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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.

Network147.0.0.0/8
Usable hosts16,777,214
Subnet mask255.0.0.0
Addresses16,777,216
Network address
147.0.0.0
Broadcast address
147.255.255.255
First usable
147.0.0.1
Last usable
147.255.255.254
Usable hosts
16,777,214 (16,777,216 less the network and broadcast addresses)
Subnet mask
255.0.0.0
Wildcard mask
0.255.255.255 (Cisco ACLs, OSPF)
Prefix length
/8
Type
Public public
Old class
B (default /16)
As numbers
Hex 93000000 · Integer 2466250752 to 2483027967
Reverse DNS zone
147.in-addr.arpa
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address10010011..00000000.00000000.00000000147.0.0.0
Subnet mask11111111..00000000.00000000.00000000255.0.0.0
Network10010011..00000000.00000000.00000000147.0.0.0
Broadcast10010011..11111111.11111111.11111111147.255.255.255
Split into smaller subnets/15
/9 (2)/10 (4)/11 (8)/12 (16)/13 (32)/14 (64)/15 (128)/16 (256)/17 (512)/18 (1,024)/19 (2,048)/20 (4,096)

147.0.0.0/8 makes 128 subnets of /15.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1147.0.0.0/15147.0.0.1 to 147.1.255.254147.1.255.255131,070
2147.2.0.0/15147.2.0.1 to 147.3.255.254147.3.255.255131,070
3147.4.0.0/15147.4.0.1 to 147.5.255.254147.5.255.255131,070
4147.6.0.0/15147.6.0.1 to 147.7.255.254147.7.255.255131,070
5147.8.0.0/15147.8.0.1 to 147.9.255.254147.9.255.255131,070
6147.10.0.0/15147.10.0.1 to 147.11.255.254147.11.255.255131,070
7147.12.0.0/15147.12.0.1 to 147.13.255.254147.13.255.255131,070
8147.14.0.0/15147.14.0.1 to 147.15.255.254147.15.255.255131,070
9147.16.0.0/15147.16.0.1 to 147.17.255.254147.17.255.255131,070
10147.18.0.0/15147.18.0.1 to 147.19.255.254147.19.255.255131,070
11147.20.0.0/15147.20.0.1 to 147.21.255.254147.21.255.255131,070
12147.22.0.0/15147.22.0.1 to 147.23.255.254147.23.255.255131,070
13147.24.0.0/15147.24.0.1 to 147.25.255.254147.25.255.255131,070
14147.26.0.0/15147.26.0.1 to 147.27.255.254147.27.255.255131,070
15147.28.0.0/15147.28.0.1 to 147.29.255.254147.29.255.255131,070
16147.30.0.0/15147.30.0.1 to 147.31.255.254147.31.255.255131,070
17147.32.0.0/15147.32.0.1 to 147.33.255.254147.33.255.255131,070
18147.34.0.0/15147.34.0.1 to 147.35.255.254147.35.255.255131,070
19147.36.0.0/15147.36.0.1 to 147.37.255.254147.37.255.255131,070
20147.38.0.0/15147.38.0.1 to 147.39.255.254147.39.255.255131,070
21147.40.0.0/15147.40.0.1 to 147.41.255.254147.41.255.255131,070
22147.42.0.0/15147.42.0.1 to 147.43.255.254147.43.255.255131,070
23147.44.0.0/15147.44.0.1 to 147.45.255.254147.45.255.255131,070
24147.46.0.0/15147.46.0.1 to 147.47.255.254147.47.255.255131,070
25147.48.0.0/15147.48.0.1 to 147.49.255.254147.49.255.255131,070
26147.50.0.0/15147.50.0.1 to 147.51.255.254147.51.255.255131,070
27147.52.0.0/15147.52.0.1 to 147.53.255.254147.53.255.255131,070
28147.54.0.0/15147.54.0.1 to 147.55.255.254147.55.255.255131,070
29147.56.0.0/15147.56.0.1 to 147.57.255.254147.57.255.255131,070
30147.58.0.0/15147.58.0.1 to 147.59.255.254147.59.255.255131,070
31147.60.0.0/15147.60.0.1 to 147.61.255.254147.61.255.255131,070
32147.62.0.0/15147.62.0.1 to 147.63.255.254147.63.255.255131,070
33147.64.0.0/15147.64.0.1 to 147.65.255.254147.65.255.255131,070
34147.66.0.0/15147.66.0.1 to 147.67.255.254147.67.255.255131,070
35147.68.0.0/15147.68.0.1 to 147.69.255.254147.69.255.255131,070
36147.70.0.0/15147.70.0.1 to 147.71.255.254147.71.255.255131,070
37147.72.0.0/15147.72.0.1 to 147.73.255.254147.73.255.255131,070
38147.74.0.0/15147.74.0.1 to 147.75.255.254147.75.255.255131,070
39147.76.0.0/15147.76.0.1 to 147.77.255.254147.77.255.255131,070
40147.78.0.0/15147.78.0.1 to 147.79.255.254147.79.255.255131,070
41147.80.0.0/15147.80.0.1 to 147.81.255.254147.81.255.255131,070
42147.82.0.0/15147.82.0.1 to 147.83.255.254147.83.255.255131,070
43147.84.0.0/15147.84.0.1 to 147.85.255.254147.85.255.255131,070
44147.86.0.0/15147.86.0.1 to 147.87.255.254147.87.255.255131,070
45147.88.0.0/15147.88.0.1 to 147.89.255.254147.89.255.255131,070
46147.90.0.0/15147.90.0.1 to 147.91.255.254147.91.255.255131,070
47147.92.0.0/15147.92.0.1 to 147.93.255.254147.93.255.255131,070
48147.94.0.0/15147.94.0.1 to 147.95.255.254147.95.255.255131,070
49147.96.0.0/15147.96.0.1 to 147.97.255.254147.97.255.255131,070
50147.98.0.0/15147.98.0.1 to 147.99.255.254147.99.255.255131,070
51147.100.0.0/15147.100.0.1 to 147.101.255.254147.101.255.255131,070
52147.102.0.0/15147.102.0.1 to 147.103.255.254147.103.255.255131,070
53147.104.0.0/15147.104.0.1 to 147.105.255.254147.105.255.255131,070
54147.106.0.0/15147.106.0.1 to 147.107.255.254147.107.255.255131,070
55147.108.0.0/15147.108.0.1 to 147.109.255.254147.109.255.255131,070
56147.110.0.0/15147.110.0.1 to 147.111.255.254147.111.255.255131,070
57147.112.0.0/15147.112.0.1 to 147.113.255.254147.113.255.255131,070
58147.114.0.0/15147.114.0.1 to 147.115.255.254147.115.255.255131,070
59147.116.0.0/15147.116.0.1 to 147.117.255.254147.117.255.255131,070
60147.118.0.0/15147.118.0.1 to 147.119.255.254147.119.255.255131,070
61147.120.0.0/15147.120.0.1 to 147.121.255.254147.121.255.255131,070
62147.122.0.0/15147.122.0.1 to 147.123.255.254147.123.255.255131,070
63147.124.0.0/15147.124.0.1 to 147.125.255.254147.125.255.255131,070
64147.126.0.0/15147.126.0.1 to 147.127.255.254147.127.255.255131,070
65147.128.0.0/15147.128.0.1 to 147.129.255.254147.129.255.255131,070
66147.130.0.0/15147.130.0.1 to 147.131.255.254147.131.255.255131,070
67147.132.0.0/15147.132.0.1 to 147.133.255.254147.133.255.255131,070
68147.134.0.0/15147.134.0.1 to 147.135.255.254147.135.255.255131,070
69147.136.0.0/15147.136.0.1 to 147.137.255.254147.137.255.255131,070
70147.138.0.0/15147.138.0.1 to 147.139.255.254147.139.255.255131,070
71147.140.0.0/15147.140.0.1 to 147.141.255.254147.141.255.255131,070
72147.142.0.0/15147.142.0.1 to 147.143.255.254147.143.255.255131,070
73147.144.0.0/15147.144.0.1 to 147.145.255.254147.145.255.255131,070
74147.146.0.0/15147.146.0.1 to 147.147.255.254147.147.255.255131,070
75147.148.0.0/15147.148.0.1 to 147.149.255.254147.149.255.255131,070
76147.150.0.0/15147.150.0.1 to 147.151.255.254147.151.255.255131,070
77147.152.0.0/15147.152.0.1 to 147.153.255.254147.153.255.255131,070
78147.154.0.0/15147.154.0.1 to 147.155.255.254147.155.255.255131,070
79147.156.0.0/15147.156.0.1 to 147.157.255.254147.157.255.255131,070
80147.158.0.0/15147.158.0.1 to 147.159.255.254147.159.255.255131,070
81147.160.0.0/15147.160.0.1 to 147.161.255.254147.161.255.255131,070
82147.162.0.0/15147.162.0.1 to 147.163.255.254147.163.255.255131,070
83147.164.0.0/15147.164.0.1 to 147.165.255.254147.165.255.255131,070
84147.166.0.0/15147.166.0.1 to 147.167.255.254147.167.255.255131,070
85147.168.0.0/15147.168.0.1 to 147.169.255.254147.169.255.255131,070
86147.170.0.0/15147.170.0.1 to 147.171.255.254147.171.255.255131,070
87147.172.0.0/15147.172.0.1 to 147.173.255.254147.173.255.255131,070
88147.174.0.0/15147.174.0.1 to 147.175.255.254147.175.255.255131,070
89147.176.0.0/15147.176.0.1 to 147.177.255.254147.177.255.255131,070
90147.178.0.0/15147.178.0.1 to 147.179.255.254147.179.255.255131,070
91147.180.0.0/15147.180.0.1 to 147.181.255.254147.181.255.255131,070
92147.182.0.0/15147.182.0.1 to 147.183.255.254147.183.255.255131,070
93147.184.0.0/15147.184.0.1 to 147.185.255.254147.185.255.255131,070
94147.186.0.0/15147.186.0.1 to 147.187.255.254147.187.255.255131,070
95147.188.0.0/15147.188.0.1 to 147.189.255.254147.189.255.255131,070
96147.190.0.0/15147.190.0.1 to 147.191.255.254147.191.255.255131,070
97147.192.0.0/15147.192.0.1 to 147.193.255.254147.193.255.255131,070
98147.194.0.0/15147.194.0.1 to 147.195.255.254147.195.255.255131,070
99147.196.0.0/15147.196.0.1 to 147.197.255.254147.197.255.255131,070
100147.198.0.0/15147.198.0.1 to 147.199.255.254147.199.255.255131,070
101147.200.0.0/15147.200.0.1 to 147.201.255.254147.201.255.255131,070
102147.202.0.0/15147.202.0.1 to 147.203.255.254147.203.255.255131,070
103147.204.0.0/15147.204.0.1 to 147.205.255.254147.205.255.255131,070
104147.206.0.0/15147.206.0.1 to 147.207.255.254147.207.255.255131,070
105147.208.0.0/15147.208.0.1 to 147.209.255.254147.209.255.255131,070
106147.210.0.0/15147.210.0.1 to 147.211.255.254147.211.255.255131,070
107147.212.0.0/15147.212.0.1 to 147.213.255.254147.213.255.255131,070
108147.214.0.0/15147.214.0.1 to 147.215.255.254147.215.255.255131,070
109147.216.0.0/15147.216.0.1 to 147.217.255.254147.217.255.255131,070
110147.218.0.0/15147.218.0.1 to 147.219.255.254147.219.255.255131,070
111147.220.0.0/15147.220.0.1 to 147.221.255.254147.221.255.255131,070
112147.222.0.0/15147.222.0.1 to 147.223.255.254147.223.255.255131,070
113147.224.0.0/15147.224.0.1 to 147.225.255.254147.225.255.255131,070
114147.226.0.0/15147.226.0.1 to 147.227.255.254147.227.255.255131,070
115147.228.0.0/15147.228.0.1 to 147.229.255.254147.229.255.255131,070
116147.230.0.0/15147.230.0.1 to 147.231.255.254147.231.255.255131,070
117147.232.0.0/15147.232.0.1 to 147.233.255.254147.233.255.255131,070
118147.234.0.0/15147.234.0.1 to 147.235.255.254147.235.255.255131,070
119147.236.0.0/15147.236.0.1 to 147.237.255.254147.237.255.255131,070
120147.238.0.0/15147.238.0.1 to 147.239.255.254147.239.255.255131,070
121147.240.0.0/15147.240.0.1 to 147.241.255.254147.241.255.255131,070
122147.242.0.0/15147.242.0.1 to 147.243.255.254147.243.255.255131,070
123147.244.0.0/15147.244.0.1 to 147.245.255.254147.245.255.255131,070
124147.246.0.0/15147.246.0.1 to 147.247.255.254147.247.255.255131,070
125147.248.0.0/15147.248.0.1 to 147.249.255.254147.249.255.255131,070
126147.250.0.0/15147.250.0.1 to 147.251.255.254147.251.255.255131,070
127147.252.0.0/15147.252.0.1 to 147.253.255.254147.253.255.255131,070
128147.254.0.0/15147.254.0.1 to 147.255.255.254147.255.255.255131,070

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.