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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.

Network174.3.32.0/19
Usable hosts8,190
Subnet mask255.255.224.0
Addresses8,192
Network address
174.3.32.0
Broadcast address
174.3.63.255
First usable
174.3.32.1
Last usable
174.3.63.254
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 AE032000 · Integer 2919440384 to 2919448575
Reverse DNS zones
32.3.174.in-addr.arpa
33.3.174.in-addr.arpa
34.3.174.in-addr.arpa
35.3.174.in-addr.arpa
36.3.174.in-addr.arpa
37.3.174.in-addr.arpa
38.3.174.in-addr.arpa
39.3.174.in-addr.arpa
40.3.174.in-addr.arpa
41.3.174.in-addr.arpa
42.3.174.in-addr.arpa
43.3.174.in-addr.arpa
44.3.174.in-addr.arpa
45.3.174.in-addr.arpa
46.3.174.in-addr.arpa
47.3.174.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
Address10101110.00000011.00100000.00000000174.3.32.0
Subnet mask11111111.11111111.11100000.00000000255.255.224.0
Network10101110.00000011.00100000.00000000174.3.32.0
Broadcast10101110.00000011.00111111.11111111174.3.63.255
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)

174.3.32.0/19 makes 128 subnets of /26.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1174.3.32.0/26174.3.32.1 to 174.3.32.62174.3.32.6362
2174.3.32.64/26174.3.32.65 to 174.3.32.126174.3.32.12762
3174.3.32.128/26174.3.32.129 to 174.3.32.190174.3.32.19162
4174.3.32.192/26174.3.32.193 to 174.3.32.254174.3.32.25562
5174.3.33.0/26174.3.33.1 to 174.3.33.62174.3.33.6362
6174.3.33.64/26174.3.33.65 to 174.3.33.126174.3.33.12762
7174.3.33.128/26174.3.33.129 to 174.3.33.190174.3.33.19162
8174.3.33.192/26174.3.33.193 to 174.3.33.254174.3.33.25562
9174.3.34.0/26174.3.34.1 to 174.3.34.62174.3.34.6362
10174.3.34.64/26174.3.34.65 to 174.3.34.126174.3.34.12762
11174.3.34.128/26174.3.34.129 to 174.3.34.190174.3.34.19162
12174.3.34.192/26174.3.34.193 to 174.3.34.254174.3.34.25562
13174.3.35.0/26174.3.35.1 to 174.3.35.62174.3.35.6362
14174.3.35.64/26174.3.35.65 to 174.3.35.126174.3.35.12762
15174.3.35.128/26174.3.35.129 to 174.3.35.190174.3.35.19162
16174.3.35.192/26174.3.35.193 to 174.3.35.254174.3.35.25562
17174.3.36.0/26174.3.36.1 to 174.3.36.62174.3.36.6362
18174.3.36.64/26174.3.36.65 to 174.3.36.126174.3.36.12762
19174.3.36.128/26174.3.36.129 to 174.3.36.190174.3.36.19162
20174.3.36.192/26174.3.36.193 to 174.3.36.254174.3.36.25562
21174.3.37.0/26174.3.37.1 to 174.3.37.62174.3.37.6362
22174.3.37.64/26174.3.37.65 to 174.3.37.126174.3.37.12762
23174.3.37.128/26174.3.37.129 to 174.3.37.190174.3.37.19162
24174.3.37.192/26174.3.37.193 to 174.3.37.254174.3.37.25562
25174.3.38.0/26174.3.38.1 to 174.3.38.62174.3.38.6362
26174.3.38.64/26174.3.38.65 to 174.3.38.126174.3.38.12762
27174.3.38.128/26174.3.38.129 to 174.3.38.190174.3.38.19162
28174.3.38.192/26174.3.38.193 to 174.3.38.254174.3.38.25562
29174.3.39.0/26174.3.39.1 to 174.3.39.62174.3.39.6362
30174.3.39.64/26174.3.39.65 to 174.3.39.126174.3.39.12762
31174.3.39.128/26174.3.39.129 to 174.3.39.190174.3.39.19162
32174.3.39.192/26174.3.39.193 to 174.3.39.254174.3.39.25562
33174.3.40.0/26174.3.40.1 to 174.3.40.62174.3.40.6362
34174.3.40.64/26174.3.40.65 to 174.3.40.126174.3.40.12762
35174.3.40.128/26174.3.40.129 to 174.3.40.190174.3.40.19162
36174.3.40.192/26174.3.40.193 to 174.3.40.254174.3.40.25562
37174.3.41.0/26174.3.41.1 to 174.3.41.62174.3.41.6362
38174.3.41.64/26174.3.41.65 to 174.3.41.126174.3.41.12762
39174.3.41.128/26174.3.41.129 to 174.3.41.190174.3.41.19162
40174.3.41.192/26174.3.41.193 to 174.3.41.254174.3.41.25562
41174.3.42.0/26174.3.42.1 to 174.3.42.62174.3.42.6362
42174.3.42.64/26174.3.42.65 to 174.3.42.126174.3.42.12762
43174.3.42.128/26174.3.42.129 to 174.3.42.190174.3.42.19162
44174.3.42.192/26174.3.42.193 to 174.3.42.254174.3.42.25562
45174.3.43.0/26174.3.43.1 to 174.3.43.62174.3.43.6362
46174.3.43.64/26174.3.43.65 to 174.3.43.126174.3.43.12762
47174.3.43.128/26174.3.43.129 to 174.3.43.190174.3.43.19162
48174.3.43.192/26174.3.43.193 to 174.3.43.254174.3.43.25562
49174.3.44.0/26174.3.44.1 to 174.3.44.62174.3.44.6362
50174.3.44.64/26174.3.44.65 to 174.3.44.126174.3.44.12762
51174.3.44.128/26174.3.44.129 to 174.3.44.190174.3.44.19162
52174.3.44.192/26174.3.44.193 to 174.3.44.254174.3.44.25562
53174.3.45.0/26174.3.45.1 to 174.3.45.62174.3.45.6362
54174.3.45.64/26174.3.45.65 to 174.3.45.126174.3.45.12762
55174.3.45.128/26174.3.45.129 to 174.3.45.190174.3.45.19162
56174.3.45.192/26174.3.45.193 to 174.3.45.254174.3.45.25562
57174.3.46.0/26174.3.46.1 to 174.3.46.62174.3.46.6362
58174.3.46.64/26174.3.46.65 to 174.3.46.126174.3.46.12762
59174.3.46.128/26174.3.46.129 to 174.3.46.190174.3.46.19162
60174.3.46.192/26174.3.46.193 to 174.3.46.254174.3.46.25562
61174.3.47.0/26174.3.47.1 to 174.3.47.62174.3.47.6362
62174.3.47.64/26174.3.47.65 to 174.3.47.126174.3.47.12762
63174.3.47.128/26174.3.47.129 to 174.3.47.190174.3.47.19162
64174.3.47.192/26174.3.47.193 to 174.3.47.254174.3.47.25562
65174.3.48.0/26174.3.48.1 to 174.3.48.62174.3.48.6362
66174.3.48.64/26174.3.48.65 to 174.3.48.126174.3.48.12762
67174.3.48.128/26174.3.48.129 to 174.3.48.190174.3.48.19162
68174.3.48.192/26174.3.48.193 to 174.3.48.254174.3.48.25562
69174.3.49.0/26174.3.49.1 to 174.3.49.62174.3.49.6362
70174.3.49.64/26174.3.49.65 to 174.3.49.126174.3.49.12762
71174.3.49.128/26174.3.49.129 to 174.3.49.190174.3.49.19162
72174.3.49.192/26174.3.49.193 to 174.3.49.254174.3.49.25562
73174.3.50.0/26174.3.50.1 to 174.3.50.62174.3.50.6362
74174.3.50.64/26174.3.50.65 to 174.3.50.126174.3.50.12762
75174.3.50.128/26174.3.50.129 to 174.3.50.190174.3.50.19162
76174.3.50.192/26174.3.50.193 to 174.3.50.254174.3.50.25562
77174.3.51.0/26174.3.51.1 to 174.3.51.62174.3.51.6362
78174.3.51.64/26174.3.51.65 to 174.3.51.126174.3.51.12762
79174.3.51.128/26174.3.51.129 to 174.3.51.190174.3.51.19162
80174.3.51.192/26174.3.51.193 to 174.3.51.254174.3.51.25562
81174.3.52.0/26174.3.52.1 to 174.3.52.62174.3.52.6362
82174.3.52.64/26174.3.52.65 to 174.3.52.126174.3.52.12762
83174.3.52.128/26174.3.52.129 to 174.3.52.190174.3.52.19162
84174.3.52.192/26174.3.52.193 to 174.3.52.254174.3.52.25562
85174.3.53.0/26174.3.53.1 to 174.3.53.62174.3.53.6362
86174.3.53.64/26174.3.53.65 to 174.3.53.126174.3.53.12762
87174.3.53.128/26174.3.53.129 to 174.3.53.190174.3.53.19162
88174.3.53.192/26174.3.53.193 to 174.3.53.254174.3.53.25562
89174.3.54.0/26174.3.54.1 to 174.3.54.62174.3.54.6362
90174.3.54.64/26174.3.54.65 to 174.3.54.126174.3.54.12762
91174.3.54.128/26174.3.54.129 to 174.3.54.190174.3.54.19162
92174.3.54.192/26174.3.54.193 to 174.3.54.254174.3.54.25562
93174.3.55.0/26174.3.55.1 to 174.3.55.62174.3.55.6362
94174.3.55.64/26174.3.55.65 to 174.3.55.126174.3.55.12762
95174.3.55.128/26174.3.55.129 to 174.3.55.190174.3.55.19162
96174.3.55.192/26174.3.55.193 to 174.3.55.254174.3.55.25562
97174.3.56.0/26174.3.56.1 to 174.3.56.62174.3.56.6362
98174.3.56.64/26174.3.56.65 to 174.3.56.126174.3.56.12762
99174.3.56.128/26174.3.56.129 to 174.3.56.190174.3.56.19162
100174.3.56.192/26174.3.56.193 to 174.3.56.254174.3.56.25562
101174.3.57.0/26174.3.57.1 to 174.3.57.62174.3.57.6362
102174.3.57.64/26174.3.57.65 to 174.3.57.126174.3.57.12762
103174.3.57.128/26174.3.57.129 to 174.3.57.190174.3.57.19162
104174.3.57.192/26174.3.57.193 to 174.3.57.254174.3.57.25562
105174.3.58.0/26174.3.58.1 to 174.3.58.62174.3.58.6362
106174.3.58.64/26174.3.58.65 to 174.3.58.126174.3.58.12762
107174.3.58.128/26174.3.58.129 to 174.3.58.190174.3.58.19162
108174.3.58.192/26174.3.58.193 to 174.3.58.254174.3.58.25562
109174.3.59.0/26174.3.59.1 to 174.3.59.62174.3.59.6362
110174.3.59.64/26174.3.59.65 to 174.3.59.126174.3.59.12762
111174.3.59.128/26174.3.59.129 to 174.3.59.190174.3.59.19162
112174.3.59.192/26174.3.59.193 to 174.3.59.254174.3.59.25562
113174.3.60.0/26174.3.60.1 to 174.3.60.62174.3.60.6362
114174.3.60.64/26174.3.60.65 to 174.3.60.126174.3.60.12762
115174.3.60.128/26174.3.60.129 to 174.3.60.190174.3.60.19162
116174.3.60.192/26174.3.60.193 to 174.3.60.254174.3.60.25562
117174.3.61.0/26174.3.61.1 to 174.3.61.62174.3.61.6362
118174.3.61.64/26174.3.61.65 to 174.3.61.126174.3.61.12762
119174.3.61.128/26174.3.61.129 to 174.3.61.190174.3.61.19162
120174.3.61.192/26174.3.61.193 to 174.3.61.254174.3.61.25562
121174.3.62.0/26174.3.62.1 to 174.3.62.62174.3.62.6362
122174.3.62.64/26174.3.62.65 to 174.3.62.126174.3.62.12762
123174.3.62.128/26174.3.62.129 to 174.3.62.190174.3.62.19162
124174.3.62.192/26174.3.62.193 to 174.3.62.254174.3.62.25562
125174.3.63.0/26174.3.63.1 to 174.3.63.62174.3.63.6362
126174.3.63.64/26174.3.63.65 to 174.3.63.126174.3.63.12762
127174.3.63.128/26174.3.63.129 to 174.3.63.190174.3.63.19162
128174.3.63.192/26174.3.63.193 to 174.3.63.254174.3.63.25562

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.