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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.

Network149.96.0.0/13
Usable hosts524,286
Subnet mask255.248.0.0
Addresses524,288
Network address
149.96.0.0
Broadcast address
149.103.255.255
First usable
149.96.0.1
Last usable
149.103.255.254
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
Public public
Old class
B (default /16)
As numbers
Hex 95600000 · Integer 2506096640 to 2506620927
Reverse DNS zones
96.149.in-addr.arpa
97.149.in-addr.arpa
98.149.in-addr.arpa
99.149.in-addr.arpa
100.149.in-addr.arpa
101.149.in-addr.arpa
102.149.in-addr.arpa
103.149.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
Address10010101.01100000.00000000.00000000149.96.0.0
Subnet mask11111111.11111000.00000000.00000000255.248.0.0
Network10010101.01100000.00000000.00000000149.96.0.0
Broadcast10010101.01100111.11111111.11111111149.103.255.255
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)

149.96.0.0/13 makes 128 subnets of /20.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1149.96.0.0/20149.96.0.1 to 149.96.15.254149.96.15.2554,094
2149.96.16.0/20149.96.16.1 to 149.96.31.254149.96.31.2554,094
3149.96.32.0/20149.96.32.1 to 149.96.47.254149.96.47.2554,094
4149.96.48.0/20149.96.48.1 to 149.96.63.254149.96.63.2554,094
5149.96.64.0/20149.96.64.1 to 149.96.79.254149.96.79.2554,094
6149.96.80.0/20149.96.80.1 to 149.96.95.254149.96.95.2554,094
7149.96.96.0/20149.96.96.1 to 149.96.111.254149.96.111.2554,094
8149.96.112.0/20149.96.112.1 to 149.96.127.254149.96.127.2554,094
9149.96.128.0/20149.96.128.1 to 149.96.143.254149.96.143.2554,094
10149.96.144.0/20149.96.144.1 to 149.96.159.254149.96.159.2554,094
11149.96.160.0/20149.96.160.1 to 149.96.175.254149.96.175.2554,094
12149.96.176.0/20149.96.176.1 to 149.96.191.254149.96.191.2554,094
13149.96.192.0/20149.96.192.1 to 149.96.207.254149.96.207.2554,094
14149.96.208.0/20149.96.208.1 to 149.96.223.254149.96.223.2554,094
15149.96.224.0/20149.96.224.1 to 149.96.239.254149.96.239.2554,094
16149.96.240.0/20149.96.240.1 to 149.96.255.254149.96.255.2554,094
17149.97.0.0/20149.97.0.1 to 149.97.15.254149.97.15.2554,094
18149.97.16.0/20149.97.16.1 to 149.97.31.254149.97.31.2554,094
19149.97.32.0/20149.97.32.1 to 149.97.47.254149.97.47.2554,094
20149.97.48.0/20149.97.48.1 to 149.97.63.254149.97.63.2554,094
21149.97.64.0/20149.97.64.1 to 149.97.79.254149.97.79.2554,094
22149.97.80.0/20149.97.80.1 to 149.97.95.254149.97.95.2554,094
23149.97.96.0/20149.97.96.1 to 149.97.111.254149.97.111.2554,094
24149.97.112.0/20149.97.112.1 to 149.97.127.254149.97.127.2554,094
25149.97.128.0/20149.97.128.1 to 149.97.143.254149.97.143.2554,094
26149.97.144.0/20149.97.144.1 to 149.97.159.254149.97.159.2554,094
27149.97.160.0/20149.97.160.1 to 149.97.175.254149.97.175.2554,094
28149.97.176.0/20149.97.176.1 to 149.97.191.254149.97.191.2554,094
29149.97.192.0/20149.97.192.1 to 149.97.207.254149.97.207.2554,094
30149.97.208.0/20149.97.208.1 to 149.97.223.254149.97.223.2554,094
31149.97.224.0/20149.97.224.1 to 149.97.239.254149.97.239.2554,094
32149.97.240.0/20149.97.240.1 to 149.97.255.254149.97.255.2554,094
33149.98.0.0/20149.98.0.1 to 149.98.15.254149.98.15.2554,094
34149.98.16.0/20149.98.16.1 to 149.98.31.254149.98.31.2554,094
35149.98.32.0/20149.98.32.1 to 149.98.47.254149.98.47.2554,094
36149.98.48.0/20149.98.48.1 to 149.98.63.254149.98.63.2554,094
37149.98.64.0/20149.98.64.1 to 149.98.79.254149.98.79.2554,094
38149.98.80.0/20149.98.80.1 to 149.98.95.254149.98.95.2554,094
39149.98.96.0/20149.98.96.1 to 149.98.111.254149.98.111.2554,094
40149.98.112.0/20149.98.112.1 to 149.98.127.254149.98.127.2554,094
41149.98.128.0/20149.98.128.1 to 149.98.143.254149.98.143.2554,094
42149.98.144.0/20149.98.144.1 to 149.98.159.254149.98.159.2554,094
43149.98.160.0/20149.98.160.1 to 149.98.175.254149.98.175.2554,094
44149.98.176.0/20149.98.176.1 to 149.98.191.254149.98.191.2554,094
45149.98.192.0/20149.98.192.1 to 149.98.207.254149.98.207.2554,094
46149.98.208.0/20149.98.208.1 to 149.98.223.254149.98.223.2554,094
47149.98.224.0/20149.98.224.1 to 149.98.239.254149.98.239.2554,094
48149.98.240.0/20149.98.240.1 to 149.98.255.254149.98.255.2554,094
49149.99.0.0/20149.99.0.1 to 149.99.15.254149.99.15.2554,094
50149.99.16.0/20149.99.16.1 to 149.99.31.254149.99.31.2554,094
51149.99.32.0/20149.99.32.1 to 149.99.47.254149.99.47.2554,094
52149.99.48.0/20149.99.48.1 to 149.99.63.254149.99.63.2554,094
53149.99.64.0/20149.99.64.1 to 149.99.79.254149.99.79.2554,094
54149.99.80.0/20149.99.80.1 to 149.99.95.254149.99.95.2554,094
55149.99.96.0/20149.99.96.1 to 149.99.111.254149.99.111.2554,094
56149.99.112.0/20149.99.112.1 to 149.99.127.254149.99.127.2554,094
57149.99.128.0/20149.99.128.1 to 149.99.143.254149.99.143.2554,094
58149.99.144.0/20149.99.144.1 to 149.99.159.254149.99.159.2554,094
59149.99.160.0/20149.99.160.1 to 149.99.175.254149.99.175.2554,094
60149.99.176.0/20149.99.176.1 to 149.99.191.254149.99.191.2554,094
61149.99.192.0/20149.99.192.1 to 149.99.207.254149.99.207.2554,094
62149.99.208.0/20149.99.208.1 to 149.99.223.254149.99.223.2554,094
63149.99.224.0/20149.99.224.1 to 149.99.239.254149.99.239.2554,094
64149.99.240.0/20149.99.240.1 to 149.99.255.254149.99.255.2554,094
65149.100.0.0/20149.100.0.1 to 149.100.15.254149.100.15.2554,094
66149.100.16.0/20149.100.16.1 to 149.100.31.254149.100.31.2554,094
67149.100.32.0/20149.100.32.1 to 149.100.47.254149.100.47.2554,094
68149.100.48.0/20149.100.48.1 to 149.100.63.254149.100.63.2554,094
69149.100.64.0/20149.100.64.1 to 149.100.79.254149.100.79.2554,094
70149.100.80.0/20149.100.80.1 to 149.100.95.254149.100.95.2554,094
71149.100.96.0/20149.100.96.1 to 149.100.111.254149.100.111.2554,094
72149.100.112.0/20149.100.112.1 to 149.100.127.254149.100.127.2554,094
73149.100.128.0/20149.100.128.1 to 149.100.143.254149.100.143.2554,094
74149.100.144.0/20149.100.144.1 to 149.100.159.254149.100.159.2554,094
75149.100.160.0/20149.100.160.1 to 149.100.175.254149.100.175.2554,094
76149.100.176.0/20149.100.176.1 to 149.100.191.254149.100.191.2554,094
77149.100.192.0/20149.100.192.1 to 149.100.207.254149.100.207.2554,094
78149.100.208.0/20149.100.208.1 to 149.100.223.254149.100.223.2554,094
79149.100.224.0/20149.100.224.1 to 149.100.239.254149.100.239.2554,094
80149.100.240.0/20149.100.240.1 to 149.100.255.254149.100.255.2554,094
81149.101.0.0/20149.101.0.1 to 149.101.15.254149.101.15.2554,094
82149.101.16.0/20149.101.16.1 to 149.101.31.254149.101.31.2554,094
83149.101.32.0/20149.101.32.1 to 149.101.47.254149.101.47.2554,094
84149.101.48.0/20149.101.48.1 to 149.101.63.254149.101.63.2554,094
85149.101.64.0/20149.101.64.1 to 149.101.79.254149.101.79.2554,094
86149.101.80.0/20149.101.80.1 to 149.101.95.254149.101.95.2554,094
87149.101.96.0/20149.101.96.1 to 149.101.111.254149.101.111.2554,094
88149.101.112.0/20149.101.112.1 to 149.101.127.254149.101.127.2554,094
89149.101.128.0/20149.101.128.1 to 149.101.143.254149.101.143.2554,094
90149.101.144.0/20149.101.144.1 to 149.101.159.254149.101.159.2554,094
91149.101.160.0/20149.101.160.1 to 149.101.175.254149.101.175.2554,094
92149.101.176.0/20149.101.176.1 to 149.101.191.254149.101.191.2554,094
93149.101.192.0/20149.101.192.1 to 149.101.207.254149.101.207.2554,094
94149.101.208.0/20149.101.208.1 to 149.101.223.254149.101.223.2554,094
95149.101.224.0/20149.101.224.1 to 149.101.239.254149.101.239.2554,094
96149.101.240.0/20149.101.240.1 to 149.101.255.254149.101.255.2554,094
97149.102.0.0/20149.102.0.1 to 149.102.15.254149.102.15.2554,094
98149.102.16.0/20149.102.16.1 to 149.102.31.254149.102.31.2554,094
99149.102.32.0/20149.102.32.1 to 149.102.47.254149.102.47.2554,094
100149.102.48.0/20149.102.48.1 to 149.102.63.254149.102.63.2554,094
101149.102.64.0/20149.102.64.1 to 149.102.79.254149.102.79.2554,094
102149.102.80.0/20149.102.80.1 to 149.102.95.254149.102.95.2554,094
103149.102.96.0/20149.102.96.1 to 149.102.111.254149.102.111.2554,094
104149.102.112.0/20149.102.112.1 to 149.102.127.254149.102.127.2554,094
105149.102.128.0/20149.102.128.1 to 149.102.143.254149.102.143.2554,094
106149.102.144.0/20149.102.144.1 to 149.102.159.254149.102.159.2554,094
107149.102.160.0/20149.102.160.1 to 149.102.175.254149.102.175.2554,094
108149.102.176.0/20149.102.176.1 to 149.102.191.254149.102.191.2554,094
109149.102.192.0/20149.102.192.1 to 149.102.207.254149.102.207.2554,094
110149.102.208.0/20149.102.208.1 to 149.102.223.254149.102.223.2554,094
111149.102.224.0/20149.102.224.1 to 149.102.239.254149.102.239.2554,094
112149.102.240.0/20149.102.240.1 to 149.102.255.254149.102.255.2554,094
113149.103.0.0/20149.103.0.1 to 149.103.15.254149.103.15.2554,094
114149.103.16.0/20149.103.16.1 to 149.103.31.254149.103.31.2554,094
115149.103.32.0/20149.103.32.1 to 149.103.47.254149.103.47.2554,094
116149.103.48.0/20149.103.48.1 to 149.103.63.254149.103.63.2554,094
117149.103.64.0/20149.103.64.1 to 149.103.79.254149.103.79.2554,094
118149.103.80.0/20149.103.80.1 to 149.103.95.254149.103.95.2554,094
119149.103.96.0/20149.103.96.1 to 149.103.111.254149.103.111.2554,094
120149.103.112.0/20149.103.112.1 to 149.103.127.254149.103.127.2554,094
121149.103.128.0/20149.103.128.1 to 149.103.143.254149.103.143.2554,094
122149.103.144.0/20149.103.144.1 to 149.103.159.254149.103.159.2554,094
123149.103.160.0/20149.103.160.1 to 149.103.175.254149.103.175.2554,094
124149.103.176.0/20149.103.176.1 to 149.103.191.254149.103.191.2554,094
125149.103.192.0/20149.103.192.1 to 149.103.207.254149.103.207.2554,094
126149.103.208.0/20149.103.208.1 to 149.103.223.254149.103.223.2554,094
127149.103.224.0/20149.103.224.1 to 149.103.239.254149.103.239.2554,094
128149.103.240.0/20149.103.240.1 to 149.103.255.254149.103.255.2554,094

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.