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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.

Network230.224.0.0/11
Usable hosts2,097,150
Subnet mask255.224.0.0
Addresses2,097,152
Network address
230.224.0.0
Broadcast address
230.255.255.255
First usable
230.224.0.1
Last usable
230.255.255.254
Usable hosts
2,097,150 (2,097,152 less the network and broadcast addresses)
Subnet mask
255.224.0.0
Wildcard mask
0.31.255.255 (Cisco ACLs, OSPF)
Prefix length
/11
Type
Multicast 224.0.0.0/4
One-to-many traffic, such as IPTV and routing protocols
Old class
D (multicast)
As numbers
Hex E6E00000 · Integer 3873439744 to 3875536895
Reverse DNS zones
224.230.in-addr.arpa
225.230.in-addr.arpa
226.230.in-addr.arpa
227.230.in-addr.arpa
228.230.in-addr.arpa
229.230.in-addr.arpa
230.230.in-addr.arpa
231.230.in-addr.arpa
232.230.in-addr.arpa
233.230.in-addr.arpa
234.230.in-addr.arpa
235.230.in-addr.arpa
236.230.in-addr.arpa
237.230.in-addr.arpa
238.230.in-addr.arpa
239.230.in-addr.arpa
and 16 more
/11 is not on a 8-bit boundary, so it takes 32 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address11100110.11100000.00000000.00000000230.224.0.0
Subnet mask11111111.11100000.00000000.00000000255.224.0.0
Network11100110.11100000.00000000.00000000230.224.0.0
Broadcast11100110.11111111.11111111.11111111230.255.255.255
Split into smaller subnets/18
/12 (2)/13 (4)/14 (8)/15 (16)/16 (32)/17 (64)/18 (128)/19 (256)/20 (512)/21 (1,024)/22 (2,048)/23 (4,096)

230.224.0.0/11 makes 128 subnets of /18.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1230.224.0.0/18230.224.0.1 to 230.224.63.254230.224.63.25516,382
2230.224.64.0/18230.224.64.1 to 230.224.127.254230.224.127.25516,382
3230.224.128.0/18230.224.128.1 to 230.224.191.254230.224.191.25516,382
4230.224.192.0/18230.224.192.1 to 230.224.255.254230.224.255.25516,382
5230.225.0.0/18230.225.0.1 to 230.225.63.254230.225.63.25516,382
6230.225.64.0/18230.225.64.1 to 230.225.127.254230.225.127.25516,382
7230.225.128.0/18230.225.128.1 to 230.225.191.254230.225.191.25516,382
8230.225.192.0/18230.225.192.1 to 230.225.255.254230.225.255.25516,382
9230.226.0.0/18230.226.0.1 to 230.226.63.254230.226.63.25516,382
10230.226.64.0/18230.226.64.1 to 230.226.127.254230.226.127.25516,382
11230.226.128.0/18230.226.128.1 to 230.226.191.254230.226.191.25516,382
12230.226.192.0/18230.226.192.1 to 230.226.255.254230.226.255.25516,382
13230.227.0.0/18230.227.0.1 to 230.227.63.254230.227.63.25516,382
14230.227.64.0/18230.227.64.1 to 230.227.127.254230.227.127.25516,382
15230.227.128.0/18230.227.128.1 to 230.227.191.254230.227.191.25516,382
16230.227.192.0/18230.227.192.1 to 230.227.255.254230.227.255.25516,382
17230.228.0.0/18230.228.0.1 to 230.228.63.254230.228.63.25516,382
18230.228.64.0/18230.228.64.1 to 230.228.127.254230.228.127.25516,382
19230.228.128.0/18230.228.128.1 to 230.228.191.254230.228.191.25516,382
20230.228.192.0/18230.228.192.1 to 230.228.255.254230.228.255.25516,382
21230.229.0.0/18230.229.0.1 to 230.229.63.254230.229.63.25516,382
22230.229.64.0/18230.229.64.1 to 230.229.127.254230.229.127.25516,382
23230.229.128.0/18230.229.128.1 to 230.229.191.254230.229.191.25516,382
24230.229.192.0/18230.229.192.1 to 230.229.255.254230.229.255.25516,382
25230.230.0.0/18230.230.0.1 to 230.230.63.254230.230.63.25516,382
26230.230.64.0/18230.230.64.1 to 230.230.127.254230.230.127.25516,382
27230.230.128.0/18230.230.128.1 to 230.230.191.254230.230.191.25516,382
28230.230.192.0/18230.230.192.1 to 230.230.255.254230.230.255.25516,382
29230.231.0.0/18230.231.0.1 to 230.231.63.254230.231.63.25516,382
30230.231.64.0/18230.231.64.1 to 230.231.127.254230.231.127.25516,382
31230.231.128.0/18230.231.128.1 to 230.231.191.254230.231.191.25516,382
32230.231.192.0/18230.231.192.1 to 230.231.255.254230.231.255.25516,382
33230.232.0.0/18230.232.0.1 to 230.232.63.254230.232.63.25516,382
34230.232.64.0/18230.232.64.1 to 230.232.127.254230.232.127.25516,382
35230.232.128.0/18230.232.128.1 to 230.232.191.254230.232.191.25516,382
36230.232.192.0/18230.232.192.1 to 230.232.255.254230.232.255.25516,382
37230.233.0.0/18230.233.0.1 to 230.233.63.254230.233.63.25516,382
38230.233.64.0/18230.233.64.1 to 230.233.127.254230.233.127.25516,382
39230.233.128.0/18230.233.128.1 to 230.233.191.254230.233.191.25516,382
40230.233.192.0/18230.233.192.1 to 230.233.255.254230.233.255.25516,382
41230.234.0.0/18230.234.0.1 to 230.234.63.254230.234.63.25516,382
42230.234.64.0/18230.234.64.1 to 230.234.127.254230.234.127.25516,382
43230.234.128.0/18230.234.128.1 to 230.234.191.254230.234.191.25516,382
44230.234.192.0/18230.234.192.1 to 230.234.255.254230.234.255.25516,382
45230.235.0.0/18230.235.0.1 to 230.235.63.254230.235.63.25516,382
46230.235.64.0/18230.235.64.1 to 230.235.127.254230.235.127.25516,382
47230.235.128.0/18230.235.128.1 to 230.235.191.254230.235.191.25516,382
48230.235.192.0/18230.235.192.1 to 230.235.255.254230.235.255.25516,382
49230.236.0.0/18230.236.0.1 to 230.236.63.254230.236.63.25516,382
50230.236.64.0/18230.236.64.1 to 230.236.127.254230.236.127.25516,382
51230.236.128.0/18230.236.128.1 to 230.236.191.254230.236.191.25516,382
52230.236.192.0/18230.236.192.1 to 230.236.255.254230.236.255.25516,382
53230.237.0.0/18230.237.0.1 to 230.237.63.254230.237.63.25516,382
54230.237.64.0/18230.237.64.1 to 230.237.127.254230.237.127.25516,382
55230.237.128.0/18230.237.128.1 to 230.237.191.254230.237.191.25516,382
56230.237.192.0/18230.237.192.1 to 230.237.255.254230.237.255.25516,382
57230.238.0.0/18230.238.0.1 to 230.238.63.254230.238.63.25516,382
58230.238.64.0/18230.238.64.1 to 230.238.127.254230.238.127.25516,382
59230.238.128.0/18230.238.128.1 to 230.238.191.254230.238.191.25516,382
60230.238.192.0/18230.238.192.1 to 230.238.255.254230.238.255.25516,382
61230.239.0.0/18230.239.0.1 to 230.239.63.254230.239.63.25516,382
62230.239.64.0/18230.239.64.1 to 230.239.127.254230.239.127.25516,382
63230.239.128.0/18230.239.128.1 to 230.239.191.254230.239.191.25516,382
64230.239.192.0/18230.239.192.1 to 230.239.255.254230.239.255.25516,382
65230.240.0.0/18230.240.0.1 to 230.240.63.254230.240.63.25516,382
66230.240.64.0/18230.240.64.1 to 230.240.127.254230.240.127.25516,382
67230.240.128.0/18230.240.128.1 to 230.240.191.254230.240.191.25516,382
68230.240.192.0/18230.240.192.1 to 230.240.255.254230.240.255.25516,382
69230.241.0.0/18230.241.0.1 to 230.241.63.254230.241.63.25516,382
70230.241.64.0/18230.241.64.1 to 230.241.127.254230.241.127.25516,382
71230.241.128.0/18230.241.128.1 to 230.241.191.254230.241.191.25516,382
72230.241.192.0/18230.241.192.1 to 230.241.255.254230.241.255.25516,382
73230.242.0.0/18230.242.0.1 to 230.242.63.254230.242.63.25516,382
74230.242.64.0/18230.242.64.1 to 230.242.127.254230.242.127.25516,382
75230.242.128.0/18230.242.128.1 to 230.242.191.254230.242.191.25516,382
76230.242.192.0/18230.242.192.1 to 230.242.255.254230.242.255.25516,382
77230.243.0.0/18230.243.0.1 to 230.243.63.254230.243.63.25516,382
78230.243.64.0/18230.243.64.1 to 230.243.127.254230.243.127.25516,382
79230.243.128.0/18230.243.128.1 to 230.243.191.254230.243.191.25516,382
80230.243.192.0/18230.243.192.1 to 230.243.255.254230.243.255.25516,382
81230.244.0.0/18230.244.0.1 to 230.244.63.254230.244.63.25516,382
82230.244.64.0/18230.244.64.1 to 230.244.127.254230.244.127.25516,382
83230.244.128.0/18230.244.128.1 to 230.244.191.254230.244.191.25516,382
84230.244.192.0/18230.244.192.1 to 230.244.255.254230.244.255.25516,382
85230.245.0.0/18230.245.0.1 to 230.245.63.254230.245.63.25516,382
86230.245.64.0/18230.245.64.1 to 230.245.127.254230.245.127.25516,382
87230.245.128.0/18230.245.128.1 to 230.245.191.254230.245.191.25516,382
88230.245.192.0/18230.245.192.1 to 230.245.255.254230.245.255.25516,382
89230.246.0.0/18230.246.0.1 to 230.246.63.254230.246.63.25516,382
90230.246.64.0/18230.246.64.1 to 230.246.127.254230.246.127.25516,382
91230.246.128.0/18230.246.128.1 to 230.246.191.254230.246.191.25516,382
92230.246.192.0/18230.246.192.1 to 230.246.255.254230.246.255.25516,382
93230.247.0.0/18230.247.0.1 to 230.247.63.254230.247.63.25516,382
94230.247.64.0/18230.247.64.1 to 230.247.127.254230.247.127.25516,382
95230.247.128.0/18230.247.128.1 to 230.247.191.254230.247.191.25516,382
96230.247.192.0/18230.247.192.1 to 230.247.255.254230.247.255.25516,382
97230.248.0.0/18230.248.0.1 to 230.248.63.254230.248.63.25516,382
98230.248.64.0/18230.248.64.1 to 230.248.127.254230.248.127.25516,382
99230.248.128.0/18230.248.128.1 to 230.248.191.254230.248.191.25516,382
100230.248.192.0/18230.248.192.1 to 230.248.255.254230.248.255.25516,382
101230.249.0.0/18230.249.0.1 to 230.249.63.254230.249.63.25516,382
102230.249.64.0/18230.249.64.1 to 230.249.127.254230.249.127.25516,382
103230.249.128.0/18230.249.128.1 to 230.249.191.254230.249.191.25516,382
104230.249.192.0/18230.249.192.1 to 230.249.255.254230.249.255.25516,382
105230.250.0.0/18230.250.0.1 to 230.250.63.254230.250.63.25516,382
106230.250.64.0/18230.250.64.1 to 230.250.127.254230.250.127.25516,382
107230.250.128.0/18230.250.128.1 to 230.250.191.254230.250.191.25516,382
108230.250.192.0/18230.250.192.1 to 230.250.255.254230.250.255.25516,382
109230.251.0.0/18230.251.0.1 to 230.251.63.254230.251.63.25516,382
110230.251.64.0/18230.251.64.1 to 230.251.127.254230.251.127.25516,382
111230.251.128.0/18230.251.128.1 to 230.251.191.254230.251.191.25516,382
112230.251.192.0/18230.251.192.1 to 230.251.255.254230.251.255.25516,382
113230.252.0.0/18230.252.0.1 to 230.252.63.254230.252.63.25516,382
114230.252.64.0/18230.252.64.1 to 230.252.127.254230.252.127.25516,382
115230.252.128.0/18230.252.128.1 to 230.252.191.254230.252.191.25516,382
116230.252.192.0/18230.252.192.1 to 230.252.255.254230.252.255.25516,382
117230.253.0.0/18230.253.0.1 to 230.253.63.254230.253.63.25516,382
118230.253.64.0/18230.253.64.1 to 230.253.127.254230.253.127.25516,382
119230.253.128.0/18230.253.128.1 to 230.253.191.254230.253.191.25516,382
120230.253.192.0/18230.253.192.1 to 230.253.255.254230.253.255.25516,382
121230.254.0.0/18230.254.0.1 to 230.254.63.254230.254.63.25516,382
122230.254.64.0/18230.254.64.1 to 230.254.127.254230.254.127.25516,382
123230.254.128.0/18230.254.128.1 to 230.254.191.254230.254.191.25516,382
124230.254.192.0/18230.254.192.1 to 230.254.255.254230.254.255.25516,382
125230.255.0.0/18230.255.0.1 to 230.255.63.254230.255.63.25516,382
126230.255.64.0/18230.255.64.1 to 230.255.127.254230.255.127.25516,382
127230.255.128.0/18230.255.128.1 to 230.255.191.254230.255.191.25516,382
128230.255.192.0/18230.255.192.1 to 230.255.255.254230.255.255.25516,382

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.