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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.

Network154.48.0.0/13
Usable hosts524,286
Subnet mask255.248.0.0
Addresses524,288
Network address
154.48.0.0
Broadcast address
154.55.255.255
First usable
154.48.0.1
Last usable
154.55.255.254
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 9A300000 · Integer 2586836992 to 2587361279
Reverse DNS zones
48.154.in-addr.arpa
49.154.in-addr.arpa
50.154.in-addr.arpa
51.154.in-addr.arpa
52.154.in-addr.arpa
53.154.in-addr.arpa
54.154.in-addr.arpa
55.154.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
Address10011010.00110000.00000000.00000000154.48.0.0
Subnet mask11111111.11111000.00000000.00000000255.248.0.0
Network10011010.00110000.00000000.00000000154.48.0.0
Broadcast10011010.00110111.11111111.11111111154.55.255.255
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)

154.48.0.0/13 makes 128 subnets of /20.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1154.48.0.0/20154.48.0.1 to 154.48.15.254154.48.15.2554,094
2154.48.16.0/20154.48.16.1 to 154.48.31.254154.48.31.2554,094
3154.48.32.0/20154.48.32.1 to 154.48.47.254154.48.47.2554,094
4154.48.48.0/20154.48.48.1 to 154.48.63.254154.48.63.2554,094
5154.48.64.0/20154.48.64.1 to 154.48.79.254154.48.79.2554,094
6154.48.80.0/20154.48.80.1 to 154.48.95.254154.48.95.2554,094
7154.48.96.0/20154.48.96.1 to 154.48.111.254154.48.111.2554,094
8154.48.112.0/20154.48.112.1 to 154.48.127.254154.48.127.2554,094
9154.48.128.0/20154.48.128.1 to 154.48.143.254154.48.143.2554,094
10154.48.144.0/20154.48.144.1 to 154.48.159.254154.48.159.2554,094
11154.48.160.0/20154.48.160.1 to 154.48.175.254154.48.175.2554,094
12154.48.176.0/20154.48.176.1 to 154.48.191.254154.48.191.2554,094
13154.48.192.0/20154.48.192.1 to 154.48.207.254154.48.207.2554,094
14154.48.208.0/20154.48.208.1 to 154.48.223.254154.48.223.2554,094
15154.48.224.0/20154.48.224.1 to 154.48.239.254154.48.239.2554,094
16154.48.240.0/20154.48.240.1 to 154.48.255.254154.48.255.2554,094
17154.49.0.0/20154.49.0.1 to 154.49.15.254154.49.15.2554,094
18154.49.16.0/20154.49.16.1 to 154.49.31.254154.49.31.2554,094
19154.49.32.0/20154.49.32.1 to 154.49.47.254154.49.47.2554,094
20154.49.48.0/20154.49.48.1 to 154.49.63.254154.49.63.2554,094
21154.49.64.0/20154.49.64.1 to 154.49.79.254154.49.79.2554,094
22154.49.80.0/20154.49.80.1 to 154.49.95.254154.49.95.2554,094
23154.49.96.0/20154.49.96.1 to 154.49.111.254154.49.111.2554,094
24154.49.112.0/20154.49.112.1 to 154.49.127.254154.49.127.2554,094
25154.49.128.0/20154.49.128.1 to 154.49.143.254154.49.143.2554,094
26154.49.144.0/20154.49.144.1 to 154.49.159.254154.49.159.2554,094
27154.49.160.0/20154.49.160.1 to 154.49.175.254154.49.175.2554,094
28154.49.176.0/20154.49.176.1 to 154.49.191.254154.49.191.2554,094
29154.49.192.0/20154.49.192.1 to 154.49.207.254154.49.207.2554,094
30154.49.208.0/20154.49.208.1 to 154.49.223.254154.49.223.2554,094
31154.49.224.0/20154.49.224.1 to 154.49.239.254154.49.239.2554,094
32154.49.240.0/20154.49.240.1 to 154.49.255.254154.49.255.2554,094
33154.50.0.0/20154.50.0.1 to 154.50.15.254154.50.15.2554,094
34154.50.16.0/20154.50.16.1 to 154.50.31.254154.50.31.2554,094
35154.50.32.0/20154.50.32.1 to 154.50.47.254154.50.47.2554,094
36154.50.48.0/20154.50.48.1 to 154.50.63.254154.50.63.2554,094
37154.50.64.0/20154.50.64.1 to 154.50.79.254154.50.79.2554,094
38154.50.80.0/20154.50.80.1 to 154.50.95.254154.50.95.2554,094
39154.50.96.0/20154.50.96.1 to 154.50.111.254154.50.111.2554,094
40154.50.112.0/20154.50.112.1 to 154.50.127.254154.50.127.2554,094
41154.50.128.0/20154.50.128.1 to 154.50.143.254154.50.143.2554,094
42154.50.144.0/20154.50.144.1 to 154.50.159.254154.50.159.2554,094
43154.50.160.0/20154.50.160.1 to 154.50.175.254154.50.175.2554,094
44154.50.176.0/20154.50.176.1 to 154.50.191.254154.50.191.2554,094
45154.50.192.0/20154.50.192.1 to 154.50.207.254154.50.207.2554,094
46154.50.208.0/20154.50.208.1 to 154.50.223.254154.50.223.2554,094
47154.50.224.0/20154.50.224.1 to 154.50.239.254154.50.239.2554,094
48154.50.240.0/20154.50.240.1 to 154.50.255.254154.50.255.2554,094
49154.51.0.0/20154.51.0.1 to 154.51.15.254154.51.15.2554,094
50154.51.16.0/20154.51.16.1 to 154.51.31.254154.51.31.2554,094
51154.51.32.0/20154.51.32.1 to 154.51.47.254154.51.47.2554,094
52154.51.48.0/20154.51.48.1 to 154.51.63.254154.51.63.2554,094
53154.51.64.0/20154.51.64.1 to 154.51.79.254154.51.79.2554,094
54154.51.80.0/20154.51.80.1 to 154.51.95.254154.51.95.2554,094
55154.51.96.0/20154.51.96.1 to 154.51.111.254154.51.111.2554,094
56154.51.112.0/20154.51.112.1 to 154.51.127.254154.51.127.2554,094
57154.51.128.0/20154.51.128.1 to 154.51.143.254154.51.143.2554,094
58154.51.144.0/20154.51.144.1 to 154.51.159.254154.51.159.2554,094
59154.51.160.0/20154.51.160.1 to 154.51.175.254154.51.175.2554,094
60154.51.176.0/20154.51.176.1 to 154.51.191.254154.51.191.2554,094
61154.51.192.0/20154.51.192.1 to 154.51.207.254154.51.207.2554,094
62154.51.208.0/20154.51.208.1 to 154.51.223.254154.51.223.2554,094
63154.51.224.0/20154.51.224.1 to 154.51.239.254154.51.239.2554,094
64154.51.240.0/20154.51.240.1 to 154.51.255.254154.51.255.2554,094
65154.52.0.0/20154.52.0.1 to 154.52.15.254154.52.15.2554,094
66154.52.16.0/20154.52.16.1 to 154.52.31.254154.52.31.2554,094
67154.52.32.0/20154.52.32.1 to 154.52.47.254154.52.47.2554,094
68154.52.48.0/20154.52.48.1 to 154.52.63.254154.52.63.2554,094
69154.52.64.0/20154.52.64.1 to 154.52.79.254154.52.79.2554,094
70154.52.80.0/20154.52.80.1 to 154.52.95.254154.52.95.2554,094
71154.52.96.0/20154.52.96.1 to 154.52.111.254154.52.111.2554,094
72154.52.112.0/20154.52.112.1 to 154.52.127.254154.52.127.2554,094
73154.52.128.0/20154.52.128.1 to 154.52.143.254154.52.143.2554,094
74154.52.144.0/20154.52.144.1 to 154.52.159.254154.52.159.2554,094
75154.52.160.0/20154.52.160.1 to 154.52.175.254154.52.175.2554,094
76154.52.176.0/20154.52.176.1 to 154.52.191.254154.52.191.2554,094
77154.52.192.0/20154.52.192.1 to 154.52.207.254154.52.207.2554,094
78154.52.208.0/20154.52.208.1 to 154.52.223.254154.52.223.2554,094
79154.52.224.0/20154.52.224.1 to 154.52.239.254154.52.239.2554,094
80154.52.240.0/20154.52.240.1 to 154.52.255.254154.52.255.2554,094
81154.53.0.0/20154.53.0.1 to 154.53.15.254154.53.15.2554,094
82154.53.16.0/20154.53.16.1 to 154.53.31.254154.53.31.2554,094
83154.53.32.0/20154.53.32.1 to 154.53.47.254154.53.47.2554,094
84154.53.48.0/20154.53.48.1 to 154.53.63.254154.53.63.2554,094
85154.53.64.0/20154.53.64.1 to 154.53.79.254154.53.79.2554,094
86154.53.80.0/20154.53.80.1 to 154.53.95.254154.53.95.2554,094
87154.53.96.0/20154.53.96.1 to 154.53.111.254154.53.111.2554,094
88154.53.112.0/20154.53.112.1 to 154.53.127.254154.53.127.2554,094
89154.53.128.0/20154.53.128.1 to 154.53.143.254154.53.143.2554,094
90154.53.144.0/20154.53.144.1 to 154.53.159.254154.53.159.2554,094
91154.53.160.0/20154.53.160.1 to 154.53.175.254154.53.175.2554,094
92154.53.176.0/20154.53.176.1 to 154.53.191.254154.53.191.2554,094
93154.53.192.0/20154.53.192.1 to 154.53.207.254154.53.207.2554,094
94154.53.208.0/20154.53.208.1 to 154.53.223.254154.53.223.2554,094
95154.53.224.0/20154.53.224.1 to 154.53.239.254154.53.239.2554,094
96154.53.240.0/20154.53.240.1 to 154.53.255.254154.53.255.2554,094
97154.54.0.0/20154.54.0.1 to 154.54.15.254154.54.15.2554,094
98154.54.16.0/20154.54.16.1 to 154.54.31.254154.54.31.2554,094
99154.54.32.0/20154.54.32.1 to 154.54.47.254154.54.47.2554,094
100154.54.48.0/20154.54.48.1 to 154.54.63.254154.54.63.2554,094
101154.54.64.0/20154.54.64.1 to 154.54.79.254154.54.79.2554,094
102154.54.80.0/20154.54.80.1 to 154.54.95.254154.54.95.2554,094
103154.54.96.0/20154.54.96.1 to 154.54.111.254154.54.111.2554,094
104154.54.112.0/20154.54.112.1 to 154.54.127.254154.54.127.2554,094
105154.54.128.0/20154.54.128.1 to 154.54.143.254154.54.143.2554,094
106154.54.144.0/20154.54.144.1 to 154.54.159.254154.54.159.2554,094
107154.54.160.0/20154.54.160.1 to 154.54.175.254154.54.175.2554,094
108154.54.176.0/20154.54.176.1 to 154.54.191.254154.54.191.2554,094
109154.54.192.0/20154.54.192.1 to 154.54.207.254154.54.207.2554,094
110154.54.208.0/20154.54.208.1 to 154.54.223.254154.54.223.2554,094
111154.54.224.0/20154.54.224.1 to 154.54.239.254154.54.239.2554,094
112154.54.240.0/20154.54.240.1 to 154.54.255.254154.54.255.2554,094
113154.55.0.0/20154.55.0.1 to 154.55.15.254154.55.15.2554,094
114154.55.16.0/20154.55.16.1 to 154.55.31.254154.55.31.2554,094
115154.55.32.0/20154.55.32.1 to 154.55.47.254154.55.47.2554,094
116154.55.48.0/20154.55.48.1 to 154.55.63.254154.55.63.2554,094
117154.55.64.0/20154.55.64.1 to 154.55.79.254154.55.79.2554,094
118154.55.80.0/20154.55.80.1 to 154.55.95.254154.55.95.2554,094
119154.55.96.0/20154.55.96.1 to 154.55.111.254154.55.111.2554,094
120154.55.112.0/20154.55.112.1 to 154.55.127.254154.55.127.2554,094
121154.55.128.0/20154.55.128.1 to 154.55.143.254154.55.143.2554,094
122154.55.144.0/20154.55.144.1 to 154.55.159.254154.55.159.2554,094
123154.55.160.0/20154.55.160.1 to 154.55.175.254154.55.175.2554,094
124154.55.176.0/20154.55.176.1 to 154.55.191.254154.55.191.2554,094
125154.55.192.0/20154.55.192.1 to 154.55.207.254154.55.207.2554,094
126154.55.208.0/20154.55.208.1 to 154.55.223.254154.55.223.2554,094
127154.55.224.0/20154.55.224.1 to 154.55.239.254154.55.239.2554,094
128154.55.240.0/20154.55.240.1 to 154.55.255.254154.55.255.2554,094

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.