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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.

Network141.64.0.0/14
Usable hosts262,142
Subnet mask255.252.0.0
Addresses262,144
Network address
141.64.0.0
Broadcast address
141.67.255.255
First usable
141.64.0.1
Last usable
141.67.255.254
Usable hosts
262,142 (262,144 less the network and broadcast addresses)
Subnet mask
255.252.0.0
Wildcard mask
0.3.255.255 (Cisco ACLs, OSPF)
Prefix length
/14
Type
Public public
Old class
B (default /16)
As numbers
Hex 8D400000 · Integer 2369781760 to 2370043903
Reverse DNS zones
64.141.in-addr.arpa
65.141.in-addr.arpa
66.141.in-addr.arpa
67.141.in-addr.arpa
/14 is not on a 8-bit boundary, so it takes 4 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address10001101.01000000.00000000.00000000141.64.0.0
Subnet mask11111111.11111100.00000000.00000000255.252.0.0
Network10001101.01000000.00000000.00000000141.64.0.0
Broadcast10001101.01000011.11111111.11111111141.67.255.255
Split into smaller subnets/21
/15 (2)/16 (4)/17 (8)/18 (16)/19 (32)/20 (64)/21 (128)/22 (256)/23 (512)/24 (1,024)/25 (2,048)/26 (4,096)

141.64.0.0/14 makes 128 subnets of /21.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1141.64.0.0/21141.64.0.1 to 141.64.7.254141.64.7.2552,046
2141.64.8.0/21141.64.8.1 to 141.64.15.254141.64.15.2552,046
3141.64.16.0/21141.64.16.1 to 141.64.23.254141.64.23.2552,046
4141.64.24.0/21141.64.24.1 to 141.64.31.254141.64.31.2552,046
5141.64.32.0/21141.64.32.1 to 141.64.39.254141.64.39.2552,046
6141.64.40.0/21141.64.40.1 to 141.64.47.254141.64.47.2552,046
7141.64.48.0/21141.64.48.1 to 141.64.55.254141.64.55.2552,046
8141.64.56.0/21141.64.56.1 to 141.64.63.254141.64.63.2552,046
9141.64.64.0/21141.64.64.1 to 141.64.71.254141.64.71.2552,046
10141.64.72.0/21141.64.72.1 to 141.64.79.254141.64.79.2552,046
11141.64.80.0/21141.64.80.1 to 141.64.87.254141.64.87.2552,046
12141.64.88.0/21141.64.88.1 to 141.64.95.254141.64.95.2552,046
13141.64.96.0/21141.64.96.1 to 141.64.103.254141.64.103.2552,046
14141.64.104.0/21141.64.104.1 to 141.64.111.254141.64.111.2552,046
15141.64.112.0/21141.64.112.1 to 141.64.119.254141.64.119.2552,046
16141.64.120.0/21141.64.120.1 to 141.64.127.254141.64.127.2552,046
17141.64.128.0/21141.64.128.1 to 141.64.135.254141.64.135.2552,046
18141.64.136.0/21141.64.136.1 to 141.64.143.254141.64.143.2552,046
19141.64.144.0/21141.64.144.1 to 141.64.151.254141.64.151.2552,046
20141.64.152.0/21141.64.152.1 to 141.64.159.254141.64.159.2552,046
21141.64.160.0/21141.64.160.1 to 141.64.167.254141.64.167.2552,046
22141.64.168.0/21141.64.168.1 to 141.64.175.254141.64.175.2552,046
23141.64.176.0/21141.64.176.1 to 141.64.183.254141.64.183.2552,046
24141.64.184.0/21141.64.184.1 to 141.64.191.254141.64.191.2552,046
25141.64.192.0/21141.64.192.1 to 141.64.199.254141.64.199.2552,046
26141.64.200.0/21141.64.200.1 to 141.64.207.254141.64.207.2552,046
27141.64.208.0/21141.64.208.1 to 141.64.215.254141.64.215.2552,046
28141.64.216.0/21141.64.216.1 to 141.64.223.254141.64.223.2552,046
29141.64.224.0/21141.64.224.1 to 141.64.231.254141.64.231.2552,046
30141.64.232.0/21141.64.232.1 to 141.64.239.254141.64.239.2552,046
31141.64.240.0/21141.64.240.1 to 141.64.247.254141.64.247.2552,046
32141.64.248.0/21141.64.248.1 to 141.64.255.254141.64.255.2552,046
33141.65.0.0/21141.65.0.1 to 141.65.7.254141.65.7.2552,046
34141.65.8.0/21141.65.8.1 to 141.65.15.254141.65.15.2552,046
35141.65.16.0/21141.65.16.1 to 141.65.23.254141.65.23.2552,046
36141.65.24.0/21141.65.24.1 to 141.65.31.254141.65.31.2552,046
37141.65.32.0/21141.65.32.1 to 141.65.39.254141.65.39.2552,046
38141.65.40.0/21141.65.40.1 to 141.65.47.254141.65.47.2552,046
39141.65.48.0/21141.65.48.1 to 141.65.55.254141.65.55.2552,046
40141.65.56.0/21141.65.56.1 to 141.65.63.254141.65.63.2552,046
41141.65.64.0/21141.65.64.1 to 141.65.71.254141.65.71.2552,046
42141.65.72.0/21141.65.72.1 to 141.65.79.254141.65.79.2552,046
43141.65.80.0/21141.65.80.1 to 141.65.87.254141.65.87.2552,046
44141.65.88.0/21141.65.88.1 to 141.65.95.254141.65.95.2552,046
45141.65.96.0/21141.65.96.1 to 141.65.103.254141.65.103.2552,046
46141.65.104.0/21141.65.104.1 to 141.65.111.254141.65.111.2552,046
47141.65.112.0/21141.65.112.1 to 141.65.119.254141.65.119.2552,046
48141.65.120.0/21141.65.120.1 to 141.65.127.254141.65.127.2552,046
49141.65.128.0/21141.65.128.1 to 141.65.135.254141.65.135.2552,046
50141.65.136.0/21141.65.136.1 to 141.65.143.254141.65.143.2552,046
51141.65.144.0/21141.65.144.1 to 141.65.151.254141.65.151.2552,046
52141.65.152.0/21141.65.152.1 to 141.65.159.254141.65.159.2552,046
53141.65.160.0/21141.65.160.1 to 141.65.167.254141.65.167.2552,046
54141.65.168.0/21141.65.168.1 to 141.65.175.254141.65.175.2552,046
55141.65.176.0/21141.65.176.1 to 141.65.183.254141.65.183.2552,046
56141.65.184.0/21141.65.184.1 to 141.65.191.254141.65.191.2552,046
57141.65.192.0/21141.65.192.1 to 141.65.199.254141.65.199.2552,046
58141.65.200.0/21141.65.200.1 to 141.65.207.254141.65.207.2552,046
59141.65.208.0/21141.65.208.1 to 141.65.215.254141.65.215.2552,046
60141.65.216.0/21141.65.216.1 to 141.65.223.254141.65.223.2552,046
61141.65.224.0/21141.65.224.1 to 141.65.231.254141.65.231.2552,046
62141.65.232.0/21141.65.232.1 to 141.65.239.254141.65.239.2552,046
63141.65.240.0/21141.65.240.1 to 141.65.247.254141.65.247.2552,046
64141.65.248.0/21141.65.248.1 to 141.65.255.254141.65.255.2552,046
65141.66.0.0/21141.66.0.1 to 141.66.7.254141.66.7.2552,046
66141.66.8.0/21141.66.8.1 to 141.66.15.254141.66.15.2552,046
67141.66.16.0/21141.66.16.1 to 141.66.23.254141.66.23.2552,046
68141.66.24.0/21141.66.24.1 to 141.66.31.254141.66.31.2552,046
69141.66.32.0/21141.66.32.1 to 141.66.39.254141.66.39.2552,046
70141.66.40.0/21141.66.40.1 to 141.66.47.254141.66.47.2552,046
71141.66.48.0/21141.66.48.1 to 141.66.55.254141.66.55.2552,046
72141.66.56.0/21141.66.56.1 to 141.66.63.254141.66.63.2552,046
73141.66.64.0/21141.66.64.1 to 141.66.71.254141.66.71.2552,046
74141.66.72.0/21141.66.72.1 to 141.66.79.254141.66.79.2552,046
75141.66.80.0/21141.66.80.1 to 141.66.87.254141.66.87.2552,046
76141.66.88.0/21141.66.88.1 to 141.66.95.254141.66.95.2552,046
77141.66.96.0/21141.66.96.1 to 141.66.103.254141.66.103.2552,046
78141.66.104.0/21141.66.104.1 to 141.66.111.254141.66.111.2552,046
79141.66.112.0/21141.66.112.1 to 141.66.119.254141.66.119.2552,046
80141.66.120.0/21141.66.120.1 to 141.66.127.254141.66.127.2552,046
81141.66.128.0/21141.66.128.1 to 141.66.135.254141.66.135.2552,046
82141.66.136.0/21141.66.136.1 to 141.66.143.254141.66.143.2552,046
83141.66.144.0/21141.66.144.1 to 141.66.151.254141.66.151.2552,046
84141.66.152.0/21141.66.152.1 to 141.66.159.254141.66.159.2552,046
85141.66.160.0/21141.66.160.1 to 141.66.167.254141.66.167.2552,046
86141.66.168.0/21141.66.168.1 to 141.66.175.254141.66.175.2552,046
87141.66.176.0/21141.66.176.1 to 141.66.183.254141.66.183.2552,046
88141.66.184.0/21141.66.184.1 to 141.66.191.254141.66.191.2552,046
89141.66.192.0/21141.66.192.1 to 141.66.199.254141.66.199.2552,046
90141.66.200.0/21141.66.200.1 to 141.66.207.254141.66.207.2552,046
91141.66.208.0/21141.66.208.1 to 141.66.215.254141.66.215.2552,046
92141.66.216.0/21141.66.216.1 to 141.66.223.254141.66.223.2552,046
93141.66.224.0/21141.66.224.1 to 141.66.231.254141.66.231.2552,046
94141.66.232.0/21141.66.232.1 to 141.66.239.254141.66.239.2552,046
95141.66.240.0/21141.66.240.1 to 141.66.247.254141.66.247.2552,046
96141.66.248.0/21141.66.248.1 to 141.66.255.254141.66.255.2552,046
97141.67.0.0/21141.67.0.1 to 141.67.7.254141.67.7.2552,046
98141.67.8.0/21141.67.8.1 to 141.67.15.254141.67.15.2552,046
99141.67.16.0/21141.67.16.1 to 141.67.23.254141.67.23.2552,046
100141.67.24.0/21141.67.24.1 to 141.67.31.254141.67.31.2552,046
101141.67.32.0/21141.67.32.1 to 141.67.39.254141.67.39.2552,046
102141.67.40.0/21141.67.40.1 to 141.67.47.254141.67.47.2552,046
103141.67.48.0/21141.67.48.1 to 141.67.55.254141.67.55.2552,046
104141.67.56.0/21141.67.56.1 to 141.67.63.254141.67.63.2552,046
105141.67.64.0/21141.67.64.1 to 141.67.71.254141.67.71.2552,046
106141.67.72.0/21141.67.72.1 to 141.67.79.254141.67.79.2552,046
107141.67.80.0/21141.67.80.1 to 141.67.87.254141.67.87.2552,046
108141.67.88.0/21141.67.88.1 to 141.67.95.254141.67.95.2552,046
109141.67.96.0/21141.67.96.1 to 141.67.103.254141.67.103.2552,046
110141.67.104.0/21141.67.104.1 to 141.67.111.254141.67.111.2552,046
111141.67.112.0/21141.67.112.1 to 141.67.119.254141.67.119.2552,046
112141.67.120.0/21141.67.120.1 to 141.67.127.254141.67.127.2552,046
113141.67.128.0/21141.67.128.1 to 141.67.135.254141.67.135.2552,046
114141.67.136.0/21141.67.136.1 to 141.67.143.254141.67.143.2552,046
115141.67.144.0/21141.67.144.1 to 141.67.151.254141.67.151.2552,046
116141.67.152.0/21141.67.152.1 to 141.67.159.254141.67.159.2552,046
117141.67.160.0/21141.67.160.1 to 141.67.167.254141.67.167.2552,046
118141.67.168.0/21141.67.168.1 to 141.67.175.254141.67.175.2552,046
119141.67.176.0/21141.67.176.1 to 141.67.183.254141.67.183.2552,046
120141.67.184.0/21141.67.184.1 to 141.67.191.254141.67.191.2552,046
121141.67.192.0/21141.67.192.1 to 141.67.199.254141.67.199.2552,046
122141.67.200.0/21141.67.200.1 to 141.67.207.254141.67.207.2552,046
123141.67.208.0/21141.67.208.1 to 141.67.215.254141.67.215.2552,046
124141.67.216.0/21141.67.216.1 to 141.67.223.254141.67.223.2552,046
125141.67.224.0/21141.67.224.1 to 141.67.231.254141.67.231.2552,046
126141.67.232.0/21141.67.232.1 to 141.67.239.254141.67.239.2552,046
127141.67.240.0/21141.67.240.1 to 141.67.247.254141.67.247.2552,046
128141.67.248.0/21141.67.248.1 to 141.67.255.254141.67.255.2552,046

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.