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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.

Network174.232.0.0/15
Usable hosts131,070
Subnet mask255.254.0.0
Addresses131,072
Network address
174.232.0.0
Broadcast address
174.233.255.255
First usable
174.232.0.1
Last usable
174.233.255.254
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 AEE80000 · Integer 2934439936 to 2934571007
Reverse DNS zones
232.174.in-addr.arpa
233.174.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
Address10101110.11101000.00000000.00000000174.232.0.0
Subnet mask11111111.11111110.00000000.00000000255.254.0.0
Network10101110.11101000.00000000.00000000174.232.0.0
Broadcast10101110.11101001.11111111.11111111174.233.255.255
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)

174.232.0.0/15 makes 128 subnets of /22.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1174.232.0.0/22174.232.0.1 to 174.232.3.254174.232.3.2551,022
2174.232.4.0/22174.232.4.1 to 174.232.7.254174.232.7.2551,022
3174.232.8.0/22174.232.8.1 to 174.232.11.254174.232.11.2551,022
4174.232.12.0/22174.232.12.1 to 174.232.15.254174.232.15.2551,022
5174.232.16.0/22174.232.16.1 to 174.232.19.254174.232.19.2551,022
6174.232.20.0/22174.232.20.1 to 174.232.23.254174.232.23.2551,022
7174.232.24.0/22174.232.24.1 to 174.232.27.254174.232.27.2551,022
8174.232.28.0/22174.232.28.1 to 174.232.31.254174.232.31.2551,022
9174.232.32.0/22174.232.32.1 to 174.232.35.254174.232.35.2551,022
10174.232.36.0/22174.232.36.1 to 174.232.39.254174.232.39.2551,022
11174.232.40.0/22174.232.40.1 to 174.232.43.254174.232.43.2551,022
12174.232.44.0/22174.232.44.1 to 174.232.47.254174.232.47.2551,022
13174.232.48.0/22174.232.48.1 to 174.232.51.254174.232.51.2551,022
14174.232.52.0/22174.232.52.1 to 174.232.55.254174.232.55.2551,022
15174.232.56.0/22174.232.56.1 to 174.232.59.254174.232.59.2551,022
16174.232.60.0/22174.232.60.1 to 174.232.63.254174.232.63.2551,022
17174.232.64.0/22174.232.64.1 to 174.232.67.254174.232.67.2551,022
18174.232.68.0/22174.232.68.1 to 174.232.71.254174.232.71.2551,022
19174.232.72.0/22174.232.72.1 to 174.232.75.254174.232.75.2551,022
20174.232.76.0/22174.232.76.1 to 174.232.79.254174.232.79.2551,022
21174.232.80.0/22174.232.80.1 to 174.232.83.254174.232.83.2551,022
22174.232.84.0/22174.232.84.1 to 174.232.87.254174.232.87.2551,022
23174.232.88.0/22174.232.88.1 to 174.232.91.254174.232.91.2551,022
24174.232.92.0/22174.232.92.1 to 174.232.95.254174.232.95.2551,022
25174.232.96.0/22174.232.96.1 to 174.232.99.254174.232.99.2551,022
26174.232.100.0/22174.232.100.1 to 174.232.103.254174.232.103.2551,022
27174.232.104.0/22174.232.104.1 to 174.232.107.254174.232.107.2551,022
28174.232.108.0/22174.232.108.1 to 174.232.111.254174.232.111.2551,022
29174.232.112.0/22174.232.112.1 to 174.232.115.254174.232.115.2551,022
30174.232.116.0/22174.232.116.1 to 174.232.119.254174.232.119.2551,022
31174.232.120.0/22174.232.120.1 to 174.232.123.254174.232.123.2551,022
32174.232.124.0/22174.232.124.1 to 174.232.127.254174.232.127.2551,022
33174.232.128.0/22174.232.128.1 to 174.232.131.254174.232.131.2551,022
34174.232.132.0/22174.232.132.1 to 174.232.135.254174.232.135.2551,022
35174.232.136.0/22174.232.136.1 to 174.232.139.254174.232.139.2551,022
36174.232.140.0/22174.232.140.1 to 174.232.143.254174.232.143.2551,022
37174.232.144.0/22174.232.144.1 to 174.232.147.254174.232.147.2551,022
38174.232.148.0/22174.232.148.1 to 174.232.151.254174.232.151.2551,022
39174.232.152.0/22174.232.152.1 to 174.232.155.254174.232.155.2551,022
40174.232.156.0/22174.232.156.1 to 174.232.159.254174.232.159.2551,022
41174.232.160.0/22174.232.160.1 to 174.232.163.254174.232.163.2551,022
42174.232.164.0/22174.232.164.1 to 174.232.167.254174.232.167.2551,022
43174.232.168.0/22174.232.168.1 to 174.232.171.254174.232.171.2551,022
44174.232.172.0/22174.232.172.1 to 174.232.175.254174.232.175.2551,022
45174.232.176.0/22174.232.176.1 to 174.232.179.254174.232.179.2551,022
46174.232.180.0/22174.232.180.1 to 174.232.183.254174.232.183.2551,022
47174.232.184.0/22174.232.184.1 to 174.232.187.254174.232.187.2551,022
48174.232.188.0/22174.232.188.1 to 174.232.191.254174.232.191.2551,022
49174.232.192.0/22174.232.192.1 to 174.232.195.254174.232.195.2551,022
50174.232.196.0/22174.232.196.1 to 174.232.199.254174.232.199.2551,022
51174.232.200.0/22174.232.200.1 to 174.232.203.254174.232.203.2551,022
52174.232.204.0/22174.232.204.1 to 174.232.207.254174.232.207.2551,022
53174.232.208.0/22174.232.208.1 to 174.232.211.254174.232.211.2551,022
54174.232.212.0/22174.232.212.1 to 174.232.215.254174.232.215.2551,022
55174.232.216.0/22174.232.216.1 to 174.232.219.254174.232.219.2551,022
56174.232.220.0/22174.232.220.1 to 174.232.223.254174.232.223.2551,022
57174.232.224.0/22174.232.224.1 to 174.232.227.254174.232.227.2551,022
58174.232.228.0/22174.232.228.1 to 174.232.231.254174.232.231.2551,022
59174.232.232.0/22174.232.232.1 to 174.232.235.254174.232.235.2551,022
60174.232.236.0/22174.232.236.1 to 174.232.239.254174.232.239.2551,022
61174.232.240.0/22174.232.240.1 to 174.232.243.254174.232.243.2551,022
62174.232.244.0/22174.232.244.1 to 174.232.247.254174.232.247.2551,022
63174.232.248.0/22174.232.248.1 to 174.232.251.254174.232.251.2551,022
64174.232.252.0/22174.232.252.1 to 174.232.255.254174.232.255.2551,022
65174.233.0.0/22174.233.0.1 to 174.233.3.254174.233.3.2551,022
66174.233.4.0/22174.233.4.1 to 174.233.7.254174.233.7.2551,022
67174.233.8.0/22174.233.8.1 to 174.233.11.254174.233.11.2551,022
68174.233.12.0/22174.233.12.1 to 174.233.15.254174.233.15.2551,022
69174.233.16.0/22174.233.16.1 to 174.233.19.254174.233.19.2551,022
70174.233.20.0/22174.233.20.1 to 174.233.23.254174.233.23.2551,022
71174.233.24.0/22174.233.24.1 to 174.233.27.254174.233.27.2551,022
72174.233.28.0/22174.233.28.1 to 174.233.31.254174.233.31.2551,022
73174.233.32.0/22174.233.32.1 to 174.233.35.254174.233.35.2551,022
74174.233.36.0/22174.233.36.1 to 174.233.39.254174.233.39.2551,022
75174.233.40.0/22174.233.40.1 to 174.233.43.254174.233.43.2551,022
76174.233.44.0/22174.233.44.1 to 174.233.47.254174.233.47.2551,022
77174.233.48.0/22174.233.48.1 to 174.233.51.254174.233.51.2551,022
78174.233.52.0/22174.233.52.1 to 174.233.55.254174.233.55.2551,022
79174.233.56.0/22174.233.56.1 to 174.233.59.254174.233.59.2551,022
80174.233.60.0/22174.233.60.1 to 174.233.63.254174.233.63.2551,022
81174.233.64.0/22174.233.64.1 to 174.233.67.254174.233.67.2551,022
82174.233.68.0/22174.233.68.1 to 174.233.71.254174.233.71.2551,022
83174.233.72.0/22174.233.72.1 to 174.233.75.254174.233.75.2551,022
84174.233.76.0/22174.233.76.1 to 174.233.79.254174.233.79.2551,022
85174.233.80.0/22174.233.80.1 to 174.233.83.254174.233.83.2551,022
86174.233.84.0/22174.233.84.1 to 174.233.87.254174.233.87.2551,022
87174.233.88.0/22174.233.88.1 to 174.233.91.254174.233.91.2551,022
88174.233.92.0/22174.233.92.1 to 174.233.95.254174.233.95.2551,022
89174.233.96.0/22174.233.96.1 to 174.233.99.254174.233.99.2551,022
90174.233.100.0/22174.233.100.1 to 174.233.103.254174.233.103.2551,022
91174.233.104.0/22174.233.104.1 to 174.233.107.254174.233.107.2551,022
92174.233.108.0/22174.233.108.1 to 174.233.111.254174.233.111.2551,022
93174.233.112.0/22174.233.112.1 to 174.233.115.254174.233.115.2551,022
94174.233.116.0/22174.233.116.1 to 174.233.119.254174.233.119.2551,022
95174.233.120.0/22174.233.120.1 to 174.233.123.254174.233.123.2551,022
96174.233.124.0/22174.233.124.1 to 174.233.127.254174.233.127.2551,022
97174.233.128.0/22174.233.128.1 to 174.233.131.254174.233.131.2551,022
98174.233.132.0/22174.233.132.1 to 174.233.135.254174.233.135.2551,022
99174.233.136.0/22174.233.136.1 to 174.233.139.254174.233.139.2551,022
100174.233.140.0/22174.233.140.1 to 174.233.143.254174.233.143.2551,022
101174.233.144.0/22174.233.144.1 to 174.233.147.254174.233.147.2551,022
102174.233.148.0/22174.233.148.1 to 174.233.151.254174.233.151.2551,022
103174.233.152.0/22174.233.152.1 to 174.233.155.254174.233.155.2551,022
104174.233.156.0/22174.233.156.1 to 174.233.159.254174.233.159.2551,022
105174.233.160.0/22174.233.160.1 to 174.233.163.254174.233.163.2551,022
106174.233.164.0/22174.233.164.1 to 174.233.167.254174.233.167.2551,022
107174.233.168.0/22174.233.168.1 to 174.233.171.254174.233.171.2551,022
108174.233.172.0/22174.233.172.1 to 174.233.175.254174.233.175.2551,022
109174.233.176.0/22174.233.176.1 to 174.233.179.254174.233.179.2551,022
110174.233.180.0/22174.233.180.1 to 174.233.183.254174.233.183.2551,022
111174.233.184.0/22174.233.184.1 to 174.233.187.254174.233.187.2551,022
112174.233.188.0/22174.233.188.1 to 174.233.191.254174.233.191.2551,022
113174.233.192.0/22174.233.192.1 to 174.233.195.254174.233.195.2551,022
114174.233.196.0/22174.233.196.1 to 174.233.199.254174.233.199.2551,022
115174.233.200.0/22174.233.200.1 to 174.233.203.254174.233.203.2551,022
116174.233.204.0/22174.233.204.1 to 174.233.207.254174.233.207.2551,022
117174.233.208.0/22174.233.208.1 to 174.233.211.254174.233.211.2551,022
118174.233.212.0/22174.233.212.1 to 174.233.215.254174.233.215.2551,022
119174.233.216.0/22174.233.216.1 to 174.233.219.254174.233.219.2551,022
120174.233.220.0/22174.233.220.1 to 174.233.223.254174.233.223.2551,022
121174.233.224.0/22174.233.224.1 to 174.233.227.254174.233.227.2551,022
122174.233.228.0/22174.233.228.1 to 174.233.231.254174.233.231.2551,022
123174.233.232.0/22174.233.232.1 to 174.233.235.254174.233.235.2551,022
124174.233.236.0/22174.233.236.1 to 174.233.239.254174.233.239.2551,022
125174.233.240.0/22174.233.240.1 to 174.233.243.254174.233.243.2551,022
126174.233.244.0/22174.233.244.1 to 174.233.247.254174.233.247.2551,022
127174.233.248.0/22174.233.248.1 to 174.233.251.254174.233.251.2551,022
128174.233.252.0/22174.233.252.1 to 174.233.255.254174.233.255.2551,022

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.