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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.

Network202.136.0.0/14
Usable hosts262,142
Subnet mask255.252.0.0
Addresses262,144
Network address
202.136.0.0
Broadcast address
202.139.255.255
First usable
202.136.0.1
Last usable
202.139.255.254
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
C (default /24)
As numbers
Hex CA880000 · Integer 3397910528 to 3398172671
Reverse DNS zones
136.202.in-addr.arpa
137.202.in-addr.arpa
138.202.in-addr.arpa
139.202.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
Address11001010.10001000.00000000.00000000202.136.0.0
Subnet mask11111111.11111100.00000000.00000000255.252.0.0
Network11001010.10001000.00000000.00000000202.136.0.0
Broadcast11001010.10001011.11111111.11111111202.139.255.255
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)

202.136.0.0/14 makes 128 subnets of /21.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1202.136.0.0/21202.136.0.1 to 202.136.7.254202.136.7.2552,046
2202.136.8.0/21202.136.8.1 to 202.136.15.254202.136.15.2552,046
3202.136.16.0/21202.136.16.1 to 202.136.23.254202.136.23.2552,046
4202.136.24.0/21202.136.24.1 to 202.136.31.254202.136.31.2552,046
5202.136.32.0/21202.136.32.1 to 202.136.39.254202.136.39.2552,046
6202.136.40.0/21202.136.40.1 to 202.136.47.254202.136.47.2552,046
7202.136.48.0/21202.136.48.1 to 202.136.55.254202.136.55.2552,046
8202.136.56.0/21202.136.56.1 to 202.136.63.254202.136.63.2552,046
9202.136.64.0/21202.136.64.1 to 202.136.71.254202.136.71.2552,046
10202.136.72.0/21202.136.72.1 to 202.136.79.254202.136.79.2552,046
11202.136.80.0/21202.136.80.1 to 202.136.87.254202.136.87.2552,046
12202.136.88.0/21202.136.88.1 to 202.136.95.254202.136.95.2552,046
13202.136.96.0/21202.136.96.1 to 202.136.103.254202.136.103.2552,046
14202.136.104.0/21202.136.104.1 to 202.136.111.254202.136.111.2552,046
15202.136.112.0/21202.136.112.1 to 202.136.119.254202.136.119.2552,046
16202.136.120.0/21202.136.120.1 to 202.136.127.254202.136.127.2552,046
17202.136.128.0/21202.136.128.1 to 202.136.135.254202.136.135.2552,046
18202.136.136.0/21202.136.136.1 to 202.136.143.254202.136.143.2552,046
19202.136.144.0/21202.136.144.1 to 202.136.151.254202.136.151.2552,046
20202.136.152.0/21202.136.152.1 to 202.136.159.254202.136.159.2552,046
21202.136.160.0/21202.136.160.1 to 202.136.167.254202.136.167.2552,046
22202.136.168.0/21202.136.168.1 to 202.136.175.254202.136.175.2552,046
23202.136.176.0/21202.136.176.1 to 202.136.183.254202.136.183.2552,046
24202.136.184.0/21202.136.184.1 to 202.136.191.254202.136.191.2552,046
25202.136.192.0/21202.136.192.1 to 202.136.199.254202.136.199.2552,046
26202.136.200.0/21202.136.200.1 to 202.136.207.254202.136.207.2552,046
27202.136.208.0/21202.136.208.1 to 202.136.215.254202.136.215.2552,046
28202.136.216.0/21202.136.216.1 to 202.136.223.254202.136.223.2552,046
29202.136.224.0/21202.136.224.1 to 202.136.231.254202.136.231.2552,046
30202.136.232.0/21202.136.232.1 to 202.136.239.254202.136.239.2552,046
31202.136.240.0/21202.136.240.1 to 202.136.247.254202.136.247.2552,046
32202.136.248.0/21202.136.248.1 to 202.136.255.254202.136.255.2552,046
33202.137.0.0/21202.137.0.1 to 202.137.7.254202.137.7.2552,046
34202.137.8.0/21202.137.8.1 to 202.137.15.254202.137.15.2552,046
35202.137.16.0/21202.137.16.1 to 202.137.23.254202.137.23.2552,046
36202.137.24.0/21202.137.24.1 to 202.137.31.254202.137.31.2552,046
37202.137.32.0/21202.137.32.1 to 202.137.39.254202.137.39.2552,046
38202.137.40.0/21202.137.40.1 to 202.137.47.254202.137.47.2552,046
39202.137.48.0/21202.137.48.1 to 202.137.55.254202.137.55.2552,046
40202.137.56.0/21202.137.56.1 to 202.137.63.254202.137.63.2552,046
41202.137.64.0/21202.137.64.1 to 202.137.71.254202.137.71.2552,046
42202.137.72.0/21202.137.72.1 to 202.137.79.254202.137.79.2552,046
43202.137.80.0/21202.137.80.1 to 202.137.87.254202.137.87.2552,046
44202.137.88.0/21202.137.88.1 to 202.137.95.254202.137.95.2552,046
45202.137.96.0/21202.137.96.1 to 202.137.103.254202.137.103.2552,046
46202.137.104.0/21202.137.104.1 to 202.137.111.254202.137.111.2552,046
47202.137.112.0/21202.137.112.1 to 202.137.119.254202.137.119.2552,046
48202.137.120.0/21202.137.120.1 to 202.137.127.254202.137.127.2552,046
49202.137.128.0/21202.137.128.1 to 202.137.135.254202.137.135.2552,046
50202.137.136.0/21202.137.136.1 to 202.137.143.254202.137.143.2552,046
51202.137.144.0/21202.137.144.1 to 202.137.151.254202.137.151.2552,046
52202.137.152.0/21202.137.152.1 to 202.137.159.254202.137.159.2552,046
53202.137.160.0/21202.137.160.1 to 202.137.167.254202.137.167.2552,046
54202.137.168.0/21202.137.168.1 to 202.137.175.254202.137.175.2552,046
55202.137.176.0/21202.137.176.1 to 202.137.183.254202.137.183.2552,046
56202.137.184.0/21202.137.184.1 to 202.137.191.254202.137.191.2552,046
57202.137.192.0/21202.137.192.1 to 202.137.199.254202.137.199.2552,046
58202.137.200.0/21202.137.200.1 to 202.137.207.254202.137.207.2552,046
59202.137.208.0/21202.137.208.1 to 202.137.215.254202.137.215.2552,046
60202.137.216.0/21202.137.216.1 to 202.137.223.254202.137.223.2552,046
61202.137.224.0/21202.137.224.1 to 202.137.231.254202.137.231.2552,046
62202.137.232.0/21202.137.232.1 to 202.137.239.254202.137.239.2552,046
63202.137.240.0/21202.137.240.1 to 202.137.247.254202.137.247.2552,046
64202.137.248.0/21202.137.248.1 to 202.137.255.254202.137.255.2552,046
65202.138.0.0/21202.138.0.1 to 202.138.7.254202.138.7.2552,046
66202.138.8.0/21202.138.8.1 to 202.138.15.254202.138.15.2552,046
67202.138.16.0/21202.138.16.1 to 202.138.23.254202.138.23.2552,046
68202.138.24.0/21202.138.24.1 to 202.138.31.254202.138.31.2552,046
69202.138.32.0/21202.138.32.1 to 202.138.39.254202.138.39.2552,046
70202.138.40.0/21202.138.40.1 to 202.138.47.254202.138.47.2552,046
71202.138.48.0/21202.138.48.1 to 202.138.55.254202.138.55.2552,046
72202.138.56.0/21202.138.56.1 to 202.138.63.254202.138.63.2552,046
73202.138.64.0/21202.138.64.1 to 202.138.71.254202.138.71.2552,046
74202.138.72.0/21202.138.72.1 to 202.138.79.254202.138.79.2552,046
75202.138.80.0/21202.138.80.1 to 202.138.87.254202.138.87.2552,046
76202.138.88.0/21202.138.88.1 to 202.138.95.254202.138.95.2552,046
77202.138.96.0/21202.138.96.1 to 202.138.103.254202.138.103.2552,046
78202.138.104.0/21202.138.104.1 to 202.138.111.254202.138.111.2552,046
79202.138.112.0/21202.138.112.1 to 202.138.119.254202.138.119.2552,046
80202.138.120.0/21202.138.120.1 to 202.138.127.254202.138.127.2552,046
81202.138.128.0/21202.138.128.1 to 202.138.135.254202.138.135.2552,046
82202.138.136.0/21202.138.136.1 to 202.138.143.254202.138.143.2552,046
83202.138.144.0/21202.138.144.1 to 202.138.151.254202.138.151.2552,046
84202.138.152.0/21202.138.152.1 to 202.138.159.254202.138.159.2552,046
85202.138.160.0/21202.138.160.1 to 202.138.167.254202.138.167.2552,046
86202.138.168.0/21202.138.168.1 to 202.138.175.254202.138.175.2552,046
87202.138.176.0/21202.138.176.1 to 202.138.183.254202.138.183.2552,046
88202.138.184.0/21202.138.184.1 to 202.138.191.254202.138.191.2552,046
89202.138.192.0/21202.138.192.1 to 202.138.199.254202.138.199.2552,046
90202.138.200.0/21202.138.200.1 to 202.138.207.254202.138.207.2552,046
91202.138.208.0/21202.138.208.1 to 202.138.215.254202.138.215.2552,046
92202.138.216.0/21202.138.216.1 to 202.138.223.254202.138.223.2552,046
93202.138.224.0/21202.138.224.1 to 202.138.231.254202.138.231.2552,046
94202.138.232.0/21202.138.232.1 to 202.138.239.254202.138.239.2552,046
95202.138.240.0/21202.138.240.1 to 202.138.247.254202.138.247.2552,046
96202.138.248.0/21202.138.248.1 to 202.138.255.254202.138.255.2552,046
97202.139.0.0/21202.139.0.1 to 202.139.7.254202.139.7.2552,046
98202.139.8.0/21202.139.8.1 to 202.139.15.254202.139.15.2552,046
99202.139.16.0/21202.139.16.1 to 202.139.23.254202.139.23.2552,046
100202.139.24.0/21202.139.24.1 to 202.139.31.254202.139.31.2552,046
101202.139.32.0/21202.139.32.1 to 202.139.39.254202.139.39.2552,046
102202.139.40.0/21202.139.40.1 to 202.139.47.254202.139.47.2552,046
103202.139.48.0/21202.139.48.1 to 202.139.55.254202.139.55.2552,046
104202.139.56.0/21202.139.56.1 to 202.139.63.254202.139.63.2552,046
105202.139.64.0/21202.139.64.1 to 202.139.71.254202.139.71.2552,046
106202.139.72.0/21202.139.72.1 to 202.139.79.254202.139.79.2552,046
107202.139.80.0/21202.139.80.1 to 202.139.87.254202.139.87.2552,046
108202.139.88.0/21202.139.88.1 to 202.139.95.254202.139.95.2552,046
109202.139.96.0/21202.139.96.1 to 202.139.103.254202.139.103.2552,046
110202.139.104.0/21202.139.104.1 to 202.139.111.254202.139.111.2552,046
111202.139.112.0/21202.139.112.1 to 202.139.119.254202.139.119.2552,046
112202.139.120.0/21202.139.120.1 to 202.139.127.254202.139.127.2552,046
113202.139.128.0/21202.139.128.1 to 202.139.135.254202.139.135.2552,046
114202.139.136.0/21202.139.136.1 to 202.139.143.254202.139.143.2552,046
115202.139.144.0/21202.139.144.1 to 202.139.151.254202.139.151.2552,046
116202.139.152.0/21202.139.152.1 to 202.139.159.254202.139.159.2552,046
117202.139.160.0/21202.139.160.1 to 202.139.167.254202.139.167.2552,046
118202.139.168.0/21202.139.168.1 to 202.139.175.254202.139.175.2552,046
119202.139.176.0/21202.139.176.1 to 202.139.183.254202.139.183.2552,046
120202.139.184.0/21202.139.184.1 to 202.139.191.254202.139.191.2552,046
121202.139.192.0/21202.139.192.1 to 202.139.199.254202.139.199.2552,046
122202.139.200.0/21202.139.200.1 to 202.139.207.254202.139.207.2552,046
123202.139.208.0/21202.139.208.1 to 202.139.215.254202.139.215.2552,046
124202.139.216.0/21202.139.216.1 to 202.139.223.254202.139.223.2552,046
125202.139.224.0/21202.139.224.1 to 202.139.231.254202.139.231.2552,046
126202.139.232.0/21202.139.232.1 to 202.139.239.254202.139.239.2552,046
127202.139.240.0/21202.139.240.1 to 202.139.247.254202.139.247.2552,046
128202.139.248.0/21202.139.248.1 to 202.139.255.254202.139.255.2552,046

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.