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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.

Network113.46.0.0/18
Usable hosts16,382
Subnet mask255.255.192.0
Addresses16,384
Network address
113.46.0.0
Broadcast address
113.46.63.255
First usable
113.46.0.1
Last usable
113.46.63.254
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
A (default /8)
As numbers
Hex 712E0000 · Integer 1898840064 to 1898856447
Reverse DNS zones
0.46.113.in-addr.arpa
1.46.113.in-addr.arpa
2.46.113.in-addr.arpa
3.46.113.in-addr.arpa
4.46.113.in-addr.arpa
5.46.113.in-addr.arpa
6.46.113.in-addr.arpa
7.46.113.in-addr.arpa
8.46.113.in-addr.arpa
9.46.113.in-addr.arpa
10.46.113.in-addr.arpa
11.46.113.in-addr.arpa
12.46.113.in-addr.arpa
13.46.113.in-addr.arpa
14.46.113.in-addr.arpa
15.46.113.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
Address01110001.00101110.00000000.00000000113.46.0.0
Subnet mask11111111.11111111.11000000.00000000255.255.192.0
Network01110001.00101110.00000000.00000000113.46.0.0
Broadcast01110001.00101110.00111111.11111111113.46.63.255
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)

113.46.0.0/18 makes 128 subnets of /25.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1113.46.0.0/25113.46.0.1 to 113.46.0.126113.46.0.127126
2113.46.0.128/25113.46.0.129 to 113.46.0.254113.46.0.255126
3113.46.1.0/25113.46.1.1 to 113.46.1.126113.46.1.127126
4113.46.1.128/25113.46.1.129 to 113.46.1.254113.46.1.255126
5113.46.2.0/25113.46.2.1 to 113.46.2.126113.46.2.127126
6113.46.2.128/25113.46.2.129 to 113.46.2.254113.46.2.255126
7113.46.3.0/25113.46.3.1 to 113.46.3.126113.46.3.127126
8113.46.3.128/25113.46.3.129 to 113.46.3.254113.46.3.255126
9113.46.4.0/25113.46.4.1 to 113.46.4.126113.46.4.127126
10113.46.4.128/25113.46.4.129 to 113.46.4.254113.46.4.255126
11113.46.5.0/25113.46.5.1 to 113.46.5.126113.46.5.127126
12113.46.5.128/25113.46.5.129 to 113.46.5.254113.46.5.255126
13113.46.6.0/25113.46.6.1 to 113.46.6.126113.46.6.127126
14113.46.6.128/25113.46.6.129 to 113.46.6.254113.46.6.255126
15113.46.7.0/25113.46.7.1 to 113.46.7.126113.46.7.127126
16113.46.7.128/25113.46.7.129 to 113.46.7.254113.46.7.255126
17113.46.8.0/25113.46.8.1 to 113.46.8.126113.46.8.127126
18113.46.8.128/25113.46.8.129 to 113.46.8.254113.46.8.255126
19113.46.9.0/25113.46.9.1 to 113.46.9.126113.46.9.127126
20113.46.9.128/25113.46.9.129 to 113.46.9.254113.46.9.255126
21113.46.10.0/25113.46.10.1 to 113.46.10.126113.46.10.127126
22113.46.10.128/25113.46.10.129 to 113.46.10.254113.46.10.255126
23113.46.11.0/25113.46.11.1 to 113.46.11.126113.46.11.127126
24113.46.11.128/25113.46.11.129 to 113.46.11.254113.46.11.255126
25113.46.12.0/25113.46.12.1 to 113.46.12.126113.46.12.127126
26113.46.12.128/25113.46.12.129 to 113.46.12.254113.46.12.255126
27113.46.13.0/25113.46.13.1 to 113.46.13.126113.46.13.127126
28113.46.13.128/25113.46.13.129 to 113.46.13.254113.46.13.255126
29113.46.14.0/25113.46.14.1 to 113.46.14.126113.46.14.127126
30113.46.14.128/25113.46.14.129 to 113.46.14.254113.46.14.255126
31113.46.15.0/25113.46.15.1 to 113.46.15.126113.46.15.127126
32113.46.15.128/25113.46.15.129 to 113.46.15.254113.46.15.255126
33113.46.16.0/25113.46.16.1 to 113.46.16.126113.46.16.127126
34113.46.16.128/25113.46.16.129 to 113.46.16.254113.46.16.255126
35113.46.17.0/25113.46.17.1 to 113.46.17.126113.46.17.127126
36113.46.17.128/25113.46.17.129 to 113.46.17.254113.46.17.255126
37113.46.18.0/25113.46.18.1 to 113.46.18.126113.46.18.127126
38113.46.18.128/25113.46.18.129 to 113.46.18.254113.46.18.255126
39113.46.19.0/25113.46.19.1 to 113.46.19.126113.46.19.127126
40113.46.19.128/25113.46.19.129 to 113.46.19.254113.46.19.255126
41113.46.20.0/25113.46.20.1 to 113.46.20.126113.46.20.127126
42113.46.20.128/25113.46.20.129 to 113.46.20.254113.46.20.255126
43113.46.21.0/25113.46.21.1 to 113.46.21.126113.46.21.127126
44113.46.21.128/25113.46.21.129 to 113.46.21.254113.46.21.255126
45113.46.22.0/25113.46.22.1 to 113.46.22.126113.46.22.127126
46113.46.22.128/25113.46.22.129 to 113.46.22.254113.46.22.255126
47113.46.23.0/25113.46.23.1 to 113.46.23.126113.46.23.127126
48113.46.23.128/25113.46.23.129 to 113.46.23.254113.46.23.255126
49113.46.24.0/25113.46.24.1 to 113.46.24.126113.46.24.127126
50113.46.24.128/25113.46.24.129 to 113.46.24.254113.46.24.255126
51113.46.25.0/25113.46.25.1 to 113.46.25.126113.46.25.127126
52113.46.25.128/25113.46.25.129 to 113.46.25.254113.46.25.255126
53113.46.26.0/25113.46.26.1 to 113.46.26.126113.46.26.127126
54113.46.26.128/25113.46.26.129 to 113.46.26.254113.46.26.255126
55113.46.27.0/25113.46.27.1 to 113.46.27.126113.46.27.127126
56113.46.27.128/25113.46.27.129 to 113.46.27.254113.46.27.255126
57113.46.28.0/25113.46.28.1 to 113.46.28.126113.46.28.127126
58113.46.28.128/25113.46.28.129 to 113.46.28.254113.46.28.255126
59113.46.29.0/25113.46.29.1 to 113.46.29.126113.46.29.127126
60113.46.29.128/25113.46.29.129 to 113.46.29.254113.46.29.255126
61113.46.30.0/25113.46.30.1 to 113.46.30.126113.46.30.127126
62113.46.30.128/25113.46.30.129 to 113.46.30.254113.46.30.255126
63113.46.31.0/25113.46.31.1 to 113.46.31.126113.46.31.127126
64113.46.31.128/25113.46.31.129 to 113.46.31.254113.46.31.255126
65113.46.32.0/25113.46.32.1 to 113.46.32.126113.46.32.127126
66113.46.32.128/25113.46.32.129 to 113.46.32.254113.46.32.255126
67113.46.33.0/25113.46.33.1 to 113.46.33.126113.46.33.127126
68113.46.33.128/25113.46.33.129 to 113.46.33.254113.46.33.255126
69113.46.34.0/25113.46.34.1 to 113.46.34.126113.46.34.127126
70113.46.34.128/25113.46.34.129 to 113.46.34.254113.46.34.255126
71113.46.35.0/25113.46.35.1 to 113.46.35.126113.46.35.127126
72113.46.35.128/25113.46.35.129 to 113.46.35.254113.46.35.255126
73113.46.36.0/25113.46.36.1 to 113.46.36.126113.46.36.127126
74113.46.36.128/25113.46.36.129 to 113.46.36.254113.46.36.255126
75113.46.37.0/25113.46.37.1 to 113.46.37.126113.46.37.127126
76113.46.37.128/25113.46.37.129 to 113.46.37.254113.46.37.255126
77113.46.38.0/25113.46.38.1 to 113.46.38.126113.46.38.127126
78113.46.38.128/25113.46.38.129 to 113.46.38.254113.46.38.255126
79113.46.39.0/25113.46.39.1 to 113.46.39.126113.46.39.127126
80113.46.39.128/25113.46.39.129 to 113.46.39.254113.46.39.255126
81113.46.40.0/25113.46.40.1 to 113.46.40.126113.46.40.127126
82113.46.40.128/25113.46.40.129 to 113.46.40.254113.46.40.255126
83113.46.41.0/25113.46.41.1 to 113.46.41.126113.46.41.127126
84113.46.41.128/25113.46.41.129 to 113.46.41.254113.46.41.255126
85113.46.42.0/25113.46.42.1 to 113.46.42.126113.46.42.127126
86113.46.42.128/25113.46.42.129 to 113.46.42.254113.46.42.255126
87113.46.43.0/25113.46.43.1 to 113.46.43.126113.46.43.127126
88113.46.43.128/25113.46.43.129 to 113.46.43.254113.46.43.255126
89113.46.44.0/25113.46.44.1 to 113.46.44.126113.46.44.127126
90113.46.44.128/25113.46.44.129 to 113.46.44.254113.46.44.255126
91113.46.45.0/25113.46.45.1 to 113.46.45.126113.46.45.127126
92113.46.45.128/25113.46.45.129 to 113.46.45.254113.46.45.255126
93113.46.46.0/25113.46.46.1 to 113.46.46.126113.46.46.127126
94113.46.46.128/25113.46.46.129 to 113.46.46.254113.46.46.255126
95113.46.47.0/25113.46.47.1 to 113.46.47.126113.46.47.127126
96113.46.47.128/25113.46.47.129 to 113.46.47.254113.46.47.255126
97113.46.48.0/25113.46.48.1 to 113.46.48.126113.46.48.127126
98113.46.48.128/25113.46.48.129 to 113.46.48.254113.46.48.255126
99113.46.49.0/25113.46.49.1 to 113.46.49.126113.46.49.127126
100113.46.49.128/25113.46.49.129 to 113.46.49.254113.46.49.255126
101113.46.50.0/25113.46.50.1 to 113.46.50.126113.46.50.127126
102113.46.50.128/25113.46.50.129 to 113.46.50.254113.46.50.255126
103113.46.51.0/25113.46.51.1 to 113.46.51.126113.46.51.127126
104113.46.51.128/25113.46.51.129 to 113.46.51.254113.46.51.255126
105113.46.52.0/25113.46.52.1 to 113.46.52.126113.46.52.127126
106113.46.52.128/25113.46.52.129 to 113.46.52.254113.46.52.255126
107113.46.53.0/25113.46.53.1 to 113.46.53.126113.46.53.127126
108113.46.53.128/25113.46.53.129 to 113.46.53.254113.46.53.255126
109113.46.54.0/25113.46.54.1 to 113.46.54.126113.46.54.127126
110113.46.54.128/25113.46.54.129 to 113.46.54.254113.46.54.255126
111113.46.55.0/25113.46.55.1 to 113.46.55.126113.46.55.127126
112113.46.55.128/25113.46.55.129 to 113.46.55.254113.46.55.255126
113113.46.56.0/25113.46.56.1 to 113.46.56.126113.46.56.127126
114113.46.56.128/25113.46.56.129 to 113.46.56.254113.46.56.255126
115113.46.57.0/25113.46.57.1 to 113.46.57.126113.46.57.127126
116113.46.57.128/25113.46.57.129 to 113.46.57.254113.46.57.255126
117113.46.58.0/25113.46.58.1 to 113.46.58.126113.46.58.127126
118113.46.58.128/25113.46.58.129 to 113.46.58.254113.46.58.255126
119113.46.59.0/25113.46.59.1 to 113.46.59.126113.46.59.127126
120113.46.59.128/25113.46.59.129 to 113.46.59.254113.46.59.255126
121113.46.60.0/25113.46.60.1 to 113.46.60.126113.46.60.127126
122113.46.60.128/25113.46.60.129 to 113.46.60.254113.46.60.255126
123113.46.61.0/25113.46.61.1 to 113.46.61.126113.46.61.127126
124113.46.61.128/25113.46.61.129 to 113.46.61.254113.46.61.255126
125113.46.62.0/25113.46.62.1 to 113.46.62.126113.46.62.127126
126113.46.62.128/25113.46.62.129 to 113.46.62.254113.46.62.255126
127113.46.63.0/25113.46.63.1 to 113.46.63.126113.46.63.127126
128113.46.63.128/25113.46.63.129 to 113.46.63.254113.46.63.255126

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.