.1 to 152.92.63.254152.92.63.2551,022
17152.92.64.0/22152.92.64.1 to 152.92.67.254152.92.67.2551,022
18152.92.68.0/22152.92.68.1 to 152.92.71.254152.92.71.2551,022
19152.92.72.0/22152.92.72.1 to 152.92.75.254152.92.75.2551,022
20152.92.76.0/22152.92.76.1 to 152.92.79.254152.92.79.2551,022
21152.92.80.0/22152.92.80.1 to 152.92.83.254152.92.83.2551,022
22152.92.84.0/22152.92.84.1 to 152.92.87.254152.92.87.2551,022
23152.92.88.0/22152.92.88.1 to 152.92.91.254152.92.91.2551,022
24152.92.92.0/22152.92.92.1 to 152.92.95.254152.92.95.2551,022
25152.92.96.0/22152.92.96.1 to 152.92.99.254152.92.99.2551,022
26152.92.100.0/22152.92.100.1 to 152.92.103.254152.92.103.2551,022
27152.92.104.0/22152.92.104.1 to 152.92.107.254152.92.107.2551,022
28152.92.108.0/22152.92.108.1 to 152.92.111.254152.92.111.2551,022
29152.92.112.0/22152.92.112.1 to 152.92.115.254152.92.115.2551,022
30152.92.116.0/22152.92.116.1 to 152.92.119.254152.92.119.2551,022
31152.92.120.0/22152.92.120.1 to 152.92.123.254152.92.123.2551,022
32152.92.124.0/22152.92.124.1 to 152.92.127.254152.92.127.2551,022
33152.92.128.0/22152.92.128.1 to 152.92.131.254152.92.131.2551,022
34152.92.132.0/22152.92.132.1 to 152.92.135.254152.92.135.2551,022
35152.92.136.0/22152.92.136.1 to 152.92.139.254152.92.139.2551,022
36152.92.140.0/22152.92.140.1 to 152.92.143.254152.92.143.2551,022
37152.92.144.0/22152.92.144.1 to 152.92.147.254152.92.147.2551,022
38152.92.148.0/22152.92.148.1 to 152.92.151.254152.92.151.2551,022
39152.92.152.0/22152.92.152.1 to 152.92.155.254152.92.155.2551,022
40152.92.156.0/22152.92.156.1 to 152.92.159.254152.92.159.2551,022
41152.92.160.0/22152.92.160.1 to 152.92.163.254152.92.163.2551,022
42152.92.164.0/22152.92.164.1 to 152.92.167.254152.92.167.2551,022
43152.92.168.0/22152.92.168.1 to 152.92.171.254152.92.171.2551,022
44152.92.172.0/22152.92.172.1 to 152.92.175.254152.92.175.2551,022
45152.92.176.0/22152.92.176.1 to 152.92.179.254152.92.179.2551,022
46152.92.180.0/22152.92.180.1 to 152.92.183.254152.92.183.2551,022
47152.92.184.0/22152.92.184.1 to 152.92.187.254152.92.187.2551,022
48152.92.188.0/22152.92.188.1 to 152.92.191.254152.92.191.2551,022
49152.92.192.0/22152.92.192.1 to 152.92.195.254152.92.195.2551,022
50152.92.196.0/22152.92.196.1 to 152.92.199.254152.92.199.2551,022
51152.92.200.0/22152.92.200.1 to 152.92.203.254152.92.203.2551,022
52152.92.204.0/22152.92.204.1 to 152.92.207.254152.92.207.2551,022
53152.92.208.0/22152.92.208.1 to 152.92.211.254152.92.211.2551,022
54152.92.212.0/22152.92.212.1 to 152.92.215.254152.92.215.2551,022
55152.92.216.0/22152.92.216.1 to 152.92.219.254152.92.219.2551,022
56152.92.220.0/22152.92.220.1 to 152.92.223.254152.92.223.2551,022
57152.92.224.0/22152.92.224.1 to 152.92.227.254152.92.227.2551,022
58152.92.228.0/22152.92.228.1 to 152.92.231.254152.92.231.2551,022
59152.92.232.0/22152.92.232.1 to 152.92.235.254152.92.235.2551,022
60152.92.236.0/22152.92.236.1 to 152.92.239.254152.92.239.2551,022
61152.92.240.0/22152.92.240.1 to 152.92.243.254152.92.243.2551,022
62152.92.244.0/22152.92.244.1 to 152.92.247.254152.92.247.2551,022
63152.92.248.0/22152.92.248.1 to 152.92.251.254152.92.251.2551,022
64152.92.252.0/22152.92.252.1 to 152.92.255.254152.92.255.2551,022
65152.93.0.0/22152.93.0.1 to 152.93.3.254152.93.3.2551,022
66152.93.4.0/22152.93.4.1 to 152.93.7.254152.93.7.2551,022
67152.93.8.0/22152.93.8.1 to 152.93.11.254152.93.11.2551,022
68152.93.12.0/22152.93.12.1 to 152.93.15.254152.93.15.2551,022
69152.93.16.0/22152.93.16.1 to 152.93.19.254152.93.19.2551,022
70152.93.20.0/22152.93.20.1 to 152.93.23.254152.93.23.2551,022
71152.93.24.0/22152.93.24.1 to 152.93.27.254152.93.27.2551,022
72152.93.28.0/22152.93.28.1 to 152.93.31.254152.93.31.2551,022
73152.93.32.0/22152.93.32.1 to 152.93.35.254152.93.35.2551,022
74152.93.36.0/22152.93.36.1 to 152.93.39.254152.93.39.2551,022
75152.93.40.0/22152.93.40.1 to 152.93.43.254152.93.43.2551,022
76152.93.44.0/22152.93.44.1 to 152.93.47.254152.93.47.2551,022
77152.93.48.0/22152.93.48.1 to 152.93.51.254152.93.51.2551,022
78152.93.52.0/22152.93.52.1 to 152.93.55.254152.93.55.2551,022
79152.93.56.0/22152.93.56.1 to 152.93.59.254152.93.59.2551,022
80152.93.60.0/22152.93.60.1 to 152.93.63.254152.93.63.2551,022
81152.93.64.0/22152.93.64.1 to 152.93.67.254152.93.67.2551,022
82152.93.68.0/22152.93.68.1 to 152.93.71.254152.93.71.2551,022
83152.93.72.0/22152.93.72.1 to 152.93.75.254152.93.75.2551,022
84152.93.76.0/22152.93.76.1 to 152.93.79.254152.93.79.2551,022
85152.93.80.0/22152.93.80.1 to 152.93.83.254152.93.83.2551,022
86152.93.84.0/22152.93.84.1 to 152.93.87.254152.93.87.2551,022
87152.93.88.0/22152.93.88.1 to 152.93.91.254152.93.91.2551,022
88152.93.92.0/22152.93.92.1 to 152.93.95.254152.93.95.2551,022
89152.93.96.0/22152.93.96.1 to 152.93.99.254152.93.99.2551,022
90152.93.100.0/22152.93.100.1 to 152.93.103.254152.93.103.2551,022
91152.93.104.0/22152.93.104.1 to 152.93.107.254152.93.107.2551,022
92152.93.108.0/22152.93.108.1 to 152.93.111.254152.93.111.2551,022
93152.93.112.0/22152.93.112.1 to 152.93.115.254152.93.115.2551,022
94152.93.116.0/22152.93.116.1 to 152.93.119.254152.93.119.2551,022
95152.93.120.0/22152.93.120.1 to 152.93.123.254152.93.123.2551,022
96152.93.124.0/22152.93.124.1 to 152.93.127.254152.93.127.2551,022
97152.93.128.0/22152.93.128.1 to 152.93.131.254152.93.131.2551,022
98152.93.132.0/22152.93.132.1 to 152.93.135.254152.93.135.2551,022
99152.93.136.0/22152.93.136.1 to 152.93.139.254152.93.139.2551,022
100152.93.140.0/22152.93.140.1 to 152.93.143.254152.93.143.2551,022
101152.93.144.0/22152.93.144.1 to 152.93.147.254152.93.147.2551,022
102152.93.148.0/22152.93.148.1 to 152.93.151.254152.93.151.2551,022
103152.93.152.0/22152.93.152.1 to 152.93.155.254152.93.155.2551,022
104152.93.156.0/22152.93.156.1 to 152.93.159.254152.93.159.2551,022
105152.93.160.0/22152.93.160.1 to 152.93.163.254152.93.163.2551,022
106152.93.164.0/22152.93.164.1 to 152.93.167.254152.93.167.2551,022
107152.93.168.0/22152.93.168.1 to 152.93.171.254152.93.171.2551,022
108152.93.172.0/22152.93.172.1 to 152.93.175.254152.93.175.2551,022
109152.93.176.0/22152.93.176.1 to 152.93.179.254152.93.179.2551,022
110152.93.180.0/22152.93.180.1 to 152.93.183.254152.93.183.2551,022
111152.93.184.0/22152.93.184.1 to 152.93.187.254152.93.187.2551,022
112152.93.188.0/22152.93.188.1 to 152.93.191.254152.93.191.2551,022
113152.93.192.0/22152.93.192.1 to 152.93.195.254152.93.195.2551,022
114152.93.196.0/22152.93.196.1 to 152.93.199.254152.93.199.2551,022
115152.93.200.0/22152.93.200.1 to 152.93.203.254152.93.203.2551,022
116152.93.204.0/22152.93.204.1 to 152.93.207.254152.93.207.2551,022
117152.93.208.0/22152.93.208.1 to 152.93.211.254152.93.211.2551,022
118152.93.212.0/22152.93.212.1 to 152.93.215.254152.93.215.2551,022
119152.93.216.0/22152.93.216.1 to 152.93.219.254152.93.219.2551,022
120152.93.220.0/22152.93.220.1 to 152.93.223.254152.93.223.2551,022
121152.93.224.0/22152.93.224.1 to 152.93.227.254152.93.227.2551,022
122152.93.228.0/22152.93.228.1 to 152.93.231.254152.93.231.2551,022
123152.93.232.0/22152.93.232.1 to 152.93.235.254152.93.235.2551,022
124152.93.236.0/22152.93.236.1 to 152.93.239.254152.93.239.2551,022
125152.93.240.0/22152.93.240.1 to 152.93.243.254152.93.243.2551,022
126152.93.244.0/22152.93.244.1 to 152.93.247.254152.93.247.2551,022
127152.93.248.0/22152.93.248.1 to 152.93.251.254152.93.251.2551,022
128152.93.252.0/22152.93.252.1 to 152.93.255.254152.93.255.2551,022

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.