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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.

Network110.0.64.0/19
Usable hosts8,190
Subnet mask255.255.224.0
Addresses8,192
Network address
110.0.64.0
Broadcast address
110.0.95.255
First usable
110.0.64.1
Last usable
110.0.95.254
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
A (default /8)
As numbers
Hex 6E004000 · Integer 1845510144 to 1845518335
Reverse DNS zones
64.0.110.in-addr.arpa
65.0.110.in-addr.arpa
66.0.110.in-addr.arpa
67.0.110.in-addr.arpa
68.0.110.in-addr.arpa
69.0.110.in-addr.arpa
70.0.110.in-addr.arpa
71.0.110.in-addr.arpa
72.0.110.in-addr.arpa
73.0.110.in-addr.arpa
74.0.110.in-addr.arpa
75.0.110.in-addr.arpa
76.0.110.in-addr.arpa
77.0.110.in-addr.arpa
78.0.110.in-addr.arpa
79.0.110.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
Address01101110.00000000.01000000.00000000110.0.64.0
Subnet mask11111111.11111111.11100000.00000000255.255.224.0
Network01101110.00000000.01000000.00000000110.0.64.0
Broadcast01101110.00000000.01011111.11111111110.0.95.255
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)

110.0.64.0/19 makes 128 subnets of /26.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1110.0.64.0/26110.0.64.1 to 110.0.64.62110.0.64.6362
2110.0.64.64/26110.0.64.65 to 110.0.64.126110.0.64.12762
3110.0.64.128/26110.0.64.129 to 110.0.64.190110.0.64.19162
4110.0.64.192/26110.0.64.193 to 110.0.64.254110.0.64.25562
5110.0.65.0/26110.0.65.1 to 110.0.65.62110.0.65.6362
6110.0.65.64/26110.0.65.65 to 110.0.65.126110.0.65.12762
7110.0.65.128/26110.0.65.129 to 110.0.65.190110.0.65.19162
8110.0.65.192/26110.0.65.193 to 110.0.65.254110.0.65.25562
9110.0.66.0/26110.0.66.1 to 110.0.66.62110.0.66.6362
10110.0.66.64/26110.0.66.65 to 110.0.66.126110.0.66.12762
11110.0.66.128/26110.0.66.129 to 110.0.66.190110.0.66.19162
12110.0.66.192/26110.0.66.193 to 110.0.66.254110.0.66.25562
13110.0.67.0/26110.0.67.1 to 110.0.67.62110.0.67.6362
14110.0.67.64/26110.0.67.65 to 110.0.67.126110.0.67.12762
15110.0.67.128/26110.0.67.129 to 110.0.67.190110.0.67.19162
16110.0.67.192/26110.0.67.193 to 110.0.67.254110.0.67.25562
17110.0.68.0/26110.0.68.1 to 110.0.68.62110.0.68.6362
18110.0.68.64/26110.0.68.65 to 110.0.68.126110.0.68.12762
19110.0.68.128/26110.0.68.129 to 110.0.68.190110.0.68.19162
20110.0.68.192/26110.0.68.193 to 110.0.68.254110.0.68.25562
21110.0.69.0/26110.0.69.1 to 110.0.69.62110.0.69.6362
22110.0.69.64/26110.0.69.65 to 110.0.69.126110.0.69.12762
23110.0.69.128/26110.0.69.129 to 110.0.69.190110.0.69.19162
24110.0.69.192/26110.0.69.193 to 110.0.69.254110.0.69.25562
25110.0.70.0/26110.0.70.1 to 110.0.70.62110.0.70.6362
26110.0.70.64/26110.0.70.65 to 110.0.70.126110.0.70.12762
27110.0.70.128/26110.0.70.129 to 110.0.70.190110.0.70.19162
28110.0.70.192/26110.0.70.193 to 110.0.70.254110.0.70.25562
29110.0.71.0/26110.0.71.1 to 110.0.71.62110.0.71.6362
30110.0.71.64/26110.0.71.65 to 110.0.71.126110.0.71.12762
31110.0.71.128/26110.0.71.129 to 110.0.71.190110.0.71.19162
32110.0.71.192/26110.0.71.193 to 110.0.71.254110.0.71.25562
33110.0.72.0/26110.0.72.1 to 110.0.72.62110.0.72.6362
34110.0.72.64/26110.0.72.65 to 110.0.72.126110.0.72.12762
35110.0.72.128/26110.0.72.129 to 110.0.72.190110.0.72.19162
36110.0.72.192/26110.0.72.193 to 110.0.72.254110.0.72.25562
37110.0.73.0/26110.0.73.1 to 110.0.73.62110.0.73.6362
38110.0.73.64/26110.0.73.65 to 110.0.73.126110.0.73.12762
39110.0.73.128/26110.0.73.129 to 110.0.73.190110.0.73.19162
40110.0.73.192/26110.0.73.193 to 110.0.73.254110.0.73.25562
41110.0.74.0/26110.0.74.1 to 110.0.74.62110.0.74.6362
42110.0.74.64/26110.0.74.65 to 110.0.74.126110.0.74.12762
43110.0.74.128/26110.0.74.129 to 110.0.74.190110.0.74.19162
44110.0.74.192/26110.0.74.193 to 110.0.74.254110.0.74.25562
45110.0.75.0/26110.0.75.1 to 110.0.75.62110.0.75.6362
46110.0.75.64/26110.0.75.65 to 110.0.75.126110.0.75.12762
47110.0.75.128/26110.0.75.129 to 110.0.75.190110.0.75.19162
48110.0.75.192/26110.0.75.193 to 110.0.75.254110.0.75.25562
49110.0.76.0/26110.0.76.1 to 110.0.76.62110.0.76.6362
50110.0.76.64/26110.0.76.65 to 110.0.76.126110.0.76.12762
51110.0.76.128/26110.0.76.129 to 110.0.76.190110.0.76.19162
52110.0.76.192/26110.0.76.193 to 110.0.76.254110.0.76.25562
53110.0.77.0/26110.0.77.1 to 110.0.77.62110.0.77.6362
54110.0.77.64/26110.0.77.65 to 110.0.77.126110.0.77.12762
55110.0.77.128/26110.0.77.129 to 110.0.77.190110.0.77.19162
56110.0.77.192/26110.0.77.193 to 110.0.77.254110.0.77.25562
57110.0.78.0/26110.0.78.1 to 110.0.78.62110.0.78.6362
58110.0.78.64/26110.0.78.65 to 110.0.78.126110.0.78.12762
59110.0.78.128/26110.0.78.129 to 110.0.78.190110.0.78.19162
60110.0.78.192/26110.0.78.193 to 110.0.78.254110.0.78.25562
61110.0.79.0/26110.0.79.1 to 110.0.79.62110.0.79.6362
62110.0.79.64/26110.0.79.65 to 110.0.79.126110.0.79.12762
63110.0.79.128/26110.0.79.129 to 110.0.79.190110.0.79.19162
64110.0.79.192/26110.0.79.193 to 110.0.79.254110.0.79.25562
65110.0.80.0/26110.0.80.1 to 110.0.80.62110.0.80.6362
66110.0.80.64/26110.0.80.65 to 110.0.80.126110.0.80.12762
67110.0.80.128/26110.0.80.129 to 110.0.80.190110.0.80.19162
68110.0.80.192/26110.0.80.193 to 110.0.80.254110.0.80.25562
69110.0.81.0/26110.0.81.1 to 110.0.81.62110.0.81.6362
70110.0.81.64/26110.0.81.65 to 110.0.81.126110.0.81.12762
71110.0.81.128/26110.0.81.129 to 110.0.81.190110.0.81.19162
72110.0.81.192/26110.0.81.193 to 110.0.81.254110.0.81.25562
73110.0.82.0/26110.0.82.1 to 110.0.82.62110.0.82.6362
74110.0.82.64/26110.0.82.65 to 110.0.82.126110.0.82.12762
75110.0.82.128/26110.0.82.129 to 110.0.82.190110.0.82.19162
76110.0.82.192/26110.0.82.193 to 110.0.82.254110.0.82.25562
77110.0.83.0/26110.0.83.1 to 110.0.83.62110.0.83.6362
78110.0.83.64/26110.0.83.65 to 110.0.83.126110.0.83.12762
79110.0.83.128/26110.0.83.129 to 110.0.83.190110.0.83.19162
80110.0.83.192/26110.0.83.193 to 110.0.83.254110.0.83.25562
81110.0.84.0/26110.0.84.1 to 110.0.84.62110.0.84.6362
82110.0.84.64/26110.0.84.65 to 110.0.84.126110.0.84.12762
83110.0.84.128/26110.0.84.129 to 110.0.84.190110.0.84.19162
84110.0.84.192/26110.0.84.193 to 110.0.84.254110.0.84.25562
85110.0.85.0/26110.0.85.1 to 110.0.85.62110.0.85.6362
86110.0.85.64/26110.0.85.65 to 110.0.85.126110.0.85.12762
87110.0.85.128/26110.0.85.129 to 110.0.85.190110.0.85.19162
88110.0.85.192/26110.0.85.193 to 110.0.85.254110.0.85.25562
89110.0.86.0/26110.0.86.1 to 110.0.86.62110.0.86.6362
90110.0.86.64/26110.0.86.65 to 110.0.86.126110.0.86.12762
91110.0.86.128/26110.0.86.129 to 110.0.86.190110.0.86.19162
92110.0.86.192/26110.0.86.193 to 110.0.86.254110.0.86.25562
93110.0.87.0/26110.0.87.1 to 110.0.87.62110.0.87.6362
94110.0.87.64/26110.0.87.65 to 110.0.87.126110.0.87.12762
95110.0.87.128/26110.0.87.129 to 110.0.87.190110.0.87.19162
96110.0.87.192/26110.0.87.193 to 110.0.87.254110.0.87.25562
97110.0.88.0/26110.0.88.1 to 110.0.88.62110.0.88.6362
98110.0.88.64/26110.0.88.65 to 110.0.88.126110.0.88.12762
99110.0.88.128/26110.0.88.129 to 110.0.88.190110.0.88.19162
100110.0.88.192/26110.0.88.193 to 110.0.88.254110.0.88.25562
101110.0.89.0/26110.0.89.1 to 110.0.89.62110.0.89.6362
102110.0.89.64/26110.0.89.65 to 110.0.89.126110.0.89.12762
103110.0.89.128/26110.0.89.129 to 110.0.89.190110.0.89.19162
104110.0.89.192/26110.0.89.193 to 110.0.89.254110.0.89.25562
105110.0.90.0/26110.0.90.1 to 110.0.90.62110.0.90.6362
106110.0.90.64/26110.0.90.65 to 110.0.90.126110.0.90.12762
107110.0.90.128/26110.0.90.129 to 110.0.90.190110.0.90.19162
108110.0.90.192/26110.0.90.193 to 110.0.90.254110.0.90.25562
109110.0.91.0/26110.0.91.1 to 110.0.91.62110.0.91.6362
110110.0.91.64/26110.0.91.65 to 110.0.91.126110.0.91.12762
111110.0.91.128/26110.0.91.129 to 110.0.91.190110.0.91.19162
112110.0.91.192/26110.0.91.193 to 110.0.91.254110.0.91.25562
113110.0.92.0/26110.0.92.1 to 110.0.92.62110.0.92.6362
114110.0.92.64/26110.0.92.65 to 110.0.92.126110.0.92.12762
115110.0.92.128/26110.0.92.129 to 110.0.92.190110.0.92.19162
116110.0.92.192/26110.0.92.193 to 110.0.92.254110.0.92.25562
117110.0.93.0/26110.0.93.1 to 110.0.93.62110.0.93.6362
118110.0.93.64/26110.0.93.65 to 110.0.93.126110.0.93.12762
119110.0.93.128/26110.0.93.129 to 110.0.93.190110.0.93.19162
120110.0.93.192/26110.0.93.193 to 110.0.93.254110.0.93.25562
121110.0.94.0/26110.0.94.1 to 110.0.94.62110.0.94.6362
122110.0.94.64/26110.0.94.65 to 110.0.94.126110.0.94.12762
123110.0.94.128/26110.0.94.129 to 110.0.94.190110.0.94.19162
124110.0.94.192/26110.0.94.193 to 110.0.94.254110.0.94.25562
125110.0.95.0/26110.0.95.1 to 110.0.95.62110.0.95.6362
126110.0.95.64/26110.0.95.65 to 110.0.95.126110.0.95.12762
127110.0.95.128/26110.0.95.129 to 110.0.95.190110.0.95.19162
128110.0.95.192/26110.0.95.193 to 110.0.95.254110.0.95.25562

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.