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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.

Network148.26.64.0/19
Usable hosts8,190
Subnet mask255.255.224.0
Addresses8,192
Network address
148.26.64.0
Broadcast address
148.26.95.255
First usable
148.26.64.1
Last usable
148.26.95.254
Usable hosts
8,190 (8,192 less the network and broadcast addresses)
Subnet mask
255.255.224.0
Wildcard mask
0.0.31.255 (Cisco ACLs, OSPF)
Prefix length
/19
Type
Public public
Old class
B (default /16)
As numbers
Hex 941A4000 · Integer 2484748288 to 2484756479
Reverse DNS zones
64.26.148.in-addr.arpa
65.26.148.in-addr.arpa
66.26.148.in-addr.arpa
67.26.148.in-addr.arpa
68.26.148.in-addr.arpa
69.26.148.in-addr.arpa
70.26.148.in-addr.arpa
71.26.148.in-addr.arpa
72.26.148.in-addr.arpa
73.26.148.in-addr.arpa
74.26.148.in-addr.arpa
75.26.148.in-addr.arpa
76.26.148.in-addr.arpa
77.26.148.in-addr.arpa
78.26.148.in-addr.arpa
79.26.148.in-addr.arpa
and 16 more
/19 is not on a 8-bit boundary, so it takes 32 /24 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address10010100.00011010.01000000.00000000148.26.64.0
Subnet mask11111111.11111111.11100000.00000000255.255.224.0
Network10010100.00011010.01000000.00000000148.26.64.0
Broadcast10010100.00011010.01011111.11111111148.26.95.255
Split into smaller subnets/26
/20 (2)/21 (4)/22 (8)/23 (16)/24 (32)/25 (64)/26 (128)/27 (256)/28 (512)/29 (1,024)/30 (2,048)/31 (4,096)

148.26.64.0/19 makes 128 subnets of /26.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1148.26.64.0/26148.26.64.1 to 148.26.64.62148.26.64.6362
2148.26.64.64/26148.26.64.65 to 148.26.64.126148.26.64.12762
3148.26.64.128/26148.26.64.129 to 148.26.64.190148.26.64.19162
4148.26.64.192/26148.26.64.193 to 148.26.64.254148.26.64.25562
5148.26.65.0/26148.26.65.1 to 148.26.65.62148.26.65.6362
6148.26.65.64/26148.26.65.65 to 148.26.65.126148.26.65.12762
7148.26.65.128/26148.26.65.129 to 148.26.65.190148.26.65.19162
8148.26.65.192/26148.26.65.193 to 148.26.65.254148.26.65.25562
9148.26.66.0/26148.26.66.1 to 148.26.66.62148.26.66.6362
10148.26.66.64/26148.26.66.65 to 148.26.66.126148.26.66.12762
11148.26.66.128/26148.26.66.129 to 148.26.66.190148.26.66.19162
12148.26.66.192/26148.26.66.193 to 148.26.66.254148.26.66.25562
13148.26.67.0/26148.26.67.1 to 148.26.67.62148.26.67.6362
14148.26.67.64/26148.26.67.65 to 148.26.67.126148.26.67.12762
15148.26.67.128/26148.26.67.129 to 148.26.67.190148.26.67.19162
16148.26.67.192/26148.26.67.193 to 148.26.67.254148.26.67.25562
17148.26.68.0/26148.26.68.1 to 148.26.68.62148.26.68.6362
18148.26.68.64/26148.26.68.65 to 148.26.68.126148.26.68.12762
19148.26.68.128/26148.26.68.129 to 148.26.68.190148.26.68.19162
20148.26.68.192/26148.26.68.193 to 148.26.68.254148.26.68.25562
21148.26.69.0/26148.26.69.1 to 148.26.69.62148.26.69.6362
22148.26.69.64/26148.26.69.65 to 148.26.69.126148.26.69.12762
23148.26.69.128/26148.26.69.129 to 148.26.69.190148.26.69.19162
24148.26.69.192/26148.26.69.193 to 148.26.69.254148.26.69.25562
25148.26.70.0/26148.26.70.1 to 148.26.70.62148.26.70.6362
26148.26.70.64/26148.26.70.65 to 148.26.70.126148.26.70.12762
27148.26.70.128/26148.26.70.129 to 148.26.70.190148.26.70.19162
28148.26.70.192/26148.26.70.193 to 148.26.70.254148.26.70.25562
29148.26.71.0/26148.26.71.1 to 148.26.71.62148.26.71.6362
30148.26.71.64/26148.26.71.65 to 148.26.71.126148.26.71.12762
31148.26.71.128/26148.26.71.129 to 148.26.71.190148.26.71.19162
32148.26.71.192/26148.26.71.193 to 148.26.71.254148.26.71.25562
33148.26.72.0/26148.26.72.1 to 148.26.72.62148.26.72.6362
34148.26.72.64/26148.26.72.65 to 148.26.72.126148.26.72.12762
35148.26.72.128/26148.26.72.129 to 148.26.72.190148.26.72.19162
36148.26.72.192/26148.26.72.193 to 148.26.72.254148.26.72.25562
37148.26.73.0/26148.26.73.1 to 148.26.73.62148.26.73.6362
38148.26.73.64/26148.26.73.65 to 148.26.73.126148.26.73.12762
39148.26.73.128/26148.26.73.129 to 148.26.73.190148.26.73.19162
40148.26.73.192/26148.26.73.193 to 148.26.73.254148.26.73.25562
41148.26.74.0/26148.26.74.1 to 148.26.74.62148.26.74.6362
42148.26.74.64/26148.26.74.65 to 148.26.74.126148.26.74.12762
43148.26.74.128/26148.26.74.129 to 148.26.74.190148.26.74.19162
44148.26.74.192/26148.26.74.193 to 148.26.74.254148.26.74.25562
45148.26.75.0/26148.26.75.1 to 148.26.75.62148.26.75.6362
46148.26.75.64/26148.26.75.65 to 148.26.75.126148.26.75.12762
47148.26.75.128/26148.26.75.129 to 148.26.75.190148.26.75.19162
48148.26.75.192/26148.26.75.193 to 148.26.75.254148.26.75.25562
49148.26.76.0/26148.26.76.1 to 148.26.76.62148.26.76.6362
50148.26.76.64/26148.26.76.65 to 148.26.76.126148.26.76.12762
51148.26.76.128/26148.26.76.129 to 148.26.76.190148.26.76.19162
52148.26.76.192/26148.26.76.193 to 148.26.76.254148.26.76.25562
53148.26.77.0/26148.26.77.1 to 148.26.77.62148.26.77.6362
54148.26.77.64/26148.26.77.65 to 148.26.77.126148.26.77.12762
55148.26.77.128/26148.26.77.129 to 148.26.77.190148.26.77.19162
56148.26.77.192/26148.26.77.193 to 148.26.77.254148.26.77.25562
57148.26.78.0/26148.26.78.1 to 148.26.78.62148.26.78.6362
58148.26.78.64/26148.26.78.65 to 148.26.78.126148.26.78.12762
59148.26.78.128/26148.26.78.129 to 148.26.78.190148.26.78.19162
60148.26.78.192/26148.26.78.193 to 148.26.78.254148.26.78.25562
61148.26.79.0/26148.26.79.1 to 148.26.79.62148.26.79.6362
62148.26.79.64/26148.26.79.65 to 148.26.79.126148.26.79.12762
63148.26.79.128/26148.26.79.129 to 148.26.79.190148.26.79.19162
64148.26.79.192/26148.26.79.193 to 148.26.79.254148.26.79.25562
65148.26.80.0/26148.26.80.1 to 148.26.80.62148.26.80.6362
66148.26.80.64/26148.26.80.65 to 148.26.80.126148.26.80.12762
67148.26.80.128/26148.26.80.129 to 148.26.80.190148.26.80.19162
68148.26.80.192/26148.26.80.193 to 148.26.80.254148.26.80.25562
69148.26.81.0/26148.26.81.1 to 148.26.81.62148.26.81.6362
70148.26.81.64/26148.26.81.65 to 148.26.81.126148.26.81.12762
71148.26.81.128/26148.26.81.129 to 148.26.81.190148.26.81.19162
72148.26.81.192/26148.26.81.193 to 148.26.81.254148.26.81.25562
73148.26.82.0/26148.26.82.1 to 148.26.82.62148.26.82.6362
74148.26.82.64/26148.26.82.65 to 148.26.82.126148.26.82.12762
75148.26.82.128/26148.26.82.129 to 148.26.82.190148.26.82.19162
76148.26.82.192/26148.26.82.193 to 148.26.82.254148.26.82.25562
77148.26.83.0/26148.26.83.1 to 148.26.83.62148.26.83.6362
78148.26.83.64/26148.26.83.65 to 148.26.83.126148.26.83.12762
79148.26.83.128/26148.26.83.129 to 148.26.83.190148.26.83.19162
80148.26.83.192/26148.26.83.193 to 148.26.83.254148.26.83.25562
81148.26.84.0/26148.26.84.1 to 148.26.84.62148.26.84.6362
82148.26.84.64/26148.26.84.65 to 148.26.84.126148.26.84.12762
83148.26.84.128/26148.26.84.129 to 148.26.84.190148.26.84.19162
84148.26.84.192/26148.26.84.193 to 148.26.84.254148.26.84.25562
85148.26.85.0/26148.26.85.1 to 148.26.85.62148.26.85.6362
86148.26.85.64/26148.26.85.65 to 148.26.85.126148.26.85.12762
87148.26.85.128/26148.26.85.129 to 148.26.85.190148.26.85.19162
88148.26.85.192/26148.26.85.193 to 148.26.85.254148.26.85.25562
89148.26.86.0/26148.26.86.1 to 148.26.86.62148.26.86.6362
90148.26.86.64/26148.26.86.65 to 148.26.86.126148.26.86.12762
91148.26.86.128/26148.26.86.129 to 148.26.86.190148.26.86.19162
92148.26.86.192/26148.26.86.193 to 148.26.86.254148.26.86.25562
93148.26.87.0/26148.26.87.1 to 148.26.87.62148.26.87.6362
94148.26.87.64/26148.26.87.65 to 148.26.87.126148.26.87.12762
95148.26.87.128/26148.26.87.129 to 148.26.87.190148.26.87.19162
96148.26.87.192/26148.26.87.193 to 148.26.87.254148.26.87.25562
97148.26.88.0/26148.26.88.1 to 148.26.88.62148.26.88.6362
98148.26.88.64/26148.26.88.65 to 148.26.88.126148.26.88.12762
99148.26.88.128/26148.26.88.129 to 148.26.88.190148.26.88.19162
100148.26.88.192/26148.26.88.193 to 148.26.88.254148.26.88.25562
101148.26.89.0/26148.26.89.1 to 148.26.89.62148.26.89.6362
102148.26.89.64/26148.26.89.65 to 148.26.89.126148.26.89.12762
103148.26.89.128/26148.26.89.129 to 148.26.89.190148.26.89.19162
104148.26.89.192/26148.26.89.193 to 148.26.89.254148.26.89.25562
105148.26.90.0/26148.26.90.1 to 148.26.90.62148.26.90.6362
106148.26.90.64/26148.26.90.65 to 148.26.90.126148.26.90.12762
107148.26.90.128/26148.26.90.129 to 148.26.90.190148.26.90.19162
108148.26.90.192/26148.26.90.193 to 148.26.90.254148.26.90.25562
109148.26.91.0/26148.26.91.1 to 148.26.91.62148.26.91.6362
110148.26.91.64/26148.26.91.65 to 148.26.91.126148.26.91.12762
111148.26.91.128/26148.26.91.129 to 148.26.91.190148.26.91.19162
112148.26.91.192/26148.26.91.193 to 148.26.91.254148.26.91.25562
113148.26.92.0/26148.26.92.1 to 148.26.92.62148.26.92.6362
114148.26.92.64/26148.26.92.65 to 148.26.92.126148.26.92.12762
115148.26.92.128/26148.26.92.129 to 148.26.92.190148.26.92.19162
116148.26.92.192/26148.26.92.193 to 148.26.92.254148.26.92.25562
117148.26.93.0/26148.26.93.1 to 148.26.93.62148.26.93.6362
118148.26.93.64/26148.26.93.65 to 148.26.93.126148.26.93.12762
119148.26.93.128/26148.26.93.129 to 148.26.93.190148.26.93.19162
120148.26.93.192/26148.26.93.193 to 148.26.93.254148.26.93.25562
121148.26.94.0/26148.26.94.1 to 148.26.94.62148.26.94.6362
122148.26.94.64/26148.26.94.65 to 148.26.94.126148.26.94.12762
123148.26.94.128/26148.26.94.129 to 148.26.94.190148.26.94.19162
124148.26.94.192/26148.26.94.193 to 148.26.94.254148.26.94.25562
125148.26.95.0/26148.26.95.1 to 148.26.95.62148.26.95.6362
126148.26.95.64/26148.26.95.65 to 148.26.95.126148.26.95.12762
127148.26.95.128/26148.26.95.129 to 148.26.95.190148.26.95.19162
128148.26.95.192/26148.26.95.193 to 148.26.95.254148.26.95.25562

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.