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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.

Network146.136.0.0/13
Usable hosts524,286
Subnet mask255.248.0.0
Addresses524,288
Network address
146.136.0.0
Broadcast address
146.143.255.255
First usable
146.136.0.1
Last usable
146.143.255.254
Usable hosts
524,286 (524,288 less the network and broadcast addresses)
Subnet mask
255.248.0.0
Wildcard mask
0.7.255.255 (Cisco ACLs, OSPF)
Prefix length
/13
Type
Public public
Old class
B (default /16)
As numbers
Hex 92880000 · Integer 2458386432 to 2458910719
Reverse DNS zones
136.146.in-addr.arpa
137.146.in-addr.arpa
138.146.in-addr.arpa
139.146.in-addr.arpa
140.146.in-addr.arpa
141.146.in-addr.arpa
142.146.in-addr.arpa
143.146.in-addr.arpa
/13 is not on a 8-bit boundary, so it takes 8 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address10010010.10001000.00000000.00000000146.136.0.0
Subnet mask11111111.11111000.00000000.00000000255.248.0.0
Network10010010.10001000.00000000.00000000146.136.0.0
Broadcast10010010.10001111.11111111.11111111146.143.255.255
Split into smaller subnets/20
/14 (2)/15 (4)/16 (8)/17 (16)/18 (32)/19 (64)/20 (128)/21 (256)/22 (512)/23 (1,024)/24 (2,048)/25 (4,096)

146.136.0.0/13 makes 128 subnets of /20.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1146.136.0.0/20146.136.0.1 to 146.136.15.254146.136.15.2554,094
2146.136.16.0/20146.136.16.1 to 146.136.31.254146.136.31.2554,094
3146.136.32.0/20146.136.32.1 to 146.136.47.254146.136.47.2554,094
4146.136.48.0/20146.136.48.1 to 146.136.63.254146.136.63.2554,094
5146.136.64.0/20146.136.64.1 to 146.136.79.254146.136.79.2554,094
6146.136.80.0/20146.136.80.1 to 146.136.95.254146.136.95.2554,094
7146.136.96.0/20146.136.96.1 to 146.136.111.254146.136.111.2554,094
8146.136.112.0/20146.136.112.1 to 146.136.127.254146.136.127.2554,094
9146.136.128.0/20146.136.128.1 to 146.136.143.254146.136.143.2554,094
10146.136.144.0/20146.136.144.1 to 146.136.159.254146.136.159.2554,094
11146.136.160.0/20146.136.160.1 to 146.136.175.254146.136.175.2554,094
12146.136.176.0/20146.136.176.1 to 146.136.191.254146.136.191.2554,094
13146.136.192.0/20146.136.192.1 to 146.136.207.254146.136.207.2554,094
14146.136.208.0/20146.136.208.1 to 146.136.223.254146.136.223.2554,094
15146.136.224.0/20146.136.224.1 to 146.136.239.254146.136.239.2554,094
16146.136.240.0/20146.136.240.1 to 146.136.255.254146.136.255.2554,094
17146.137.0.0/20146.137.0.1 to 146.137.15.254146.137.15.2554,094
18146.137.16.0/20146.137.16.1 to 146.137.31.254146.137.31.2554,094
19146.137.32.0/20146.137.32.1 to 146.137.47.254146.137.47.2554,094
20146.137.48.0/20146.137.48.1 to 146.137.63.254146.137.63.2554,094
21146.137.64.0/20146.137.64.1 to 146.137.79.254146.137.79.2554,094
22146.137.80.0/20146.137.80.1 to 146.137.95.254146.137.95.2554,094
23146.137.96.0/20146.137.96.1 to 146.137.111.254146.137.111.2554,094
24146.137.112.0/20146.137.112.1 to 146.137.127.254146.137.127.2554,094
25146.137.128.0/20146.137.128.1 to 146.137.143.254146.137.143.2554,094
26146.137.144.0/20146.137.144.1 to 146.137.159.254146.137.159.2554,094
27146.137.160.0/20146.137.160.1 to 146.137.175.254146.137.175.2554,094
28146.137.176.0/20146.137.176.1 to 146.137.191.254146.137.191.2554,094
29146.137.192.0/20146.137.192.1 to 146.137.207.254146.137.207.2554,094
30146.137.208.0/20146.137.208.1 to 146.137.223.254146.137.223.2554,094
31146.137.224.0/20146.137.224.1 to 146.137.239.254146.137.239.2554,094
32146.137.240.0/20146.137.240.1 to 146.137.255.254146.137.255.2554,094
33146.138.0.0/20146.138.0.1 to 146.138.15.254146.138.15.2554,094
34146.138.16.0/20146.138.16.1 to 146.138.31.254146.138.31.2554,094
35146.138.32.0/20146.138.32.1 to 146.138.47.254146.138.47.2554,094
36146.138.48.0/20146.138.48.1 to 146.138.63.254146.138.63.2554,094
37146.138.64.0/20146.138.64.1 to 146.138.79.254146.138.79.2554,094
38146.138.80.0/20146.138.80.1 to 146.138.95.254146.138.95.2554,094
39146.138.96.0/20146.138.96.1 to 146.138.111.254146.138.111.2554,094
40146.138.112.0/20146.138.112.1 to 146.138.127.254146.138.127.2554,094
41146.138.128.0/20146.138.128.1 to 146.138.143.254146.138.143.2554,094
42146.138.144.0/20146.138.144.1 to 146.138.159.254146.138.159.2554,094
43146.138.160.0/20146.138.160.1 to 146.138.175.254146.138.175.2554,094
44146.138.176.0/20146.138.176.1 to 146.138.191.254146.138.191.2554,094
45146.138.192.0/20146.138.192.1 to 146.138.207.254146.138.207.2554,094
46146.138.208.0/20146.138.208.1 to 146.138.223.254146.138.223.2554,094
47146.138.224.0/20146.138.224.1 to 146.138.239.254146.138.239.2554,094
48146.138.240.0/20146.138.240.1 to 146.138.255.254146.138.255.2554,094
49146.139.0.0/20146.139.0.1 to 146.139.15.254146.139.15.2554,094
50146.139.16.0/20146.139.16.1 to 146.139.31.254146.139.31.2554,094
51146.139.32.0/20146.139.32.1 to 146.139.47.254146.139.47.2554,094
52146.139.48.0/20146.139.48.1 to 146.139.63.254146.139.63.2554,094
53146.139.64.0/20146.139.64.1 to 146.139.79.254146.139.79.2554,094
54146.139.80.0/20146.139.80.1 to 146.139.95.254146.139.95.2554,094
55146.139.96.0/20146.139.96.1 to 146.139.111.254146.139.111.2554,094
56146.139.112.0/20146.139.112.1 to 146.139.127.254146.139.127.2554,094
57146.139.128.0/20146.139.128.1 to 146.139.143.254146.139.143.2554,094
58146.139.144.0/20146.139.144.1 to 146.139.159.254146.139.159.2554,094
59146.139.160.0/20146.139.160.1 to 146.139.175.254146.139.175.2554,094
60146.139.176.0/20146.139.176.1 to 146.139.191.254146.139.191.2554,094
61146.139.192.0/20146.139.192.1 to 146.139.207.254146.139.207.2554,094
62146.139.208.0/20146.139.208.1 to 146.139.223.254146.139.223.2554,094
63146.139.224.0/20146.139.224.1 to 146.139.239.254146.139.239.2554,094
64146.139.240.0/20146.139.240.1 to 146.139.255.254146.139.255.2554,094
65146.140.0.0/20146.140.0.1 to 146.140.15.254146.140.15.2554,094
66146.140.16.0/20146.140.16.1 to 146.140.31.254146.140.31.2554,094
67146.140.32.0/20146.140.32.1 to 146.140.47.254146.140.47.2554,094
68146.140.48.0/20146.140.48.1 to 146.140.63.254146.140.63.2554,094
69146.140.64.0/20146.140.64.1 to 146.140.79.254146.140.79.2554,094
70146.140.80.0/20146.140.80.1 to 146.140.95.254146.140.95.2554,094
71146.140.96.0/20146.140.96.1 to 146.140.111.254146.140.111.2554,094
72146.140.112.0/20146.140.112.1 to 146.140.127.254146.140.127.2554,094
73146.140.128.0/20146.140.128.1 to 146.140.143.254146.140.143.2554,094
74146.140.144.0/20146.140.144.1 to 146.140.159.254146.140.159.2554,094
75146.140.160.0/20146.140.160.1 to 146.140.175.254146.140.175.2554,094
76146.140.176.0/20146.140.176.1 to 146.140.191.254146.140.191.2554,094
77146.140.192.0/20146.140.192.1 to 146.140.207.254146.140.207.2554,094
78146.140.208.0/20146.140.208.1 to 146.140.223.254146.140.223.2554,094
79146.140.224.0/20146.140.224.1 to 146.140.239.254146.140.239.2554,094
80146.140.240.0/20146.140.240.1 to 146.140.255.254146.140.255.2554,094
81146.141.0.0/20146.141.0.1 to 146.141.15.254146.141.15.2554,094
82146.141.16.0/20146.141.16.1 to 146.141.31.254146.141.31.2554,094
83146.141.32.0/20146.141.32.1 to 146.141.47.254146.141.47.2554,094
84146.141.48.0/20146.141.48.1 to 146.141.63.254146.141.63.2554,094
85146.141.64.0/20146.141.64.1 to 146.141.79.254146.141.79.2554,094
86146.141.80.0/20146.141.80.1 to 146.141.95.254146.141.95.2554,094
87146.141.96.0/20146.141.96.1 to 146.141.111.254146.141.111.2554,094
88146.141.112.0/20146.141.112.1 to 146.141.127.254146.141.127.2554,094
89146.141.128.0/20146.141.128.1 to 146.141.143.254146.141.143.2554,094
90146.141.144.0/20146.141.144.1 to 146.141.159.254146.141.159.2554,094
91146.141.160.0/20146.141.160.1 to 146.141.175.254146.141.175.2554,094
92146.141.176.0/20146.141.176.1 to 146.141.191.254146.141.191.2554,094
93146.141.192.0/20146.141.192.1 to 146.141.207.254146.141.207.2554,094
94146.141.208.0/20146.141.208.1 to 146.141.223.254146.141.223.2554,094
95146.141.224.0/20146.141.224.1 to 146.141.239.254146.141.239.2554,094
96146.141.240.0/20146.141.240.1 to 146.141.255.254146.141.255.2554,094
97146.142.0.0/20146.142.0.1 to 146.142.15.254146.142.15.2554,094
98146.142.16.0/20146.142.16.1 to 146.142.31.254146.142.31.2554,094
99146.142.32.0/20146.142.32.1 to 146.142.47.254146.142.47.2554,094
100146.142.48.0/20146.142.48.1 to 146.142.63.254146.142.63.2554,094
101146.142.64.0/20146.142.64.1 to 146.142.79.254146.142.79.2554,094
102146.142.80.0/20146.142.80.1 to 146.142.95.254146.142.95.2554,094
103146.142.96.0/20146.142.96.1 to 146.142.111.254146.142.111.2554,094
104146.142.112.0/20146.142.112.1 to 146.142.127.254146.142.127.2554,094
105146.142.128.0/20146.142.128.1 to 146.142.143.254146.142.143.2554,094
106146.142.144.0/20146.142.144.1 to 146.142.159.254146.142.159.2554,094
107146.142.160.0/20146.142.160.1 to 146.142.175.254146.142.175.2554,094
108146.142.176.0/20146.142.176.1 to 146.142.191.254146.142.191.2554,094
109146.142.192.0/20146.142.192.1 to 146.142.207.254146.142.207.2554,094
110146.142.208.0/20146.142.208.1 to 146.142.223.254146.142.223.2554,094
111146.142.224.0/20146.142.224.1 to 146.142.239.254146.142.239.2554,094
112146.142.240.0/20146.142.240.1 to 146.142.255.254146.142.255.2554,094
113146.143.0.0/20146.143.0.1 to 146.143.15.254146.143.15.2554,094
114146.143.16.0/20146.143.16.1 to 146.143.31.254146.143.31.2554,094
115146.143.32.0/20146.143.32.1 to 146.143.47.254146.143.47.2554,094
116146.143.48.0/20146.143.48.1 to 146.143.63.254146.143.63.2554,094
117146.143.64.0/20146.143.64.1 to 146.143.79.254146.143.79.2554,094
118146.143.80.0/20146.143.80.1 to 146.143.95.254146.143.95.2554,094
119146.143.96.0/20146.143.96.1 to 146.143.111.254146.143.111.2554,094
120146.143.112.0/20146.143.112.1 to 146.143.127.254146.143.127.2554,094
121146.143.128.0/20146.143.128.1 to 146.143.143.254146.143.143.2554,094
122146.143.144.0/20146.143.144.1 to 146.143.159.254146.143.159.2554,094
123146.143.160.0/20146.143.160.1 to 146.143.175.254146.143.175.2554,094
124146.143.176.0/20146.143.176.1 to 146.143.191.254146.143.191.2554,094
125146.143.192.0/20146.143.192.1 to 146.143.207.254146.143.207.2554,094
126146.143.208.0/20146.143.208.1 to 146.143.223.254146.143.223.2554,094
127146.143.224.0/20146.143.224.1 to 146.143.239.254146.143.239.2554,094
128146.143.240.0/20146.143.240.1 to 146.143.255.254146.143.255.2554,094

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.