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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.

Network224.148.0.0/15
Usable hosts131,070
Subnet mask255.254.0.0
Addresses131,072
Network address
224.148.0.0
Broadcast address
224.149.255.255
First usable
224.148.0.1
Last usable
224.149.255.254
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
Multicast 224.0.0.0/4
One-to-many traffic, such as IPTV and routing protocols
Old class
D (multicast)
As numbers
Hex E0940000 · Integer 3767795712 to 3767926783
Reverse DNS zones
148.224.in-addr.arpa
149.224.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
Address11100000.10010100.00000000.00000000224.148.0.0
Subnet mask11111111.11111110.00000000.00000000255.254.0.0
Network11100000.10010100.00000000.00000000224.148.0.0
Broadcast11100000.10010101.11111111.11111111224.149.255.255
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)

224.148.0.0/15 makes 128 subnets of /22.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1224.148.0.0/22224.148.0.1 to 224.148.3.254224.148.3.2551,022
2224.148.4.0/22224.148.4.1 to 224.148.7.254224.148.7.2551,022
3224.148.8.0/22224.148.8.1 to 224.148.11.254224.148.11.2551,022
4224.148.12.0/22224.148.12.1 to 224.148.15.254224.148.15.2551,022
5224.148.16.0/22224.148.16.1 to 224.148.19.254224.148.19.2551,022
6224.148.20.0/22224.148.20.1 to 224.148.23.254224.148.23.2551,022
7224.148.24.0/22224.148.24.1 to 224.148.27.254224.148.27.2551,022
8224.148.28.0/22224.148.28.1 to 224.148.31.254224.148.31.2551,022
9224.148.32.0/22224.148.32.1 to 224.148.35.254224.148.35.2551,022
10224.148.36.0/22224.148.36.1 to 224.148.39.254224.148.39.2551,022
11224.148.40.0/22224.148.40.1 to 224.148.43.254224.148.43.2551,022
12224.148.44.0/22224.148.44.1 to 224.148.47.254224.148.47.2551,022
13224.148.48.0/22224.148.48.1 to 224.148.51.254224.148.51.2551,022
14224.148.52.0/22224.148.52.1 to 224.148.55.254224.148.55.2551,022
15224.148.56.0/22224.148.56.1 to 224.148.59.254224.148.59.2551,022
16224.148.60.0/22224.148.60.1 to 224.148.63.254224.148.63.2551,022
17224.148.64.0/22224.148.64.1 to 224.148.67.254224.148.67.2551,022
18224.148.68.0/22224.148.68.1 to 224.148.71.254224.148.71.2551,022
19224.148.72.0/22224.148.72.1 to 224.148.75.254224.148.75.2551,022
20224.148.76.0/22224.148.76.1 to 224.148.79.254224.148.79.2551,022
21224.148.80.0/22224.148.80.1 to 224.148.83.254224.148.83.2551,022
22224.148.84.0/22224.148.84.1 to 224.148.87.254224.148.87.2551,022
23224.148.88.0/22224.148.88.1 to 224.148.91.254224.148.91.2551,022
24224.148.92.0/22224.148.92.1 to 224.148.95.254224.148.95.2551,022
25224.148.96.0/22224.148.96.1 to 224.148.99.254224.148.99.2551,022
26224.148.100.0/22224.148.100.1 to 224.148.103.254224.148.103.2551,022
27224.148.104.0/22224.148.104.1 to 224.148.107.254224.148.107.2551,022
28224.148.108.0/22224.148.108.1 to 224.148.111.254224.148.111.2551,022
29224.148.112.0/22224.148.112.1 to 224.148.115.254224.148.115.2551,022
30224.148.116.0/22224.148.116.1 to 224.148.119.254224.148.119.2551,022
31224.148.120.0/22224.148.120.1 to 224.148.123.254224.148.123.2551,022
32224.148.124.0/22224.148.124.1 to 224.148.127.254224.148.127.2551,022
33224.148.128.0/22224.148.128.1 to 224.148.131.254224.148.131.2551,022
34224.148.132.0/22224.148.132.1 to 224.148.135.254224.148.135.2551,022
35224.148.136.0/22224.148.136.1 to 224.148.139.254224.148.139.2551,022
36224.148.140.0/22224.148.140.1 to 224.148.143.254224.148.143.2551,022
37224.148.144.0/22224.148.144.1 to 224.148.147.254224.148.147.2551,022
38224.148.148.0/22224.148.148.1 to 224.148.151.254224.148.151.2551,022
39224.148.152.0/22224.148.152.1 to 224.148.155.254224.148.155.2551,022
40224.148.156.0/22224.148.156.1 to 224.148.159.254224.148.159.2551,022
41224.148.160.0/22224.148.160.1 to 224.148.163.254224.148.163.2551,022
42224.148.164.0/22224.148.164.1 to 224.148.167.254224.148.167.2551,022
43224.148.168.0/22224.148.168.1 to 224.148.171.254224.148.171.2551,022
44224.148.172.0/22224.148.172.1 to 224.148.175.254224.148.175.2551,022
45224.148.176.0/22224.148.176.1 to 224.148.179.254224.148.179.2551,022
46224.148.180.0/22224.148.180.1 to 224.148.183.254224.148.183.2551,022
47224.148.184.0/22224.148.184.1 to 224.148.187.254224.148.187.2551,022
48224.148.188.0/22224.148.188.1 to 224.148.191.254224.148.191.2551,022
49224.148.192.0/22224.148.192.1 to 224.148.195.254224.148.195.2551,022
50224.148.196.0/22224.148.196.1 to 224.148.199.254224.148.199.2551,022
51224.148.200.0/22224.148.200.1 to 224.148.203.254224.148.203.2551,022
52224.148.204.0/22224.148.204.1 to 224.148.207.254224.148.207.2551,022
53224.148.208.0/22224.148.208.1 to 224.148.211.254224.148.211.2551,022
54224.148.212.0/22224.148.212.1 to 224.148.215.254224.148.215.2551,022
55224.148.216.0/22224.148.216.1 to 224.148.219.254224.148.219.2551,022
56224.148.220.0/22224.148.220.1 to 224.148.223.254224.148.223.2551,022
57224.148.224.0/22224.148.224.1 to 224.148.227.254224.148.227.2551,022
58224.148.228.0/22224.148.228.1 to 224.148.231.254224.148.231.2551,022
59224.148.232.0/22224.148.232.1 to 224.148.235.254224.148.235.2551,022
60224.148.236.0/22224.148.236.1 to 224.148.239.254224.148.239.2551,022
61224.148.240.0/22224.148.240.1 to 224.148.243.254224.148.243.2551,022
62224.148.244.0/22224.148.244.1 to 224.148.247.254224.148.247.2551,022
63224.148.248.0/22224.148.248.1 to 224.148.251.254224.148.251.2551,022
64224.148.252.0/22224.148.252.1 to 224.148.255.254224.148.255.2551,022
65224.149.0.0/22224.149.0.1 to 224.149.3.254224.149.3.2551,022
66224.149.4.0/22224.149.4.1 to 224.149.7.254224.149.7.2551,022
67224.149.8.0/22224.149.8.1 to 224.149.11.254224.149.11.2551,022
68224.149.12.0/22224.149.12.1 to 224.149.15.254224.149.15.2551,022
69224.149.16.0/22224.149.16.1 to 224.149.19.254224.149.19.2551,022
70224.149.20.0/22224.149.20.1 to 224.149.23.254224.149.23.2551,022
71224.149.24.0/22224.149.24.1 to 224.149.27.254224.149.27.2551,022
72224.149.28.0/22224.149.28.1 to 224.149.31.254224.149.31.2551,022
73224.149.32.0/22224.149.32.1 to 224.149.35.254224.149.35.2551,022
74224.149.36.0/22224.149.36.1 to 224.149.39.254224.149.39.2551,022
75224.149.40.0/22224.149.40.1 to 224.149.43.254224.149.43.2551,022
76224.149.44.0/22224.149.44.1 to 224.149.47.254224.149.47.2551,022
77224.149.48.0/22224.149.48.1 to 224.149.51.254224.149.51.2551,022
78224.149.52.0/22224.149.52.1 to 224.149.55.254224.149.55.2551,022
79224.149.56.0/22224.149.56.1 to 224.149.59.254224.149.59.2551,022
80224.149.60.0/22224.149.60.1 to 224.149.63.254224.149.63.2551,022
81224.149.64.0/22224.149.64.1 to 224.149.67.254224.149.67.2551,022
82224.149.68.0/22224.149.68.1 to 224.149.71.254224.149.71.2551,022
83224.149.72.0/22224.149.72.1 to 224.149.75.254224.149.75.2551,022
84224.149.76.0/22224.149.76.1 to 224.149.79.254224.149.79.2551,022
85224.149.80.0/22224.149.80.1 to 224.149.83.254224.149.83.2551,022
86224.149.84.0/22224.149.84.1 to 224.149.87.254224.149.87.2551,022
87224.149.88.0/22224.149.88.1 to 224.149.91.254224.149.91.2551,022
88224.149.92.0/22224.149.92.1 to 224.149.95.254224.149.95.2551,022
89224.149.96.0/22224.149.96.1 to 224.149.99.254224.149.99.2551,022
90224.149.100.0/22224.149.100.1 to 224.149.103.254224.149.103.2551,022
91224.149.104.0/22224.149.104.1 to 224.149.107.254224.149.107.2551,022
92224.149.108.0/22224.149.108.1 to 224.149.111.254224.149.111.2551,022
93224.149.112.0/22224.149.112.1 to 224.149.115.254224.149.115.2551,022
94224.149.116.0/22224.149.116.1 to 224.149.119.254224.149.119.2551,022
95224.149.120.0/22224.149.120.1 to 224.149.123.254224.149.123.2551,022
96224.149.124.0/22224.149.124.1 to 224.149.127.254224.149.127.2551,022
97224.149.128.0/22224.149.128.1 to 224.149.131.254224.149.131.2551,022
98224.149.132.0/22224.149.132.1 to 224.149.135.254224.149.135.2551,022
99224.149.136.0/22224.149.136.1 to 224.149.139.254224.149.139.2551,022
100224.149.140.0/22224.149.140.1 to 224.149.143.254224.149.143.2551,022
101224.149.144.0/22224.149.144.1 to 224.149.147.254224.149.147.2551,022
102224.149.148.0/22224.149.148.1 to 224.149.151.254224.149.151.2551,022
103224.149.152.0/22224.149.152.1 to 224.149.155.254224.149.155.2551,022
104224.149.156.0/22224.149.156.1 to 224.149.159.254224.149.159.2551,022
105224.149.160.0/22224.149.160.1 to 224.149.163.254224.149.163.2551,022
106224.149.164.0/22224.149.164.1 to 224.149.167.254224.149.167.2551,022
107224.149.168.0/22224.149.168.1 to 224.149.171.254224.149.171.2551,022
108224.149.172.0/22224.149.172.1 to 224.149.175.254224.149.175.2551,022
109224.149.176.0/22224.149.176.1 to 224.149.179.254224.149.179.2551,022
110224.149.180.0/22224.149.180.1 to 224.149.183.254224.149.183.2551,022
111224.149.184.0/22224.149.184.1 to 224.149.187.254224.149.187.2551,022
112224.149.188.0/22224.149.188.1 to 224.149.191.254224.149.191.2551,022
113224.149.192.0/22224.149.192.1 to 224.149.195.254224.149.195.2551,022
114224.149.196.0/22224.149.196.1 to 224.149.199.254224.149.199.2551,022
115224.149.200.0/22224.149.200.1 to 224.149.203.254224.149.203.2551,022
116224.149.204.0/22224.149.204.1 to 224.149.207.254224.149.207.2551,022
117224.149.208.0/22224.149.208.1 to 224.149.211.254224.149.211.2551,022
118224.149.212.0/22224.149.212.1 to 224.149.215.254224.149.215.2551,022
119224.149.216.0/22224.149.216.1 to 224.149.219.254224.149.219.2551,022
120224.149.220.0/22224.149.220.1 to 224.149.223.254224.149.223.2551,022
121224.149.224.0/22224.149.224.1 to 224.149.227.254224.149.227.2551,022
122224.149.228.0/22224.149.228.1 to 224.149.231.254224.149.231.2551,022
123224.149.232.0/22224.149.232.1 to 224.149.235.254224.149.235.2551,022
124224.149.236.0/22224.149.236.1 to 224.149.239.254224.149.239.2551,022
125224.149.240.0/22224.149.240.1 to 224.149.243.254224.149.243.2551,022
126224.149.244.0/22224.149.244.1 to 224.149.247.254224.149.247.2551,022
127224.149.248.0/22224.149.248.1 to 224.149.251.254224.149.251.2551,022
128224.149.252.0/22224.149.252.1 to 224.149.255.254224.149.255.2551,022

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.