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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.

Network46.0.0.0/10
Usable hosts4,194,302
Subnet mask255.192.0.0
Addresses4,194,304
Network address
46.0.0.0
Broadcast address
46.63.255.255
First usable
46.0.0.1
Last usable
46.63.255.254
Usable hosts
4,194,302 (4,194,304 less the network and broadcast addresses)
Subnet mask
255.192.0.0
Wildcard mask
0.63.255.255 (Cisco ACLs, OSPF)
Prefix length
/10
Type
Public public
Old class
A (default /8)
As numbers
Hex 2E000000 · Integer 771751936 to 775946239
Reverse DNS zones
0.46.in-addr.arpa
1.46.in-addr.arpa
2.46.in-addr.arpa
3.46.in-addr.arpa
4.46.in-addr.arpa
5.46.in-addr.arpa
6.46.in-addr.arpa
7.46.in-addr.arpa
8.46.in-addr.arpa
9.46.in-addr.arpa
10.46.in-addr.arpa
11.46.in-addr.arpa
12.46.in-addr.arpa
13.46.in-addr.arpa
14.46.in-addr.arpa
15.46.in-addr.arpa
and 48 more
/10 is not on a 8-bit boundary, so it takes 64 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address00101110.00000000.00000000.0000000046.0.0.0
Subnet mask11111111.11000000.00000000.00000000255.192.0.0
Network00101110.00000000.00000000.0000000046.0.0.0
Broadcast00101110.00111111.11111111.1111111146.63.255.255
Split into smaller subnets/17
/11 (2)/12 (4)/13 (8)/14 (16)/15 (32)/16 (64)/17 (128)/18 (256)/19 (512)/20 (1,024)/21 (2,048)/22 (4,096)

46.0.0.0/10 makes 128 subnets of /17.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
146.0.0.0/1746.0.0.1 to 46.0.127.25446.0.127.25532,766
246.0.128.0/1746.0.128.1 to 46.0.255.25446.0.255.25532,766
346.1.0.0/1746.1.0.1 to 46.1.127.25446.1.127.25532,766
446.1.128.0/1746.1.128.1 to 46.1.255.25446.1.255.25532,766
546.2.0.0/1746.2.0.1 to 46.2.127.25446.2.127.25532,766
646.2.128.0/1746.2.128.1 to 46.2.255.25446.2.255.25532,766
746.3.0.0/1746.3.0.1 to 46.3.127.25446.3.127.25532,766
846.3.128.0/1746.3.128.1 to 46.3.255.25446.3.255.25532,766
946.4.0.0/1746.4.0.1 to 46.4.127.25446.4.127.25532,766
1046.4.128.0/1746.4.128.1 to 46.4.255.25446.4.255.25532,766
1146.5.0.0/1746.5.0.1 to 46.5.127.25446.5.127.25532,766
1246.5.128.0/1746.5.128.1 to 46.5.255.25446.5.255.25532,766
1346.6.0.0/1746.6.0.1 to 46.6.127.25446.6.127.25532,766
1446.6.128.0/1746.6.128.1 to 46.6.255.25446.6.255.25532,766
1546.7.0.0/1746.7.0.1 to 46.7.127.25446.7.127.25532,766
1646.7.128.0/1746.7.128.1 to 46.7.255.25446.7.255.25532,766
1746.8.0.0/1746.8.0.1 to 46.8.127.25446.8.127.25532,766
1846.8.128.0/1746.8.128.1 to 46.8.255.25446.8.255.25532,766
1946.9.0.0/1746.9.0.1 to 46.9.127.25446.9.127.25532,766
2046.9.128.0/1746.9.128.1 to 46.9.255.25446.9.255.25532,766
2146.10.0.0/1746.10.0.1 to 46.10.127.25446.10.127.25532,766
2246.10.128.0/1746.10.128.1 to 46.10.255.25446.10.255.25532,766
2346.11.0.0/1746.11.0.1 to 46.11.127.25446.11.127.25532,766
2446.11.128.0/1746.11.128.1 to 46.11.255.25446.11.255.25532,766
2546.12.0.0/1746.12.0.1 to 46.12.127.25446.12.127.25532,766
2646.12.128.0/1746.12.128.1 to 46.12.255.25446.12.255.25532,766
2746.13.0.0/1746.13.0.1 to 46.13.127.25446.13.127.25532,766
2846.13.128.0/1746.13.128.1 to 46.13.255.25446.13.255.25532,766
2946.14.0.0/1746.14.0.1 to 46.14.127.25446.14.127.25532,766
3046.14.128.0/1746.14.128.1 to 46.14.255.25446.14.255.25532,766
3146.15.0.0/1746.15.0.1 to 46.15.127.25446.15.127.25532,766
3246.15.128.0/1746.15.128.1 to 46.15.255.25446.15.255.25532,766
3346.16.0.0/1746.16.0.1 to 46.16.127.25446.16.127.25532,766
3446.16.128.0/1746.16.128.1 to 46.16.255.25446.16.255.25532,766
3546.17.0.0/1746.17.0.1 to 46.17.127.25446.17.127.25532,766
3646.17.128.0/1746.17.128.1 to 46.17.255.25446.17.255.25532,766
3746.18.0.0/1746.18.0.1 to 46.18.127.25446.18.127.25532,766
3846.18.128.0/1746.18.128.1 to 46.18.255.25446.18.255.25532,766
3946.19.0.0/1746.19.0.1 to 46.19.127.25446.19.127.25532,766
4046.19.128.0/1746.19.128.1 to 46.19.255.25446.19.255.25532,766
4146.20.0.0/1746.20.0.1 to 46.20.127.25446.20.127.25532,766
4246.20.128.0/1746.20.128.1 to 46.20.255.25446.20.255.25532,766
4346.21.0.0/1746.21.0.1 to 46.21.127.25446.21.127.25532,766
4446.21.128.0/1746.21.128.1 to 46.21.255.25446.21.255.25532,766
4546.22.0.0/1746.22.0.1 to 46.22.127.25446.22.127.25532,766
4646.22.128.0/1746.22.128.1 to 46.22.255.25446.22.255.25532,766
4746.23.0.0/1746.23.0.1 to 46.23.127.25446.23.127.25532,766
4846.23.128.0/1746.23.128.1 to 46.23.255.25446.23.255.25532,766
4946.24.0.0/1746.24.0.1 to 46.24.127.25446.24.127.25532,766
5046.24.128.0/1746.24.128.1 to 46.24.255.25446.24.255.25532,766
5146.25.0.0/1746.25.0.1 to 46.25.127.25446.25.127.25532,766
5246.25.128.0/1746.25.128.1 to 46.25.255.25446.25.255.25532,766
5346.26.0.0/1746.26.0.1 to 46.26.127.25446.26.127.25532,766
5446.26.128.0/1746.26.128.1 to 46.26.255.25446.26.255.25532,766
5546.27.0.0/1746.27.0.1 to 46.27.127.25446.27.127.25532,766
5646.27.128.0/1746.27.128.1 to 46.27.255.25446.27.255.25532,766
5746.28.0.0/1746.28.0.1 to 46.28.127.25446.28.127.25532,766
5846.28.128.0/1746.28.128.1 to 46.28.255.25446.28.255.25532,766
5946.29.0.0/1746.29.0.1 to 46.29.127.25446.29.127.25532,766
6046.29.128.0/1746.29.128.1 to 46.29.255.25446.29.255.25532,766
6146.30.0.0/1746.30.0.1 to 46.30.127.25446.30.127.25532,766
6246.30.128.0/1746.30.128.1 to 46.30.255.25446.30.255.25532,766
6346.31.0.0/1746.31.0.1 to 46.31.127.25446.31.127.25532,766
6446.31.128.0/1746.31.128.1 to 46.31.255.25446.31.255.25532,766
6546.32.0.0/1746.32.0.1 to 46.32.127.25446.32.127.25532,766
6646.32.128.0/1746.32.128.1 to 46.32.255.25446.32.255.25532,766
6746.33.0.0/1746.33.0.1 to 46.33.127.25446.33.127.25532,766
6846.33.128.0/1746.33.128.1 to 46.33.255.25446.33.255.25532,766
6946.34.0.0/1746.34.0.1 to 46.34.127.25446.34.127.25532,766
7046.34.128.0/1746.34.128.1 to 46.34.255.25446.34.255.25532,766
7146.35.0.0/1746.35.0.1 to 46.35.127.25446.35.127.25532,766
7246.35.128.0/1746.35.128.1 to 46.35.255.25446.35.255.25532,766
7346.36.0.0/1746.36.0.1 to 46.36.127.25446.36.127.25532,766
7446.36.128.0/1746.36.128.1 to 46.36.255.25446.36.255.25532,766
7546.37.0.0/1746.37.0.1 to 46.37.127.25446.37.127.25532,766
7646.37.128.0/1746.37.128.1 to 46.37.255.25446.37.255.25532,766
7746.38.0.0/1746.38.0.1 to 46.38.127.25446.38.127.25532,766
7846.38.128.0/1746.38.128.1 to 46.38.255.25446.38.255.25532,766
7946.39.0.0/1746.39.0.1 to 46.39.127.25446.39.127.25532,766
8046.39.128.0/1746.39.128.1 to 46.39.255.25446.39.255.25532,766
8146.40.0.0/1746.40.0.1 to 46.40.127.25446.40.127.25532,766
8246.40.128.0/1746.40.128.1 to 46.40.255.25446.40.255.25532,766
8346.41.0.0/1746.41.0.1 to 46.41.127.25446.41.127.25532,766
8446.41.128.0/1746.41.128.1 to 46.41.255.25446.41.255.25532,766
8546.42.0.0/1746.42.0.1 to 46.42.127.25446.42.127.25532,766
8646.42.128.0/1746.42.128.1 to 46.42.255.25446.42.255.25532,766
8746.43.0.0/1746.43.0.1 to 46.43.127.25446.43.127.25532,766
8846.43.128.0/1746.43.128.1 to 46.43.255.25446.43.255.25532,766
8946.44.0.0/1746.44.0.1 to 46.44.127.25446.44.127.25532,766
9046.44.128.0/1746.44.128.1 to 46.44.255.25446.44.255.25532,766
9146.45.0.0/1746.45.0.1 to 46.45.127.25446.45.127.25532,766
9246.45.128.0/1746.45.128.1 to 46.45.255.25446.45.255.25532,766
9346.46.0.0/1746.46.0.1 to 46.46.127.25446.46.127.25532,766
9446.46.128.0/1746.46.128.1 to 46.46.255.25446.46.255.25532,766
9546.47.0.0/1746.47.0.1 to 46.47.127.25446.47.127.25532,766
9646.47.128.0/1746.47.128.1 to 46.47.255.25446.47.255.25532,766
9746.48.0.0/1746.48.0.1 to 46.48.127.25446.48.127.25532,766
9846.48.128.0/1746.48.128.1 to 46.48.255.25446.48.255.25532,766
9946.49.0.0/1746.49.0.1 to 46.49.127.25446.49.127.25532,766
10046.49.128.0/1746.49.128.1 to 46.49.255.25446.49.255.25532,766
10146.50.0.0/1746.50.0.1 to 46.50.127.25446.50.127.25532,766
10246.50.128.0/1746.50.128.1 to 46.50.255.25446.50.255.25532,766
10346.51.0.0/1746.51.0.1 to 46.51.127.25446.51.127.25532,766
10446.51.128.0/1746.51.128.1 to 46.51.255.25446.51.255.25532,766
10546.52.0.0/1746.52.0.1 to 46.52.127.25446.52.127.25532,766
10646.52.128.0/1746.52.128.1 to 46.52.255.25446.52.255.25532,766
10746.53.0.0/1746.53.0.1 to 46.53.127.25446.53.127.25532,766
10846.53.128.0/1746.53.128.1 to 46.53.255.25446.53.255.25532,766
10946.54.0.0/1746.54.0.1 to 46.54.127.25446.54.127.25532,766
11046.54.128.0/1746.54.128.1 to 46.54.255.25446.54.255.25532,766
11146.55.0.0/1746.55.0.1 to 46.55.127.25446.55.127.25532,766
11246.55.128.0/1746.55.128.1 to 46.55.255.25446.55.255.25532,766
11346.56.0.0/1746.56.0.1 to 46.56.127.25446.56.127.25532,766
11446.56.128.0/1746.56.128.1 to 46.56.255.25446.56.255.25532,766
11546.57.0.0/1746.57.0.1 to 46.57.127.25446.57.127.25532,766
11646.57.128.0/1746.57.128.1 to 46.57.255.25446.57.255.25532,766
11746.58.0.0/1746.58.0.1 to 46.58.127.25446.58.127.25532,766
11846.58.128.0/1746.58.128.1 to 46.58.255.25446.58.255.25532,766
11946.59.0.0/1746.59.0.1 to 46.59.127.25446.59.127.25532,766
12046.59.128.0/1746.59.128.1 to 46.59.255.25446.59.255.25532,766
12146.60.0.0/1746.60.0.1 to 46.60.127.25446.60.127.25532,766
12246.60.128.0/1746.60.128.1 to 46.60.255.25446.60.255.25532,766
12346.61.0.0/1746.61.0.1 to 46.61.127.25446.61.127.25532,766
12446.61.128.0/1746.61.128.1 to 46.61.255.25446.61.255.25532,766
12546.62.0.0/1746.62.0.1 to 46.62.127.25446.62.127.25532,766
12646.62.128.0/1746.62.128.1 to 46.62.255.25446.62.255.25532,766
12746.63.0.0/1746.63.0.1 to 46.63.127.25446.63.127.25532,766
12846.63.128.0/1746.63.128.1 to 46.63.255.25446.63.255.25532,766

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.