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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.

Network113.2.0.0/15
Usable hosts131,070
Subnet mask255.254.0.0
Addresses131,072
Network address
113.2.0.0
Broadcast address
113.3.255.255
First usable
113.2.0.1
Last usable
113.3.255.254
Usable hosts
131,070 (131,072 less the network and broadcast addresses)
Subnet mask
255.254.0.0
Wildcard mask
0.1.255.255 (Cisco ACLs, OSPF)
Prefix length
/15
Type
Public public
Old class
A (default /8)
As numbers
Hex 71020000 · Integer 1895956480 to 1896087551
Reverse DNS zones
2.113.in-addr.arpa
3.113.in-addr.arpa
/15 is not on a 8-bit boundary, so it takes 2 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address01110001.00000010.00000000.00000000113.2.0.0
Subnet mask11111111.11111110.00000000.00000000255.254.0.0
Network01110001.00000010.00000000.00000000113.2.0.0
Broadcast01110001.00000011.11111111.11111111113.3.255.255
Split into smaller subnets/22
/16 (2)/17 (4)/18 (8)/19 (16)/20 (32)/21 (64)/22 (128)/23 (256)/24 (512)/25 (1,024)/26 (2,048)/27 (4,096)

113.2.0.0/15 makes 128 subnets of /22.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1113.2.0.0/22113.2.0.1 to 113.2.3.254113.2.3.2551,022
2113.2.4.0/22113.2.4.1 to 113.2.7.254113.2.7.2551,022
3113.2.8.0/22113.2.8.1 to 113.2.11.254113.2.11.2551,022
4113.2.12.0/22113.2.12.1 to 113.2.15.254113.2.15.2551,022
5113.2.16.0/22113.2.16.1 to 113.2.19.254113.2.19.2551,022
6113.2.20.0/22113.2.20.1 to 113.2.23.254113.2.23.2551,022
7113.2.24.0/22113.2.24.1 to 113.2.27.254113.2.27.2551,022
8113.2.28.0/22113.2.28.1 to 113.2.31.254113.2.31.2551,022
9113.2.32.0/22113.2.32.1 to 113.2.35.254113.2.35.2551,022
10113.2.36.0/22113.2.36.1 to 113.2.39.254113.2.39.2551,022
11113.2.40.0/22113.2.40.1 to 113.2.43.254113.2.43.2551,022
12113.2.44.0/22113.2.44.1 to 113.2.47.254113.2.47.2551,022
13113.2.48.0/22113.2.48.1 to 113.2.51.254113.2.51.2551,022
14113.2.52.0/22113.2.52.1 to 113.2.55.254113.2.55.2551,022
15113.2.56.0/22113.2.56.1 to 113.2.59.254113.2.59.2551,022
16113.2.60.0/22113.2.60.1 to 113.2.63.254113.2.63.2551,022
17113.2.64.0/22113.2.64.1 to 113.2.67.254113.2.67.2551,022
18113.2.68.0/22113.2.68.1 to 113.2.71.254113.2.71.2551,022
19113.2.72.0/22113.2.72.1 to 113.2.75.254113.2.75.2551,022
20113.2.76.0/22113.2.76.1 to 113.2.79.254113.2.79.2551,022
21113.2.80.0/22113.2.80.1 to 113.2.83.254113.2.83.2551,022
22113.2.84.0/22113.2.84.1 to 113.2.87.254113.2.87.2551,022
23113.2.88.0/22113.2.88.1 to 113.2.91.254113.2.91.2551,022
24113.2.92.0/22113.2.92.1 to 113.2.95.254113.2.95.2551,022
25113.2.96.0/22113.2.96.1 to 113.2.99.254113.2.99.2551,022
26113.2.100.0/22113.2.100.1 to 113.2.103.254113.2.103.2551,022
27113.2.104.0/22113.2.104.1 to 113.2.107.254113.2.107.2551,022
28113.2.108.0/22113.2.108.1 to 113.2.111.254113.2.111.2551,022
29113.2.112.0/22113.2.112.1 to 113.2.115.254113.2.115.2551,022
30113.2.116.0/22113.2.116.1 to 113.2.119.254113.2.119.2551,022
31113.2.120.0/22113.2.120.1 to 113.2.123.254113.2.123.2551,022
32113.2.124.0/22113.2.124.1 to 113.2.127.254113.2.127.2551,022
33113.2.128.0/22113.2.128.1 to 113.2.131.254113.2.131.2551,022
34113.2.132.0/22113.2.132.1 to 113.2.135.254113.2.135.2551,022
35113.2.136.0/22113.2.136.1 to 113.2.139.254113.2.139.2551,022
36113.2.140.0/22113.2.140.1 to 113.2.143.254113.2.143.2551,022
37113.2.144.0/22113.2.144.1 to 113.2.147.254113.2.147.2551,022
38113.2.148.0/22113.2.148.1 to 113.2.151.254113.2.151.2551,022
39113.2.152.0/22113.2.152.1 to 113.2.155.254113.2.155.2551,022
40113.2.156.0/22113.2.156.1 to 113.2.159.254113.2.159.2551,022
41113.2.160.0/22113.2.160.1 to 113.2.163.254113.2.163.2551,022
42113.2.164.0/22113.2.164.1 to 113.2.167.254113.2.167.2551,022
43113.2.168.0/22113.2.168.1 to 113.2.171.254113.2.171.2551,022
44113.2.172.0/22113.2.172.1 to 113.2.175.254113.2.175.2551,022
45113.2.176.0/22113.2.176.1 to 113.2.179.254113.2.179.2551,022
46113.2.180.0/22113.2.180.1 to 113.2.183.254113.2.183.2551,022
47113.2.184.0/22113.2.184.1 to 113.2.187.254113.2.187.2551,022
48113.2.188.0/22113.2.188.1 to 113.2.191.254113.2.191.2551,022
49113.2.192.0/22113.2.192.1 to 113.2.195.254113.2.195.2551,022
50113.2.196.0/22113.2.196.1 to 113.2.199.254113.2.199.2551,022
51113.2.200.0/22113.2.200.1 to 113.2.203.254113.2.203.2551,022
52113.2.204.0/22113.2.204.1 to 113.2.207.254113.2.207.2551,022
53113.2.208.0/22113.2.208.1 to 113.2.211.254113.2.211.2551,022
54113.2.212.0/22113.2.212.1 to 113.2.215.254113.2.215.2551,022
55113.2.216.0/22113.2.216.1 to 113.2.219.254113.2.219.2551,022
56113.2.220.0/22113.2.220.1 to 113.2.223.254113.2.223.2551,022
57113.2.224.0/22113.2.224.1 to 113.2.227.254113.2.227.2551,022
58113.2.228.0/22113.2.228.1 to 113.2.231.254113.2.231.2551,022
59113.2.232.0/22113.2.232.1 to 113.2.235.254113.2.235.2551,022
60113.2.236.0/22113.2.236.1 to 113.2.239.254113.2.239.2551,022
61113.2.240.0/22113.2.240.1 to 113.2.243.254113.2.243.2551,022
62113.2.244.0/22113.2.244.1 to 113.2.247.254113.2.247.2551,022
63113.2.248.0/22113.2.248.1 to 113.2.251.254113.2.251.2551,022
64113.2.252.0/22113.2.252.1 to 113.2.255.254113.2.255.2551,022
65113.3.0.0/22113.3.0.1 to 113.3.3.254113.3.3.2551,022
66113.3.4.0/22113.3.4.1 to 113.3.7.254113.3.7.2551,022
67113.3.8.0/22113.3.8.1 to 113.3.11.254113.3.11.2551,022
68113.3.12.0/22113.3.12.1 to 113.3.15.254113.3.15.2551,022
69113.3.16.0/22113.3.16.1 to 113.3.19.254113.3.19.2551,022
70113.3.20.0/22113.3.20.1 to 113.3.23.254113.3.23.2551,022
71113.3.24.0/22113.3.24.1 to 113.3.27.254113.3.27.2551,022
72113.3.28.0/22113.3.28.1 to 113.3.31.254113.3.31.2551,022
73113.3.32.0/22113.3.32.1 to 113.3.35.254113.3.35.2551,022
74113.3.36.0/22113.3.36.1 to 113.3.39.254113.3.39.2551,022
75113.3.40.0/22113.3.40.1 to 113.3.43.254113.3.43.2551,022
76113.3.44.0/22113.3.44.1 to 113.3.47.254113.3.47.2551,022
77113.3.48.0/22113.3.48.1 to 113.3.51.254113.3.51.2551,022
78113.3.52.0/22113.3.52.1 to 113.3.55.254113.3.55.2551,022
79113.3.56.0/22113.3.56.1 to 113.3.59.254113.3.59.2551,022
80113.3.60.0/22113.3.60.1 to 113.3.63.254113.3.63.2551,022
81113.3.64.0/22113.3.64.1 to 113.3.67.254113.3.67.2551,022
82113.3.68.0/22113.3.68.1 to 113.3.71.254113.3.71.2551,022
83113.3.72.0/22113.3.72.1 to 113.3.75.254113.3.75.2551,022
84113.3.76.0/22113.3.76.1 to 113.3.79.254113.3.79.2551,022
85113.3.80.0/22113.3.80.1 to 113.3.83.254113.3.83.2551,022
86113.3.84.0/22113.3.84.1 to 113.3.87.254113.3.87.2551,022
87113.3.88.0/22113.3.88.1 to 113.3.91.254113.3.91.2551,022
88113.3.92.0/22113.3.92.1 to 113.3.95.254113.3.95.2551,022
89113.3.96.0/22113.3.96.1 to 113.3.99.254113.3.99.2551,022
90113.3.100.0/22113.3.100.1 to 113.3.103.254113.3.103.2551,022
91113.3.104.0/22113.3.104.1 to 113.3.107.254113.3.107.2551,022
92113.3.108.0/22113.3.108.1 to 113.3.111.254113.3.111.2551,022
93113.3.112.0/22113.3.112.1 to 113.3.115.254113.3.115.2551,022
94113.3.116.0/22113.3.116.1 to 113.3.119.254113.3.119.2551,022
95113.3.120.0/22113.3.120.1 to 113.3.123.254113.3.123.2551,022
96113.3.124.0/22113.3.124.1 to 113.3.127.254113.3.127.2551,022
97113.3.128.0/22113.3.128.1 to 113.3.131.254113.3.131.2551,022
98113.3.132.0/22113.3.132.1 to 113.3.135.254113.3.135.2551,022
99113.3.136.0/22113.3.136.1 to 113.3.139.254113.3.139.2551,022
100113.3.140.0/22113.3.140.1 to 113.3.143.254113.3.143.2551,022
101113.3.144.0/22113.3.144.1 to 113.3.147.254113.3.147.2551,022
102113.3.148.0/22113.3.148.1 to 113.3.151.254113.3.151.2551,022
103113.3.152.0/22113.3.152.1 to 113.3.155.254113.3.155.2551,022
104113.3.156.0/22113.3.156.1 to 113.3.159.254113.3.159.2551,022
105113.3.160.0/22113.3.160.1 to 113.3.163.254113.3.163.2551,022
106113.3.164.0/22113.3.164.1 to 113.3.167.254113.3.167.2551,022
107113.3.168.0/22113.3.168.1 to 113.3.171.254113.3.171.2551,022
108113.3.172.0/22113.3.172.1 to 113.3.175.254113.3.175.2551,022
109113.3.176.0/22113.3.176.1 to 113.3.179.254113.3.179.2551,022
110113.3.180.0/22113.3.180.1 to 113.3.183.254113.3.183.2551,022
111113.3.184.0/22113.3.184.1 to 113.3.187.254113.3.187.2551,022
112113.3.188.0/22113.3.188.1 to 113.3.191.254113.3.191.2551,022
113113.3.192.0/22113.3.192.1 to 113.3.195.254113.3.195.2551,022
114113.3.196.0/22113.3.196.1 to 113.3.199.254113.3.199.2551,022
115113.3.200.0/22113.3.200.1 to 113.3.203.254113.3.203.2551,022
116113.3.204.0/22113.3.204.1 to 113.3.207.254113.3.207.2551,022
117113.3.208.0/22113.3.208.1 to 113.3.211.254113.3.211.2551,022
118113.3.212.0/22113.3.212.1 to 113.3.215.254113.3.215.2551,022
119113.3.216.0/22113.3.216.1 to 113.3.219.254113.3.219.2551,022
120113.3.220.0/22113.3.220.1 to 113.3.223.254113.3.223.2551,022
121113.3.224.0/22113.3.224.1 to 113.3.227.254113.3.227.2551,022
122113.3.228.0/22113.3.228.1 to 113.3.231.254113.3.231.2551,022
123113.3.232.0/22113.3.232.1 to 113.3.235.254113.3.235.2551,022
124113.3.236.0/22113.3.236.1 to 113.3.239.254113.3.239.2551,022
125113.3.240.0/22113.3.240.1 to 113.3.243.254113.3.243.2551,022
126113.3.244.0/22113.3.244.1 to 113.3.247.254113.3.247.2551,022
127113.3.248.0/22113.3.248.1 to 113.3.251.254113.3.251.2551,022
128113.3.252.0/22113.3.252.1 to 113.3.255.254113.3.255.2551,022

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.