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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.

Network229.0.0.0/13
Usable hosts524,286
Subnet mask255.248.0.0
Addresses524,288
Network address
229.0.0.0
Broadcast address
229.7.255.255
First usable
229.0.0.1
Last usable
229.7.255.254
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
Multicast 224.0.0.0/4
One-to-many traffic, such as IPTV and routing protocols
Old class
D (multicast)
As numbers
Hex E5000000 · Integer 3841982464 to 3842506751
Reverse DNS zones
0.229.in-addr.arpa
1.229.in-addr.arpa
2.229.in-addr.arpa
3.229.in-addr.arpa
4.229.in-addr.arpa
5.229.in-addr.arpa
6.229.in-addr.arpa
7.229.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
Address11100101.00000000.00000000.00000000229.0.0.0
Subnet mask11111111.11111000.00000000.00000000255.248.0.0
Network11100101.00000000.00000000.00000000229.0.0.0
Broadcast11100101.00000111.11111111.11111111229.7.255.255
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)

229.0.0.0/13 makes 128 subnets of /20.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1229.0.0.0/20229.0.0.1 to 229.0.15.254229.0.15.2554,094
2229.0.16.0/20229.0.16.1 to 229.0.31.254229.0.31.2554,094
3229.0.32.0/20229.0.32.1 to 229.0.47.254229.0.47.2554,094
4229.0.48.0/20229.0.48.1 to 229.0.63.254229.0.63.2554,094
5229.0.64.0/20229.0.64.1 to 229.0.79.254229.0.79.2554,094
6229.0.80.0/20229.0.80.1 to 229.0.95.254229.0.95.2554,094
7229.0.96.0/20229.0.96.1 to 229.0.111.254229.0.111.2554,094
8229.0.112.0/20229.0.112.1 to 229.0.127.254229.0.127.2554,094
9229.0.128.0/20229.0.128.1 to 229.0.143.254229.0.143.2554,094
10229.0.144.0/20229.0.144.1 to 229.0.159.254229.0.159.2554,094
11229.0.160.0/20229.0.160.1 to 229.0.175.254229.0.175.2554,094
12229.0.176.0/20229.0.176.1 to 229.0.191.254229.0.191.2554,094
13229.0.192.0/20229.0.192.1 to 229.0.207.254229.0.207.2554,094
14229.0.208.0/20229.0.208.1 to 229.0.223.254229.0.223.2554,094
15229.0.224.0/20229.0.224.1 to 229.0.239.254229.0.239.2554,094
16229.0.240.0/20229.0.240.1 to 229.0.255.254229.0.255.2554,094
17229.1.0.0/20229.1.0.1 to 229.1.15.254229.1.15.2554,094
18229.1.16.0/20229.1.16.1 to 229.1.31.254229.1.31.2554,094
19229.1.32.0/20229.1.32.1 to 229.1.47.254229.1.47.2554,094
20229.1.48.0/20229.1.48.1 to 229.1.63.254229.1.63.2554,094
21229.1.64.0/20229.1.64.1 to 229.1.79.254229.1.79.2554,094
22229.1.80.0/20229.1.80.1 to 229.1.95.254229.1.95.2554,094
23229.1.96.0/20229.1.96.1 to 229.1.111.254229.1.111.2554,094
24229.1.112.0/20229.1.112.1 to 229.1.127.254229.1.127.2554,094
25229.1.128.0/20229.1.128.1 to 229.1.143.254229.1.143.2554,094
26229.1.144.0/20229.1.144.1 to 229.1.159.254229.1.159.2554,094
27229.1.160.0/20229.1.160.1 to 229.1.175.254229.1.175.2554,094
28229.1.176.0/20229.1.176.1 to 229.1.191.254229.1.191.2554,094
29229.1.192.0/20229.1.192.1 to 229.1.207.254229.1.207.2554,094
30229.1.208.0/20229.1.208.1 to 229.1.223.254229.1.223.2554,094
31229.1.224.0/20229.1.224.1 to 229.1.239.254229.1.239.2554,094
32229.1.240.0/20229.1.240.1 to 229.1.255.254229.1.255.2554,094
33229.2.0.0/20229.2.0.1 to 229.2.15.254229.2.15.2554,094
34229.2.16.0/20229.2.16.1 to 229.2.31.254229.2.31.2554,094
35229.2.32.0/20229.2.32.1 to 229.2.47.254229.2.47.2554,094
36229.2.48.0/20229.2.48.1 to 229.2.63.254229.2.63.2554,094
37229.2.64.0/20229.2.64.1 to 229.2.79.254229.2.79.2554,094
38229.2.80.0/20229.2.80.1 to 229.2.95.254229.2.95.2554,094
39229.2.96.0/20229.2.96.1 to 229.2.111.254229.2.111.2554,094
40229.2.112.0/20229.2.112.1 to 229.2.127.254229.2.127.2554,094
41229.2.128.0/20229.2.128.1 to 229.2.143.254229.2.143.2554,094
42229.2.144.0/20229.2.144.1 to 229.2.159.254229.2.159.2554,094
43229.2.160.0/20229.2.160.1 to 229.2.175.254229.2.175.2554,094
44229.2.176.0/20229.2.176.1 to 229.2.191.254229.2.191.2554,094
45229.2.192.0/20229.2.192.1 to 229.2.207.254229.2.207.2554,094
46229.2.208.0/20229.2.208.1 to 229.2.223.254229.2.223.2554,094
47229.2.224.0/20229.2.224.1 to 229.2.239.254229.2.239.2554,094
48229.2.240.0/20229.2.240.1 to 229.2.255.254229.2.255.2554,094
49229.3.0.0/20229.3.0.1 to 229.3.15.254229.3.15.2554,094
50229.3.16.0/20229.3.16.1 to 229.3.31.254229.3.31.2554,094
51229.3.32.0/20229.3.32.1 to 229.3.47.254229.3.47.2554,094
52229.3.48.0/20229.3.48.1 to 229.3.63.254229.3.63.2554,094
53229.3.64.0/20229.3.64.1 to 229.3.79.254229.3.79.2554,094
54229.3.80.0/20229.3.80.1 to 229.3.95.254229.3.95.2554,094
55229.3.96.0/20229.3.96.1 to 229.3.111.254229.3.111.2554,094
56229.3.112.0/20229.3.112.1 to 229.3.127.254229.3.127.2554,094
57229.3.128.0/20229.3.128.1 to 229.3.143.254229.3.143.2554,094
58229.3.144.0/20229.3.144.1 to 229.3.159.254229.3.159.2554,094
59229.3.160.0/20229.3.160.1 to 229.3.175.254229.3.175.2554,094
60229.3.176.0/20229.3.176.1 to 229.3.191.254229.3.191.2554,094
61229.3.192.0/20229.3.192.1 to 229.3.207.254229.3.207.2554,094
62229.3.208.0/20229.3.208.1 to 229.3.223.254229.3.223.2554,094
63229.3.224.0/20229.3.224.1 to 229.3.239.254229.3.239.2554,094
64229.3.240.0/20229.3.240.1 to 229.3.255.254229.3.255.2554,094
65229.4.0.0/20229.4.0.1 to 229.4.15.254229.4.15.2554,094
66229.4.16.0/20229.4.16.1 to 229.4.31.254229.4.31.2554,094
67229.4.32.0/20229.4.32.1 to 229.4.47.254229.4.47.2554,094
68229.4.48.0/20229.4.48.1 to 229.4.63.254229.4.63.2554,094
69229.4.64.0/20229.4.64.1 to 229.4.79.254229.4.79.2554,094
70229.4.80.0/20229.4.80.1 to 229.4.95.254229.4.95.2554,094
71229.4.96.0/20229.4.96.1 to 229.4.111.254229.4.111.2554,094
72229.4.112.0/20229.4.112.1 to 229.4.127.254229.4.127.2554,094
73229.4.128.0/20229.4.128.1 to 229.4.143.254229.4.143.2554,094
74229.4.144.0/20229.4.144.1 to 229.4.159.254229.4.159.2554,094
75229.4.160.0/20229.4.160.1 to 229.4.175.254229.4.175.2554,094
76229.4.176.0/20229.4.176.1 to 229.4.191.254229.4.191.2554,094
77229.4.192.0/20229.4.192.1 to 229.4.207.254229.4.207.2554,094
78229.4.208.0/20229.4.208.1 to 229.4.223.254229.4.223.2554,094
79229.4.224.0/20229.4.224.1 to 229.4.239.254229.4.239.2554,094
80229.4.240.0/20229.4.240.1 to 229.4.255.254229.4.255.2554,094
81229.5.0.0/20229.5.0.1 to 229.5.15.254229.5.15.2554,094
82229.5.16.0/20229.5.16.1 to 229.5.31.254229.5.31.2554,094
83229.5.32.0/20229.5.32.1 to 229.5.47.254229.5.47.2554,094
84229.5.48.0/20229.5.48.1 to 229.5.63.254229.5.63.2554,094
85229.5.64.0/20229.5.64.1 to 229.5.79.254229.5.79.2554,094
86229.5.80.0/20229.5.80.1 to 229.5.95.254229.5.95.2554,094
87229.5.96.0/20229.5.96.1 to 229.5.111.254229.5.111.2554,094
88229.5.112.0/20229.5.112.1 to 229.5.127.254229.5.127.2554,094
89229.5.128.0/20229.5.128.1 to 229.5.143.254229.5.143.2554,094
90229.5.144.0/20229.5.144.1 to 229.5.159.254229.5.159.2554,094
91229.5.160.0/20229.5.160.1 to 229.5.175.254229.5.175.2554,094
92229.5.176.0/20229.5.176.1 to 229.5.191.254229.5.191.2554,094
93229.5.192.0/20229.5.192.1 to 229.5.207.254229.5.207.2554,094
94229.5.208.0/20229.5.208.1 to 229.5.223.254229.5.223.2554,094
95229.5.224.0/20229.5.224.1 to 229.5.239.254229.5.239.2554,094
96229.5.240.0/20229.5.240.1 to 229.5.255.254229.5.255.2554,094
97229.6.0.0/20229.6.0.1 to 229.6.15.254229.6.15.2554,094
98229.6.16.0/20229.6.16.1 to 229.6.31.254229.6.31.2554,094
99229.6.32.0/20229.6.32.1 to 229.6.47.254229.6.47.2554,094
100229.6.48.0/20229.6.48.1 to 229.6.63.254229.6.63.2554,094
101229.6.64.0/20229.6.64.1 to 229.6.79.254229.6.79.2554,094
102229.6.80.0/20229.6.80.1 to 229.6.95.254229.6.95.2554,094
103229.6.96.0/20229.6.96.1 to 229.6.111.254229.6.111.2554,094
104229.6.112.0/20229.6.112.1 to 229.6.127.254229.6.127.2554,094
105229.6.128.0/20229.6.128.1 to 229.6.143.254229.6.143.2554,094
106229.6.144.0/20229.6.144.1 to 229.6.159.254229.6.159.2554,094
107229.6.160.0/20229.6.160.1 to 229.6.175.254229.6.175.2554,094
108229.6.176.0/20229.6.176.1 to 229.6.191.254229.6.191.2554,094
109229.6.192.0/20229.6.192.1 to 229.6.207.254229.6.207.2554,094
110229.6.208.0/20229.6.208.1 to 229.6.223.254229.6.223.2554,094
111229.6.224.0/20229.6.224.1 to 229.6.239.254229.6.239.2554,094
112229.6.240.0/20229.6.240.1 to 229.6.255.254229.6.255.2554,094
113229.7.0.0/20229.7.0.1 to 229.7.15.254229.7.15.2554,094
114229.7.16.0/20229.7.16.1 to 229.7.31.254229.7.31.2554,094
115229.7.32.0/20229.7.32.1 to 229.7.47.254229.7.47.2554,094
116229.7.48.0/20229.7.48.1 to 229.7.63.254229.7.63.2554,094
117229.7.64.0/20229.7.64.1 to 229.7.79.254229.7.79.2554,094
118229.7.80.0/20229.7.80.1 to 229.7.95.254229.7.95.2554,094
119229.7.96.0/20229.7.96.1 to 229.7.111.254229.7.111.2554,094
120229.7.112.0/20229.7.112.1 to 229.7.127.254229.7.127.2554,094
121229.7.128.0/20229.7.128.1 to 229.7.143.254229.7.143.2554,094
122229.7.144.0/20229.7.144.1 to 229.7.159.254229.7.159.2554,094
123229.7.160.0/20229.7.160.1 to 229.7.175.254229.7.175.2554,094
124229.7.176.0/20229.7.176.1 to 229.7.191.254229.7.191.2554,094
125229.7.192.0/20229.7.192.1 to 229.7.207.254229.7.207.2554,094
126229.7.208.0/20229.7.208.1 to 229.7.223.254229.7.223.2554,094
127229.7.224.0/20229.7.224.1 to 229.7.239.254229.7.239.2554,094
128229.7.240.0/20229.7.240.1 to 229.7.255.254229.7.255.2554,094

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.