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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.

Network242.232.96.0/22
Usable hosts1,022
Subnet mask255.255.252.0
Addresses1,024
Network address
242.232.96.0
Broadcast address
242.232.99.255
First usable
242.232.96.1
Last usable
242.232.99.254
Usable hosts
1,022 (1,024 less the network and broadcast addresses)
Subnet mask
255.255.252.0
Wildcard mask
0.0.3.255 (Cisco ACLs, OSPF)
Prefix length
/22
Type
Reserved 240.0.0.0/4
Future use; not usable on most systems
Old class
E (reserved)
As numbers
Hex F2E86000 · Integer 4075315200 to 4075316223
Reverse DNS zones
96.232.242.in-addr.arpa
97.232.242.in-addr.arpa
98.232.242.in-addr.arpa
99.232.242.in-addr.arpa
/22 is not on a 8-bit boundary, so it takes 4 /24 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address11110010.11101000.01100000.00000000242.232.96.0
Subnet mask11111111.11111111.11111100.00000000255.255.252.0
Network11110010.11101000.01100000.00000000242.232.96.0
Broadcast11110010.11101000.01100011.11111111242.232.99.255
Split into smaller subnets/29
/23 (2)/24 (4)/25 (8)/26 (16)/27 (32)/28 (64)/29 (128)/30 (256)/31 (512)/32 (1,024)

242.232.96.0/22 makes 128 subnets of /29.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1242.232.96.0/29242.232.96.1 to 242.232.96.6242.232.96.76
2242.232.96.8/29242.232.96.9 to 242.232.96.14242.232.96.156
3242.232.96.16/29242.232.96.17 to 242.232.96.22242.232.96.236
4242.232.96.24/29242.232.96.25 to 242.232.96.30242.232.96.316
5242.232.96.32/29242.232.96.33 to 242.232.96.38242.232.96.396
6242.232.96.40/29242.232.96.41 to 242.232.96.46242.232.96.476
7242.232.96.48/29242.232.96.49 to 242.232.96.54242.232.96.556
8242.232.96.56/29242.232.96.57 to 242.232.96.62242.232.96.636
9242.232.96.64/29242.232.96.65 to 242.232.96.70242.232.96.716
10242.232.96.72/29242.232.96.73 to 242.232.96.78242.232.96.796
11242.232.96.80/29242.232.96.81 to 242.232.96.86242.232.96.876
12242.232.96.88/29242.232.96.89 to 242.232.96.94242.232.96.956
13242.232.96.96/29242.232.96.97 to 242.232.96.102242.232.96.1036
14242.232.96.104/29242.232.96.105 to 242.232.96.110242.232.96.1116
15242.232.96.112/29242.232.96.113 to 242.232.96.118242.232.96.1196
16242.232.96.120/29242.232.96.121 to 242.232.96.126242.232.96.1276
17242.232.96.128/29242.232.96.129 to 242.232.96.134242.232.96.1356
18242.232.96.136/29242.232.96.137 to 242.232.96.142242.232.96.1436
19242.232.96.144/29242.232.96.145 to 242.232.96.150242.232.96.1516
20242.232.96.152/29242.232.96.153 to 242.232.96.158242.232.96.1596
21242.232.96.160/29242.232.96.161 to 242.232.96.166242.232.96.1676
22242.232.96.168/29242.232.96.169 to 242.232.96.174242.232.96.1756
23242.232.96.176/29242.232.96.177 to 242.232.96.182242.232.96.1836
24242.232.96.184/29242.232.96.185 to 242.232.96.190242.232.96.1916
25242.232.96.192/29242.232.96.193 to 242.232.96.198242.232.96.1996
26242.232.96.200/29242.232.96.201 to 242.232.96.206242.232.96.2076
27242.232.96.208/29242.232.96.209 to 242.232.96.214242.232.96.2156
28242.232.96.216/29242.232.96.217 to 242.232.96.222242.232.96.2236
29242.232.96.224/29242.232.96.225 to 242.232.96.230242.232.96.2316
30242.232.96.232/29242.232.96.233 to 242.232.96.238242.232.96.2396
31242.232.96.240/29242.232.96.241 to 242.232.96.246242.232.96.2476
32242.232.96.248/29242.232.96.249 to 242.232.96.254242.232.96.2556
33242.232.97.0/29242.232.97.1 to 242.232.97.6242.232.97.76
34242.232.97.8/29242.232.97.9 to 242.232.97.14242.232.97.156
35242.232.97.16/29242.232.97.17 to 242.232.97.22242.232.97.236
36242.232.97.24/29242.232.97.25 to 242.232.97.30242.232.97.316
37242.232.97.32/29242.232.97.33 to 242.232.97.38242.232.97.396
38242.232.97.40/29242.232.97.41 to 242.232.97.46242.232.97.476
39242.232.97.48/29242.232.97.49 to 242.232.97.54242.232.97.556
40242.232.97.56/29242.232.97.57 to 242.232.97.62242.232.97.636
41242.232.97.64/29242.232.97.65 to 242.232.97.70242.232.97.716
42242.232.97.72/29242.232.97.73 to 242.232.97.78242.232.97.796
43242.232.97.80/29242.232.97.81 to 242.232.97.86242.232.97.876
44242.232.97.88/29242.232.97.89 to 242.232.97.94242.232.97.956
45242.232.97.96/29242.232.97.97 to 242.232.97.102242.232.97.1036
46242.232.97.104/29242.232.97.105 to 242.232.97.110242.232.97.1116
47242.232.97.112/29242.232.97.113 to 242.232.97.118242.232.97.1196
48242.232.97.120/29242.232.97.121 to 242.232.97.126242.232.97.1276
49242.232.97.128/29242.232.97.129 to 242.232.97.134242.232.97.1356
50242.232.97.136/29242.232.97.137 to 242.232.97.142242.232.97.1436
51242.232.97.144/29242.232.97.145 to 242.232.97.150242.232.97.1516
52242.232.97.152/29242.232.97.153 to 242.232.97.158242.232.97.1596
53242.232.97.160/29242.232.97.161 to 242.232.97.166242.232.97.1676
54242.232.97.168/29242.232.97.169 to 242.232.97.174242.232.97.1756
55242.232.97.176/29242.232.97.177 to 242.232.97.182242.232.97.1836
56242.232.97.184/29242.232.97.185 to 242.232.97.190242.232.97.1916
57242.232.97.192/29242.232.97.193 to 242.232.97.198242.232.97.1996
58242.232.97.200/29242.232.97.201 to 242.232.97.206242.232.97.2076
59242.232.97.208/29242.232.97.209 to 242.232.97.214242.232.97.2156
60242.232.97.216/29242.232.97.217 to 242.232.97.222242.232.97.2236
61242.232.97.224/29242.232.97.225 to 242.232.97.230242.232.97.2316
62242.232.97.232/29242.232.97.233 to 242.232.97.238242.232.97.2396
63242.232.97.240/29242.232.97.241 to 242.232.97.246242.232.97.2476
64242.232.97.248/29242.232.97.249 to 242.232.97.254242.232.97.2556
65242.232.98.0/29242.232.98.1 to 242.232.98.6242.232.98.76
66242.232.98.8/29242.232.98.9 to 242.232.98.14242.232.98.156
67242.232.98.16/29242.232.98.17 to 242.232.98.22242.232.98.236
68242.232.98.24/29242.232.98.25 to 242.232.98.30242.232.98.316
69242.232.98.32/29242.232.98.33 to 242.232.98.38242.232.98.396
70242.232.98.40/29242.232.98.41 to 242.232.98.46242.232.98.476
71242.232.98.48/29242.232.98.49 to 242.232.98.54242.232.98.556
72242.232.98.56/29242.232.98.57 to 242.232.98.62242.232.98.636
73242.232.98.64/29242.232.98.65 to 242.232.98.70242.232.98.716
74242.232.98.72/29242.232.98.73 to 242.232.98.78242.232.98.796
75242.232.98.80/29242.232.98.81 to 242.232.98.86242.232.98.876
76242.232.98.88/29242.232.98.89 to 242.232.98.94242.232.98.956
77242.232.98.96/29242.232.98.97 to 242.232.98.102242.232.98.1036
78242.232.98.104/29242.232.98.105 to 242.232.98.110242.232.98.1116
79242.232.98.112/29242.232.98.113 to 242.232.98.118242.232.98.1196
80242.232.98.120/29242.232.98.121 to 242.232.98.126242.232.98.1276
81242.232.98.128/29242.232.98.129 to 242.232.98.134242.232.98.1356
82242.232.98.136/29242.232.98.137 to 242.232.98.142242.232.98.1436
83242.232.98.144/29242.232.98.145 to 242.232.98.150242.232.98.1516
84242.232.98.152/29242.232.98.153 to 242.232.98.158242.232.98.1596
85242.232.98.160/29242.232.98.161 to 242.232.98.166242.232.98.1676
86242.232.98.168/29242.232.98.169 to 242.232.98.174242.232.98.1756
87242.232.98.176/29242.232.98.177 to 242.232.98.182242.232.98.1836
88242.232.98.184/29242.232.98.185 to 242.232.98.190242.232.98.1916
89242.232.98.192/29242.232.98.193 to 242.232.98.198242.232.98.1996
90242.232.98.200/29242.232.98.201 to 242.232.98.206242.232.98.2076
91242.232.98.208/29242.232.98.209 to 242.232.98.214242.232.98.2156
92242.232.98.216/29242.232.98.217 to 242.232.98.222242.232.98.2236
93242.232.98.224/29242.232.98.225 to 242.232.98.230242.232.98.2316
94242.232.98.232/29242.232.98.233 to 242.232.98.238242.232.98.2396
95242.232.98.240/29242.232.98.241 to 242.232.98.246242.232.98.2476
96242.232.98.248/29242.232.98.249 to 242.232.98.254242.232.98.2556
97242.232.99.0/29242.232.99.1 to 242.232.99.6242.232.99.76
98242.232.99.8/29242.232.99.9 to 242.232.99.14242.232.99.156
99242.232.99.16/29242.232.99.17 to 242.232.99.22242.232.99.236
100242.232.99.24/29242.232.99.25 to 242.232.99.30242.232.99.316
101242.232.99.32/29242.232.99.33 to 242.232.99.38242.232.99.396
102242.232.99.40/29242.232.99.41 to 242.232.99.46242.232.99.476
103242.232.99.48/29242.232.99.49 to 242.232.99.54242.232.99.556
104242.232.99.56/29242.232.99.57 to 242.232.99.62242.232.99.636
105242.232.99.64/29242.232.99.65 to 242.232.99.70242.232.99.716
106242.232.99.72/29242.232.99.73 to 242.232.99.78242.232.99.796
107242.232.99.80/29242.232.99.81 to 242.232.99.86242.232.99.876
108242.232.99.88/29242.232.99.89 to 242.232.99.94242.232.99.956
109242.232.99.96/29242.232.99.97 to 242.232.99.102242.232.99.1036
110242.232.99.104/29242.232.99.105 to 242.232.99.110242.232.99.1116
111242.232.99.112/29242.232.99.113 to 242.232.99.118242.232.99.1196
112242.232.99.120/29242.232.99.121 to 242.232.99.126242.232.99.1276
113242.232.99.128/29242.232.99.129 to 242.232.99.134242.232.99.1356
114242.232.99.136/29242.232.99.137 to 242.232.99.142242.232.99.1436
115242.232.99.144/29242.232.99.145 to 242.232.99.150242.232.99.1516
116242.232.99.152/29242.232.99.153 to 242.232.99.158242.232.99.1596
117242.232.99.160/29242.232.99.161 to 242.232.99.166242.232.99.1676
118242.232.99.168/29242.232.99.169 to 242.232.99.174242.232.99.1756
119242.232.99.176/29242.232.99.177 to 242.232.99.182242.232.99.1836
120242.232.99.184/29242.232.99.185 to 242.232.99.190242.232.99.1916
121242.232.99.192/29242.232.99.193 to 242.232.99.198242.232.99.1996
122242.232.99.200/29242.232.99.201 to 242.232.99.206242.232.99.2076
123242.232.99.208/29242.232.99.209 to 242.232.99.214242.232.99.2156
124242.232.99.216/29242.232.99.217 to 242.232.99.222242.232.99.2236
125242.232.99.224/29242.232.99.225 to 242.232.99.230242.232.99.2316
126242.232.99.232/29242.232.99.233 to 242.232.99.238242.232.99.2396
127242.232.99.240/29242.232.99.241 to 242.232.99.246242.232.99.2476
128242.232.99.248/29242.232.99.249 to 242.232.99.254242.232.99.2556

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.