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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.

Network246.152.0.0/13
Usable hosts524,286
Subnet mask255.248.0.0
Addresses524,288
Network address
246.152.0.0
Broadcast address
246.159.255.255
First usable
246.152.0.1
Last usable
246.159.255.254
Usable hosts
524,286 (524,288 less the network and broadcast addresses)
Subnet mask
255.248.0.0
Wildcard mask
0.7.255.255 (Cisco ACLs, OSPF)
Prefix length
/13
Type
Reserved 240.0.0.0/4
Future use; not usable on most systems
Old class
E (reserved)
As numbers
Hex F6980000 · Integer 4137156608 to 4137680895
Reverse DNS zones
152.246.in-addr.arpa
153.246.in-addr.arpa
154.246.in-addr.arpa
155.246.in-addr.arpa
156.246.in-addr.arpa
157.246.in-addr.arpa
158.246.in-addr.arpa
159.246.in-addr.arpa
/13 is not on a 8-bit boundary, so it takes 8 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address11110110.10011000.00000000.00000000246.152.0.0
Subnet mask11111111.11111000.00000000.00000000255.248.0.0
Network11110110.10011000.00000000.00000000246.152.0.0
Broadcast11110110.10011111.11111111.11111111246.159.255.255
Split into smaller subnets/20
/14 (2)/15 (4)/16 (8)/17 (16)/18 (32)/19 (64)/20 (128)/21 (256)/22 (512)/23 (1,024)/24 (2,048)/25 (4,096)

246.152.0.0/13 makes 128 subnets of /20.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1246.152.0.0/20246.152.0.1 to 246.152.15.254246.152.15.2554,094
2246.152.16.0/20246.152.16.1 to 246.152.31.254246.152.31.2554,094
3246.152.32.0/20246.152.32.1 to 246.152.47.254246.152.47.2554,094
4246.152.48.0/20246.152.48.1 to 246.152.63.254246.152.63.2554,094
5246.152.64.0/20246.152.64.1 to 246.152.79.254246.152.79.2554,094
6246.152.80.0/20246.152.80.1 to 246.152.95.254246.152.95.2554,094
7246.152.96.0/20246.152.96.1 to 246.152.111.254246.152.111.2554,094
8246.152.112.0/20246.152.112.1 to 246.152.127.254246.152.127.2554,094
9246.152.128.0/20246.152.128.1 to 246.152.143.254246.152.143.2554,094
10246.152.144.0/20246.152.144.1 to 246.152.159.254246.152.159.2554,094
11246.152.160.0/20246.152.160.1 to 246.152.175.254246.152.175.2554,094
12246.152.176.0/20246.152.176.1 to 246.152.191.254246.152.191.2554,094
13246.152.192.0/20246.152.192.1 to 246.152.207.254246.152.207.2554,094
14246.152.208.0/20246.152.208.1 to 246.152.223.254246.152.223.2554,094
15246.152.224.0/20246.152.224.1 to 246.152.239.254246.152.239.2554,094
16246.152.240.0/20246.152.240.1 to 246.152.255.254246.152.255.2554,094
17246.153.0.0/20246.153.0.1 to 246.153.15.254246.153.15.2554,094
18246.153.16.0/20246.153.16.1 to 246.153.31.254246.153.31.2554,094
19246.153.32.0/20246.153.32.1 to 246.153.47.254246.153.47.2554,094
20246.153.48.0/20246.153.48.1 to 246.153.63.254246.153.63.2554,094
21246.153.64.0/20246.153.64.1 to 246.153.79.254246.153.79.2554,094
22246.153.80.0/20246.153.80.1 to 246.153.95.254246.153.95.2554,094
23246.153.96.0/20246.153.96.1 to 246.153.111.254246.153.111.2554,094
24246.153.112.0/20246.153.112.1 to 246.153.127.254246.153.127.2554,094
25246.153.128.0/20246.153.128.1 to 246.153.143.254246.153.143.2554,094
26246.153.144.0/20246.153.144.1 to 246.153.159.254246.153.159.2554,094
27246.153.160.0/20246.153.160.1 to 246.153.175.254246.153.175.2554,094
28246.153.176.0/20246.153.176.1 to 246.153.191.254246.153.191.2554,094
29246.153.192.0/20246.153.192.1 to 246.153.207.254246.153.207.2554,094
30246.153.208.0/20246.153.208.1 to 246.153.223.254246.153.223.2554,094
31246.153.224.0/20246.153.224.1 to 246.153.239.254246.153.239.2554,094
32246.153.240.0/20246.153.240.1 to 246.153.255.254246.153.255.2554,094
33246.154.0.0/20246.154.0.1 to 246.154.15.254246.154.15.2554,094
34246.154.16.0/20246.154.16.1 to 246.154.31.254246.154.31.2554,094
35246.154.32.0/20246.154.32.1 to 246.154.47.254246.154.47.2554,094
36246.154.48.0/20246.154.48.1 to 246.154.63.254246.154.63.2554,094
37246.154.64.0/20246.154.64.1 to 246.154.79.254246.154.79.2554,094
38246.154.80.0/20246.154.80.1 to 246.154.95.254246.154.95.2554,094
39246.154.96.0/20246.154.96.1 to 246.154.111.254246.154.111.2554,094
40246.154.112.0/20246.154.112.1 to 246.154.127.254246.154.127.2554,094
41246.154.128.0/20246.154.128.1 to 246.154.143.254246.154.143.2554,094
42246.154.144.0/20246.154.144.1 to 246.154.159.254246.154.159.2554,094
43246.154.160.0/20246.154.160.1 to 246.154.175.254246.154.175.2554,094
44246.154.176.0/20246.154.176.1 to 246.154.191.254246.154.191.2554,094
45246.154.192.0/20246.154.192.1 to 246.154.207.254246.154.207.2554,094
46246.154.208.0/20246.154.208.1 to 246.154.223.254246.154.223.2554,094
47246.154.224.0/20246.154.224.1 to 246.154.239.254246.154.239.2554,094
48246.154.240.0/20246.154.240.1 to 246.154.255.254246.154.255.2554,094
49246.155.0.0/20246.155.0.1 to 246.155.15.254246.155.15.2554,094
50246.155.16.0/20246.155.16.1 to 246.155.31.254246.155.31.2554,094
51246.155.32.0/20246.155.32.1 to 246.155.47.254246.155.47.2554,094
52246.155.48.0/20246.155.48.1 to 246.155.63.254246.155.63.2554,094
53246.155.64.0/20246.155.64.1 to 246.155.79.254246.155.79.2554,094
54246.155.80.0/20246.155.80.1 to 246.155.95.254246.155.95.2554,094
55246.155.96.0/20246.155.96.1 to 246.155.111.254246.155.111.2554,094
56246.155.112.0/20246.155.112.1 to 246.155.127.254246.155.127.2554,094
57246.155.128.0/20246.155.128.1 to 246.155.143.254246.155.143.2554,094
58246.155.144.0/20246.155.144.1 to 246.155.159.254246.155.159.2554,094
59246.155.160.0/20246.155.160.1 to 246.155.175.254246.155.175.2554,094
60246.155.176.0/20246.155.176.1 to 246.155.191.254246.155.191.2554,094
61246.155.192.0/20246.155.192.1 to 246.155.207.254246.155.207.2554,094
62246.155.208.0/20246.155.208.1 to 246.155.223.254246.155.223.2554,094
63246.155.224.0/20246.155.224.1 to 246.155.239.254246.155.239.2554,094
64246.155.240.0/20246.155.240.1 to 246.155.255.254246.155.255.2554,094
65246.156.0.0/20246.156.0.1 to 246.156.15.254246.156.15.2554,094
66246.156.16.0/20246.156.16.1 to 246.156.31.254246.156.31.2554,094
67246.156.32.0/20246.156.32.1 to 246.156.47.254246.156.47.2554,094
68246.156.48.0/20246.156.48.1 to 246.156.63.254246.156.63.2554,094
69246.156.64.0/20246.156.64.1 to 246.156.79.254246.156.79.2554,094
70246.156.80.0/20246.156.80.1 to 246.156.95.254246.156.95.2554,094
71246.156.96.0/20246.156.96.1 to 246.156.111.254246.156.111.2554,094
72246.156.112.0/20246.156.112.1 to 246.156.127.254246.156.127.2554,094
73246.156.128.0/20246.156.128.1 to 246.156.143.254246.156.143.2554,094
74246.156.144.0/20246.156.144.1 to 246.156.159.254246.156.159.2554,094
75246.156.160.0/20246.156.160.1 to 246.156.175.254246.156.175.2554,094
76246.156.176.0/20246.156.176.1 to 246.156.191.254246.156.191.2554,094
77246.156.192.0/20246.156.192.1 to 246.156.207.254246.156.207.2554,094
78246.156.208.0/20246.156.208.1 to 246.156.223.254246.156.223.2554,094
79246.156.224.0/20246.156.224.1 to 246.156.239.254246.156.239.2554,094
80246.156.240.0/20246.156.240.1 to 246.156.255.254246.156.255.2554,094
81246.157.0.0/20246.157.0.1 to 246.157.15.254246.157.15.2554,094
82246.157.16.0/20246.157.16.1 to 246.157.31.254246.157.31.2554,094
83246.157.32.0/20246.157.32.1 to 246.157.47.254246.157.47.2554,094
84246.157.48.0/20246.157.48.1 to 246.157.63.254246.157.63.2554,094
85246.157.64.0/20246.157.64.1 to 246.157.79.254246.157.79.2554,094
86246.157.80.0/20246.157.80.1 to 246.157.95.254246.157.95.2554,094
87246.157.96.0/20246.157.96.1 to 246.157.111.254246.157.111.2554,094
88246.157.112.0/20246.157.112.1 to 246.157.127.254246.157.127.2554,094
89246.157.128.0/20246.157.128.1 to 246.157.143.254246.157.143.2554,094
90246.157.144.0/20246.157.144.1 to 246.157.159.254246.157.159.2554,094
91246.157.160.0/20246.157.160.1 to 246.157.175.254246.157.175.2554,094
92246.157.176.0/20246.157.176.1 to 246.157.191.254246.157.191.2554,094
93246.157.192.0/20246.157.192.1 to 246.157.207.254246.157.207.2554,094
94246.157.208.0/20246.157.208.1 to 246.157.223.254246.157.223.2554,094
95246.157.224.0/20246.157.224.1 to 246.157.239.254246.157.239.2554,094
96246.157.240.0/20246.157.240.1 to 246.157.255.254246.157.255.2554,094
97246.158.0.0/20246.158.0.1 to 246.158.15.254246.158.15.2554,094
98246.158.16.0/20246.158.16.1 to 246.158.31.254246.158.31.2554,094
99246.158.32.0/20246.158.32.1 to 246.158.47.254246.158.47.2554,094
100246.158.48.0/20246.158.48.1 to 246.158.63.254246.158.63.2554,094
101246.158.64.0/20246.158.64.1 to 246.158.79.254246.158.79.2554,094
102246.158.80.0/20246.158.80.1 to 246.158.95.254246.158.95.2554,094
103246.158.96.0/20246.158.96.1 to 246.158.111.254246.158.111.2554,094
104246.158.112.0/20246.158.112.1 to 246.158.127.254246.158.127.2554,094
105246.158.128.0/20246.158.128.1 to 246.158.143.254246.158.143.2554,094
106246.158.144.0/20246.158.144.1 to 246.158.159.254246.158.159.2554,094
107246.158.160.0/20246.158.160.1 to 246.158.175.254246.158.175.2554,094
108246.158.176.0/20246.158.176.1 to 246.158.191.254246.158.191.2554,094
109246.158.192.0/20246.158.192.1 to 246.158.207.254246.158.207.2554,094
110246.158.208.0/20246.158.208.1 to 246.158.223.254246.158.223.2554,094
111246.158.224.0/20246.158.224.1 to 246.158.239.254246.158.239.2554,094
112246.158.240.0/20246.158.240.1 to 246.158.255.254246.158.255.2554,094
113246.159.0.0/20246.159.0.1 to 246.159.15.254246.159.15.2554,094
114246.159.16.0/20246.159.16.1 to 246.159.31.254246.159.31.2554,094
115246.159.32.0/20246.159.32.1 to 246.159.47.254246.159.47.2554,094
116246.159.48.0/20246.159.48.1 to 246.159.63.254246.159.63.2554,094
117246.159.64.0/20246.159.64.1 to 246.159.79.254246.159.79.2554,094
118246.159.80.0/20246.159.80.1 to 246.159.95.254246.159.95.2554,094
119246.159.96.0/20246.159.96.1 to 246.159.111.254246.159.111.2554,094
120246.159.112.0/20246.159.112.1 to 246.159.127.254246.159.127.2554,094
121246.159.128.0/20246.159.128.1 to 246.159.143.254246.159.143.2554,094
122246.159.144.0/20246.159.144.1 to 246.159.159.254246.159.159.2554,094
123246.159.160.0/20246.159.160.1 to 246.159.175.254246.159.175.2554,094
124246.159.176.0/20246.159.176.1 to 246.159.191.254246.159.191.2554,094
125246.159.192.0/20246.159.192.1 to 246.159.207.254246.159.207.2554,094
126246.159.208.0/20246.159.208.1 to 246.159.223.254246.159.223.2554,094
127246.159.224.0/20246.159.224.1 to 246.159.239.254246.159.239.2554,094
128246.159.240.0/20246.159.240.1 to 246.159.255.254246.159.255.2554,094

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.