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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.

Network110.0.0.0/7
Usable hosts33,554,430
Subnet mask254.0.0.0
Addresses33,554,432
Network address
110.0.0.0
Broadcast address
111.255.255.255
First usable
110.0.0.1
Last usable
111.255.255.254
Usable hosts
33,554,430 (33,554,432 less the network and broadcast addresses)
Subnet mask
254.0.0.0
Wildcard mask
1.255.255.255 (Cisco ACLs, OSPF)
Prefix length
/7
Type
Public public
Old class
A (default /8)
As numbers
Hex 6E000000 · Integer 1845493760 to 1879048191
Reverse DNS zones
110.in-addr.arpa
111.in-addr.arpa
/7 is not on a 8-bit boundary, so it takes 2 /8 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address01101110.00000000.00000000.00000000110.0.0.0
Subnet mask11111110.00000000.00000000.00000000254.0.0.0
Network01101110.00000000.00000000.00000000110.0.0.0
Broadcast01101111.11111111.11111111.11111111111.255.255.255
Split into smaller subnets/14
/8 (2)/9 (4)/10 (8)/11 (16)/12 (32)/13 (64)/14 (128)/15 (256)/16 (512)/17 (1,024)/18 (2,048)/19 (4,096)

110.0.0.0/7 makes 128 subnets of /14.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1110.0.0.0/14110.0.0.1 to 110.3.255.254110.3.255.255262,142
2110.4.0.0/14110.4.0.1 to 110.7.255.254110.7.255.255262,142
3110.8.0.0/14110.8.0.1 to 110.11.255.254110.11.255.255262,142
4110.12.0.0/14110.12.0.1 to 110.15.255.254110.15.255.255262,142
5110.16.0.0/14110.16.0.1 to 110.19.255.254110.19.255.255262,142
6110.20.0.0/14110.20.0.1 to 110.23.255.254110.23.255.255262,142
7110.24.0.0/14110.24.0.1 to 110.27.255.254110.27.255.255262,142
8110.28.0.0/14110.28.0.1 to 110.31.255.254110.31.255.255262,142
9110.32.0.0/14110.32.0.1 to 110.35.255.254110.35.255.255262,142
10110.36.0.0/14110.36.0.1 to 110.39.255.254110.39.255.255262,142
11110.40.0.0/14110.40.0.1 to 110.43.255.254110.43.255.255262,142
12110.44.0.0/14110.44.0.1 to 110.47.255.254110.47.255.255262,142
13110.48.0.0/14110.48.0.1 to 110.51.255.254110.51.255.255262,142
14110.52.0.0/14110.52.0.1 to 110.55.255.254110.55.255.255262,142
15110.56.0.0/14110.56.0.1 to 110.59.255.254110.59.255.255262,142
16110.60.0.0/14110.60.0.1 to 110.63.255.254110.63.255.255262,142
17110.64.0.0/14110.64.0.1 to 110.67.255.254110.67.255.255262,142
18110.68.0.0/14110.68.0.1 to 110.71.255.254110.71.255.255262,142
19110.72.0.0/14110.72.0.1 to 110.75.255.254110.75.255.255262,142
20110.76.0.0/14110.76.0.1 to 110.79.255.254110.79.255.255262,142
21110.80.0.0/14110.80.0.1 to 110.83.255.254110.83.255.255262,142
22110.84.0.0/14110.84.0.1 to 110.87.255.254110.87.255.255262,142
23110.88.0.0/14110.88.0.1 to 110.91.255.254110.91.255.255262,142
24110.92.0.0/14110.92.0.1 to 110.95.255.254110.95.255.255262,142
25110.96.0.0/14110.96.0.1 to 110.99.255.254110.99.255.255262,142
26110.100.0.0/14110.100.0.1 to 110.103.255.254110.103.255.255262,142
27110.104.0.0/14110.104.0.1 to 110.107.255.254110.107.255.255262,142
28110.108.0.0/14110.108.0.1 to 110.111.255.254110.111.255.255262,142
29110.112.0.0/14110.112.0.1 to 110.115.255.254110.115.255.255262,142
30110.116.0.0/14110.116.0.1 to 110.119.255.254110.119.255.255262,142
31110.120.0.0/14110.120.0.1 to 110.123.255.254110.123.255.255262,142
32110.124.0.0/14110.124.0.1 to 110.127.255.254110.127.255.255262,142
33110.128.0.0/14110.128.0.1 to 110.131.255.254110.131.255.255262,142
34110.132.0.0/14110.132.0.1 to 110.135.255.254110.135.255.255262,142
35110.136.0.0/14110.136.0.1 to 110.139.255.254110.139.255.255262,142
36110.140.0.0/14110.140.0.1 to 110.143.255.254110.143.255.255262,142
37110.144.0.0/14110.144.0.1 to 110.147.255.254110.147.255.255262,142
38110.148.0.0/14110.148.0.1 to 110.151.255.254110.151.255.255262,142
39110.152.0.0/14110.152.0.1 to 110.155.255.254110.155.255.255262,142
40110.156.0.0/14110.156.0.1 to 110.159.255.254110.159.255.255262,142
41110.160.0.0/14110.160.0.1 to 110.163.255.254110.163.255.255262,142
42110.164.0.0/14110.164.0.1 to 110.167.255.254110.167.255.255262,142
43110.168.0.0/14110.168.0.1 to 110.171.255.254110.171.255.255262,142
44110.172.0.0/14110.172.0.1 to 110.175.255.254110.175.255.255262,142
45110.176.0.0/14110.176.0.1 to 110.179.255.254110.179.255.255262,142
46110.180.0.0/14110.180.0.1 to 110.183.255.254110.183.255.255262,142
47110.184.0.0/14110.184.0.1 to 110.187.255.254110.187.255.255262,142
48110.188.0.0/14110.188.0.1 to 110.191.255.254110.191.255.255262,142
49110.192.0.0/14110.192.0.1 to 110.195.255.254110.195.255.255262,142
50110.196.0.0/14110.196.0.1 to 110.199.255.254110.199.255.255262,142
51110.200.0.0/14110.200.0.1 to 110.203.255.254110.203.255.255262,142
52110.204.0.0/14110.204.0.1 to 110.207.255.254110.207.255.255262,142
53110.208.0.0/14110.208.0.1 to 110.211.255.254110.211.255.255262,142
54110.212.0.0/14110.212.0.1 to 110.215.255.254110.215.255.255262,142
55110.216.0.0/14110.216.0.1 to 110.219.255.254110.219.255.255262,142
56110.220.0.0/14110.220.0.1 to 110.223.255.254110.223.255.255262,142
57110.224.0.0/14110.224.0.1 to 110.227.255.254110.227.255.255262,142
58110.228.0.0/14110.228.0.1 to 110.231.255.254110.231.255.255262,142
59110.232.0.0/14110.232.0.1 to 110.235.255.254110.235.255.255262,142
60110.236.0.0/14110.236.0.1 to 110.239.255.254110.239.255.255262,142
61110.240.0.0/14110.240.0.1 to 110.243.255.254110.243.255.255262,142
62110.244.0.0/14110.244.0.1 to 110.247.255.254110.247.255.255262,142
63110.248.0.0/14110.248.0.1 to 110.251.255.254110.251.255.255262,142
64110.252.0.0/14110.252.0.1 to 110.255.255.254110.255.255.255262,142
65111.0.0.0/14111.0.0.1 to 111.3.255.254111.3.255.255262,142
66111.4.0.0/14111.4.0.1 to 111.7.255.254111.7.255.255262,142
67111.8.0.0/14111.8.0.1 to 111.11.255.254111.11.255.255262,142
68111.12.0.0/14111.12.0.1 to 111.15.255.254111.15.255.255262,142
69111.16.0.0/14111.16.0.1 to 111.19.255.254111.19.255.255262,142
70111.20.0.0/14111.20.0.1 to 111.23.255.254111.23.255.255262,142
71111.24.0.0/14111.24.0.1 to 111.27.255.254111.27.255.255262,142
72111.28.0.0/14111.28.0.1 to 111.31.255.254111.31.255.255262,142
73111.32.0.0/14111.32.0.1 to 111.35.255.254111.35.255.255262,142
74111.36.0.0/14111.36.0.1 to 111.39.255.254111.39.255.255262,142
75111.40.0.0/14111.40.0.1 to 111.43.255.254111.43.255.255262,142
76111.44.0.0/14111.44.0.1 to 111.47.255.254111.47.255.255262,142
77111.48.0.0/14111.48.0.1 to 111.51.255.254111.51.255.255262,142
78111.52.0.0/14111.52.0.1 to 111.55.255.254111.55.255.255262,142
79111.56.0.0/14111.56.0.1 to 111.59.255.254111.59.255.255262,142
80111.60.0.0/14111.60.0.1 to 111.63.255.254111.63.255.255262,142
81111.64.0.0/14111.64.0.1 to 111.67.255.254111.67.255.255262,142
82111.68.0.0/14111.68.0.1 to 111.71.255.254111.71.255.255262,142
83111.72.0.0/14111.72.0.1 to 111.75.255.254111.75.255.255262,142
84111.76.0.0/14111.76.0.1 to 111.79.255.254111.79.255.255262,142
85111.80.0.0/14111.80.0.1 to 111.83.255.254111.83.255.255262,142
86111.84.0.0/14111.84.0.1 to 111.87.255.254111.87.255.255262,142
87111.88.0.0/14111.88.0.1 to 111.91.255.254111.91.255.255262,142
88111.92.0.0/14111.92.0.1 to 111.95.255.254111.95.255.255262,142
89111.96.0.0/14111.96.0.1 to 111.99.255.254111.99.255.255262,142
90111.100.0.0/14111.100.0.1 to 111.103.255.254111.103.255.255262,142
91111.104.0.0/14111.104.0.1 to 111.107.255.254111.107.255.255262,142
92111.108.0.0/14111.108.0.1 to 111.111.255.254111.111.255.255262,142
93111.112.0.0/14111.112.0.1 to 111.115.255.254111.115.255.255262,142
94111.116.0.0/14111.116.0.1 to 111.119.255.254111.119.255.255262,142
95111.120.0.0/14111.120.0.1 to 111.123.255.254111.123.255.255262,142
96111.124.0.0/14111.124.0.1 to 111.127.255.254111.127.255.255262,142
97111.128.0.0/14111.128.0.1 to 111.131.255.254111.131.255.255262,142
98111.132.0.0/14111.132.0.1 to 111.135.255.254111.135.255.255262,142
99111.136.0.0/14111.136.0.1 to 111.139.255.254111.139.255.255262,142
100111.140.0.0/14111.140.0.1 to 111.143.255.254111.143.255.255262,142
101111.144.0.0/14111.144.0.1 to 111.147.255.254111.147.255.255262,142
102111.148.0.0/14111.148.0.1 to 111.151.255.254111.151.255.255262,142
103111.152.0.0/14111.152.0.1 to 111.155.255.254111.155.255.255262,142
104111.156.0.0/14111.156.0.1 to 111.159.255.254111.159.255.255262,142
105111.160.0.0/14111.160.0.1 to 111.163.255.254111.163.255.255262,142
106111.164.0.0/14111.164.0.1 to 111.167.255.254111.167.255.255262,142
107111.168.0.0/14111.168.0.1 to 111.171.255.254111.171.255.255262,142
108111.172.0.0/14111.172.0.1 to 111.175.255.254111.175.255.255262,142
109111.176.0.0/14111.176.0.1 to 111.179.255.254111.179.255.255262,142
110111.180.0.0/14111.180.0.1 to 111.183.255.254111.183.255.255262,142
111111.184.0.0/14111.184.0.1 to 111.187.255.254111.187.255.255262,142
112111.188.0.0/14111.188.0.1 to 111.191.255.254111.191.255.255262,142
113111.192.0.0/14111.192.0.1 to 111.195.255.254111.195.255.255262,142
114111.196.0.0/14111.196.0.1 to 111.199.255.254111.199.255.255262,142
115111.200.0.0/14111.200.0.1 to 111.203.255.254111.203.255.255262,142
116111.204.0.0/14111.204.0.1 to 111.207.255.254111.207.255.255262,142
117111.208.0.0/14111.208.0.1 to 111.211.255.254111.211.255.255262,142
118111.212.0.0/14111.212.0.1 to 111.215.255.254111.215.255.255262,142
119111.216.0.0/14111.216.0.1 to 111.219.255.254111.219.255.255262,142
120111.220.0.0/14111.220.0.1 to 111.223.255.254111.223.255.255262,142
121111.224.0.0/14111.224.0.1 to 111.227.255.254111.227.255.255262,142
122111.228.0.0/14111.228.0.1 to 111.231.255.254111.231.255.255262,142
123111.232.0.0/14111.232.0.1 to 111.235.255.254111.235.255.255262,142
124111.236.0.0/14111.236.0.1 to 111.239.255.254111.239.255.255262,142
125111.240.0.0/14111.240.0.1 to 111.243.255.254111.243.255.255262,142
126111.244.0.0/14111.244.0.1 to 111.247.255.254111.247.255.255262,142
127111.248.0.0/14111.248.0.1 to 111.251.255.254111.251.255.255262,142
128111.252.0.0/14111.252.0.1 to 111.255.255.254111.255.255.255262,142

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.