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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.

Network222.46.0.0/18
Usable hosts16,382
Subnet mask255.255.192.0
Addresses16,384
Network address
222.46.0.0
Broadcast address
222.46.63.255
First usable
222.46.0.1
Last usable
222.46.63.254
Usable hosts
16,382 (16,384 less the network and broadcast addresses)
Subnet mask
255.255.192.0
Wildcard mask
0.0.63.255 (Cisco ACLs, OSPF)
Prefix length
/18
Type
Public public
Old class
C (default /24)
As numbers
Hex DE2E0000 · Integer 3727556608 to 3727572991
Reverse DNS zones
0.46.222.in-addr.arpa
1.46.222.in-addr.arpa
2.46.222.in-addr.arpa
3.46.222.in-addr.arpa
4.46.222.in-addr.arpa
5.46.222.in-addr.arpa
6.46.222.in-addr.arpa
7.46.222.in-addr.arpa
8.46.222.in-addr.arpa
9.46.222.in-addr.arpa
10.46.222.in-addr.arpa
11.46.222.in-addr.arpa
12.46.222.in-addr.arpa
13.46.222.in-addr.arpa
14.46.222.in-addr.arpa
15.46.222.in-addr.arpa
and 48 more
/18 is not on a 8-bit boundary, so it takes 64 /24 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address11011110.00101110.00000000.00000000222.46.0.0
Subnet mask11111111.11111111.11000000.00000000255.255.192.0
Network11011110.00101110.00000000.00000000222.46.0.0
Broadcast11011110.00101110.00111111.11111111222.46.63.255
Split into smaller subnets/25
/19 (2)/20 (4)/21 (8)/22 (16)/23 (32)/24 (64)/25 (128)/26 (256)/27 (512)/28 (1,024)/29 (2,048)/30 (4,096)

222.46.0.0/18 makes 128 subnets of /25.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1222.46.0.0/25222.46.0.1 to 222.46.0.126222.46.0.127126
2222.46.0.128/25222.46.0.129 to 222.46.0.254222.46.0.255126
3222.46.1.0/25222.46.1.1 to 222.46.1.126222.46.1.127126
4222.46.1.128/25222.46.1.129 to 222.46.1.254222.46.1.255126
5222.46.2.0/25222.46.2.1 to 222.46.2.126222.46.2.127126
6222.46.2.128/25222.46.2.129 to 222.46.2.254222.46.2.255126
7222.46.3.0/25222.46.3.1 to 222.46.3.126222.46.3.127126
8222.46.3.128/25222.46.3.129 to 222.46.3.254222.46.3.255126
9222.46.4.0/25222.46.4.1 to 222.46.4.126222.46.4.127126
10222.46.4.128/25222.46.4.129 to 222.46.4.254222.46.4.255126
11222.46.5.0/25222.46.5.1 to 222.46.5.126222.46.5.127126
12222.46.5.128/25222.46.5.129 to 222.46.5.254222.46.5.255126
13222.46.6.0/25222.46.6.1 to 222.46.6.126222.46.6.127126
14222.46.6.128/25222.46.6.129 to 222.46.6.254222.46.6.255126
15222.46.7.0/25222.46.7.1 to 222.46.7.126222.46.7.127126
16222.46.7.128/25222.46.7.129 to 222.46.7.254222.46.7.255126
17222.46.8.0/25222.46.8.1 to 222.46.8.126222.46.8.127126
18222.46.8.128/25222.46.8.129 to 222.46.8.254222.46.8.255126
19222.46.9.0/25222.46.9.1 to 222.46.9.126222.46.9.127126
20222.46.9.128/25222.46.9.129 to 222.46.9.254222.46.9.255126
21222.46.10.0/25222.46.10.1 to 222.46.10.126222.46.10.127126
22222.46.10.128/25222.46.10.129 to 222.46.10.254222.46.10.255126
23222.46.11.0/25222.46.11.1 to 222.46.11.126222.46.11.127126
24222.46.11.128/25222.46.11.129 to 222.46.11.254222.46.11.255126
25222.46.12.0/25222.46.12.1 to 222.46.12.126222.46.12.127126
26222.46.12.128/25222.46.12.129 to 222.46.12.254222.46.12.255126
27222.46.13.0/25222.46.13.1 to 222.46.13.126222.46.13.127126
28222.46.13.128/25222.46.13.129 to 222.46.13.254222.46.13.255126
29222.46.14.0/25222.46.14.1 to 222.46.14.126222.46.14.127126
30222.46.14.128/25222.46.14.129 to 222.46.14.254222.46.14.255126
31222.46.15.0/25222.46.15.1 to 222.46.15.126222.46.15.127126
32222.46.15.128/25222.46.15.129 to 222.46.15.254222.46.15.255126
33222.46.16.0/25222.46.16.1 to 222.46.16.126222.46.16.127126
34222.46.16.128/25222.46.16.129 to 222.46.16.254222.46.16.255126
35222.46.17.0/25222.46.17.1 to 222.46.17.126222.46.17.127126
36222.46.17.128/25222.46.17.129 to 222.46.17.254222.46.17.255126
37222.46.18.0/25222.46.18.1 to 222.46.18.126222.46.18.127126
38222.46.18.128/25222.46.18.129 to 222.46.18.254222.46.18.255126
39222.46.19.0/25222.46.19.1 to 222.46.19.126222.46.19.127126
40222.46.19.128/25222.46.19.129 to 222.46.19.254222.46.19.255126
41222.46.20.0/25222.46.20.1 to 222.46.20.126222.46.20.127126
42222.46.20.128/25222.46.20.129 to 222.46.20.254222.46.20.255126
43222.46.21.0/25222.46.21.1 to 222.46.21.126222.46.21.127126
44222.46.21.128/25222.46.21.129 to 222.46.21.254222.46.21.255126
45222.46.22.0/25222.46.22.1 to 222.46.22.126222.46.22.127126
46222.46.22.128/25222.46.22.129 to 222.46.22.254222.46.22.255126
47222.46.23.0/25222.46.23.1 to 222.46.23.126222.46.23.127126
48222.46.23.128/25222.46.23.129 to 222.46.23.254222.46.23.255126
49222.46.24.0/25222.46.24.1 to 222.46.24.126222.46.24.127126
50222.46.24.128/25222.46.24.129 to 222.46.24.254222.46.24.255126
51222.46.25.0/25222.46.25.1 to 222.46.25.126222.46.25.127126
52222.46.25.128/25222.46.25.129 to 222.46.25.254222.46.25.255126
53222.46.26.0/25222.46.26.1 to 222.46.26.126222.46.26.127126
54222.46.26.128/25222.46.26.129 to 222.46.26.254222.46.26.255126
55222.46.27.0/25222.46.27.1 to 222.46.27.126222.46.27.127126
56222.46.27.128/25222.46.27.129 to 222.46.27.254222.46.27.255126
57222.46.28.0/25222.46.28.1 to 222.46.28.126222.46.28.127126
58222.46.28.128/25222.46.28.129 to 222.46.28.254222.46.28.255126
59222.46.29.0/25222.46.29.1 to 222.46.29.126222.46.29.127126
60222.46.29.128/25222.46.29.129 to 222.46.29.254222.46.29.255126
61222.46.30.0/25222.46.30.1 to 222.46.30.126222.46.30.127126
62222.46.30.128/25222.46.30.129 to 222.46.30.254222.46.30.255126
63222.46.31.0/25222.46.31.1 to 222.46.31.126222.46.31.127126
64222.46.31.128/25222.46.31.129 to 222.46.31.254222.46.31.255126
65222.46.32.0/25222.46.32.1 to 222.46.32.126222.46.32.127126
66222.46.32.128/25222.46.32.129 to 222.46.32.254222.46.32.255126
67222.46.33.0/25222.46.33.1 to 222.46.33.126222.46.33.127126
68222.46.33.128/25222.46.33.129 to 222.46.33.254222.46.33.255126
69222.46.34.0/25222.46.34.1 to 222.46.34.126222.46.34.127126
70222.46.34.128/25222.46.34.129 to 222.46.34.254222.46.34.255126
71222.46.35.0/25222.46.35.1 to 222.46.35.126222.46.35.127126
72222.46.35.128/25222.46.35.129 to 222.46.35.254222.46.35.255126
73222.46.36.0/25222.46.36.1 to 222.46.36.126222.46.36.127126
74222.46.36.128/25222.46.36.129 to 222.46.36.254222.46.36.255126
75222.46.37.0/25222.46.37.1 to 222.46.37.126222.46.37.127126
76222.46.37.128/25222.46.37.129 to 222.46.37.254222.46.37.255126
77222.46.38.0/25222.46.38.1 to 222.46.38.126222.46.38.127126
78222.46.38.128/25222.46.38.129 to 222.46.38.254222.46.38.255126
79222.46.39.0/25222.46.39.1 to 222.46.39.126222.46.39.127126
80222.46.39.128/25222.46.39.129 to 222.46.39.254222.46.39.255126
81222.46.40.0/25222.46.40.1 to 222.46.40.126222.46.40.127126
82222.46.40.128/25222.46.40.129 to 222.46.40.254222.46.40.255126
83222.46.41.0/25222.46.41.1 to 222.46.41.126222.46.41.127126
84222.46.41.128/25222.46.41.129 to 222.46.41.254222.46.41.255126
85222.46.42.0/25222.46.42.1 to 222.46.42.126222.46.42.127126
86222.46.42.128/25222.46.42.129 to 222.46.42.254222.46.42.255126
87222.46.43.0/25222.46.43.1 to 222.46.43.126222.46.43.127126
88222.46.43.128/25222.46.43.129 to 222.46.43.254222.46.43.255126
89222.46.44.0/25222.46.44.1 to 222.46.44.126222.46.44.127126
90222.46.44.128/25222.46.44.129 to 222.46.44.254222.46.44.255126
91222.46.45.0/25222.46.45.1 to 222.46.45.126222.46.45.127126
92222.46.45.128/25222.46.45.129 to 222.46.45.254222.46.45.255126
93222.46.46.0/25222.46.46.1 to 222.46.46.126222.46.46.127126
94222.46.46.128/25222.46.46.129 to 222.46.46.254222.46.46.255126
95222.46.47.0/25222.46.47.1 to 222.46.47.126222.46.47.127126
96222.46.47.128/25222.46.47.129 to 222.46.47.254222.46.47.255126
97222.46.48.0/25222.46.48.1 to 222.46.48.126222.46.48.127126
98222.46.48.128/25222.46.48.129 to 222.46.48.254222.46.48.255126
99222.46.49.0/25222.46.49.1 to 222.46.49.126222.46.49.127126
100222.46.49.128/25222.46.49.129 to 222.46.49.254222.46.49.255126
101222.46.50.0/25222.46.50.1 to 222.46.50.126222.46.50.127126
102222.46.50.128/25222.46.50.129 to 222.46.50.254222.46.50.255126
103222.46.51.0/25222.46.51.1 to 222.46.51.126222.46.51.127126
104222.46.51.128/25222.46.51.129 to 222.46.51.254222.46.51.255126
105222.46.52.0/25222.46.52.1 to 222.46.52.126222.46.52.127126
106222.46.52.128/25222.46.52.129 to 222.46.52.254222.46.52.255126
107222.46.53.0/25222.46.53.1 to 222.46.53.126222.46.53.127126
108222.46.53.128/25222.46.53.129 to 222.46.53.254222.46.53.255126
109222.46.54.0/25222.46.54.1 to 222.46.54.126222.46.54.127126
110222.46.54.128/25222.46.54.129 to 222.46.54.254222.46.54.255126
111222.46.55.0/25222.46.55.1 to 222.46.55.126222.46.55.127126
112222.46.55.128/25222.46.55.129 to 222.46.55.254222.46.55.255126
113222.46.56.0/25222.46.56.1 to 222.46.56.126222.46.56.127126
114222.46.56.128/25222.46.56.129 to 222.46.56.254222.46.56.255126
115222.46.57.0/25222.46.57.1 to 222.46.57.126222.46.57.127126
116222.46.57.128/25222.46.57.129 to 222.46.57.254222.46.57.255126
117222.46.58.0/25222.46.58.1 to 222.46.58.126222.46.58.127126
118222.46.58.128/25222.46.58.129 to 222.46.58.254222.46.58.255126
119222.46.59.0/25222.46.59.1 to 222.46.59.126222.46.59.127126
120222.46.59.128/25222.46.59.129 to 222.46.59.254222.46.59.255126
121222.46.60.0/25222.46.60.1 to 222.46.60.126222.46.60.127126
122222.46.60.128/25222.46.60.129 to 222.46.60.254222.46.60.255126
123222.46.61.0/25222.46.61.1 to 222.46.61.126222.46.61.127126
124222.46.61.128/25222.46.61.129 to 222.46.61.254222.46.61.255126
125222.46.62.0/25222.46.62.1 to 222.46.62.126222.46.62.127126
126222.46.62.128/25222.46.62.129 to 222.46.62.254222.46.62.255126
127222.46.63.0/25222.46.63.1 to 222.46.63.126222.46.63.127126
128222.46.63.128/25222.46.63.129 to 222.46.63.254222.46.63.255126

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.