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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.

Network50.0.0.0/8
Usable hosts16,777,214
Subnet mask255.0.0.0
Addresses16,777,216
Network address
50.0.0.0
Broadcast address
50.255.255.255
First usable
50.0.0.1
Last usable
50.255.255.254
Usable hosts
16,777,214 (16,777,216 less the network and broadcast addresses)
Subnet mask
255.0.0.0
Wildcard mask
0.255.255.255 (Cisco ACLs, OSPF)
Prefix length
/8
Type
Public public
Old class
A (default /8)
As numbers
Hex 32000000 · Integer 838860800 to 855638015
Reverse DNS zone
50.in-addr.arpa
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address00110010..00000000.00000000.0000000050.0.0.0
Subnet mask11111111..00000000.00000000.00000000255.0.0.0
Network00110010..00000000.00000000.0000000050.0.0.0
Broadcast00110010..11111111.11111111.1111111150.255.255.255
Split into smaller subnets/20
/9 (2)/10 (4)/11 (8)/12 (16)/13 (32)/14 (64)/15 (128)/16 (256)/17 (512)/18 (1,024)/19 (2,048)/20 (4,096)

50.0.0.0/8 makes 4,096 subnets of /20; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
150.0.0.0/2050.0.0.1 to 50.0.15.25450.0.15.2554,094
250.0.16.0/2050.0.16.1 to 50.0.31.25450.0.31.2554,094
350.0.32.0/2050.0.32.1 to 50.0.47.25450.0.47.2554,094
450.0.48.0/2050.0.48.1 to 50.0.63.25450.0.63.2554,094
550.0.64.0/2050.0.64.1 to 50.0.79.25450.0.79.2554,094
650.0.80.0/2050.0.80.1 to 50.0.95.25450.0.95.2554,094
750.0.96.0/2050.0.96.1 to 50.0.111.25450.0.111.2554,094
850.0.112.0/2050.0.112.1 to 50.0.127.25450.0.127.2554,094
950.0.128.0/2050.0.128.1 to 50.0.143.25450.0.143.2554,094
1050.0.144.0/2050.0.144.1 to 50.0.159.25450.0.159.2554,094
1150.0.160.0/2050.0.160.1 to 50.0.175.25450.0.175.2554,094
1250.0.176.0/2050.0.176.1 to 50.0.191.25450.0.191.2554,094
1350.0.192.0/2050.0.192.1 to 50.0.207.25450.0.207.2554,094
1450.0.208.0/2050.0.208.1 to 50.0.223.25450.0.223.2554,094
1550.0.224.0/2050.0.224.1 to 50.0.239.25450.0.239.2554,094
1650.0.240.0/2050.0.240.1 to 50.0.255.25450.0.255.2554,094
1750.1.0.0/2050.1.0.1 to 50.1.15.25450.1.15.2554,094
1850.1.16.0/2050.1.16.1 to 50.1.31.25450.1.31.2554,094
1950.1.32.0/2050.1.32.1 to 50.1.47.25450.1.47.2554,094
2050.1.48.0/2050.1.48.1 to 50.1.63.25450.1.63.2554,094
2150.1.64.0/2050.1.64.1 to 50.1.79.25450.1.79.2554,094
2250.1.80.0/2050.1.80.1 to 50.1.95.25450.1.95.2554,094
2350.1.96.0/2050.1.96.1 to 50.1.111.25450.1.111.2554,094
2450.1.112.0/2050.1.112.1 to 50.1.127.25450.1.127.2554,094
2550.1.128.0/2050.1.128.1 to 50.1.143.25450.1.143.2554,094
2650.1.144.0/2050.1.144.1 to 50.1.159.25450.1.159.2554,094
2750.1.160.0/2050.1.160.1 to 50.1.175.25450.1.175.2554,094
2850.1.176.0/2050.1.176.1 to 50.1.191.25450.1.191.2554,094
2950.1.192.0/2050.1.192.1 to 50.1.207.25450.1.207.2554,094
3050.1.208.0/2050.1.208.1 to 50.1.223.25450.1.223.2554,094
3150.1.224.0/2050.1.224.1 to 50.1.239.25450.1.239.2554,094
3250.1.240.0/2050.1.240.1 to 50.1.255.25450.1.255.2554,094
3350.2.0.0/2050.2.0.1 to 50.2.15.25450.2.15.2554,094
3450.2.16.0/2050.2.16.1 to 50.2.31.25450.2.31.2554,094
3550.2.32.0/2050.2.32.1 to 50.2.47.25450.2.47.2554,094
3650.2.48.0/2050.2.48.1 to 50.2.63.25450.2.63.2554,094
3750.2.64.0/2050.2.64.1 to 50.2.79.25450.2.79.2554,094
3850.2.80.0/2050.2.80.1 to 50.2.95.25450.2.95.2554,094
3950.2.96.0/2050.2.96.1 to 50.2.111.25450.2.111.2554,094
4050.2.112.0/2050.2.112.1 to 50.2.127.25450.2.127.2554,094
4150.2.128.0/2050.2.128.1 to 50.2.143.25450.2.143.2554,094
4250.2.144.0/2050.2.144.1 to 50.2.159.25450.2.159.2554,094
4350.2.160.0/2050.2.160.1 to 50.2.175.25450.2.175.2554,094
4450.2.176.0/2050.2.176.1 to 50.2.191.25450.2.191.2554,094
4550.2.192.0/2050.2.192.1 to 50.2.207.25450.2.207.2554,094
4650.2.208.0/2050.2.208.1 to 50.2.223.25450.2.223.2554,094
4750.2.224.0/2050.2.224.1 to 50.2.239.25450.2.239.2554,094
4850.2.240.0/2050.2.240.1 to 50.2.255.25450.2.255.2554,094
4950.3.0.0/2050.3.0.1 to 50.3.15.25450.3.15.2554,094
5050.3.16.0/2050.3.16.1 to 50.3.31.25450.3.31.2554,094
5150.3.32.0/2050.3.32.1 to 50.3.47.25450.3.47.2554,094
5250.3.48.0/2050.3.48.1 to 50.3.63.25450.3.63.2554,094
5350.3.64.0/2050.3.64.1 to 50.3.79.25450.3.79.2554,094
5450.3.80.0/2050.3.80.1 to 50.3.95.25450.3.95.2554,094
5550.3.96.0/2050.3.96.1 to 50.3.111.25450.3.111.2554,094
5650.3.112.0/2050.3.112.1 to 50.3.127.25450.3.127.2554,094
5750.3.128.0/2050.3.128.1 to 50.3.143.25450.3.143.2554,094
5850.3.144.0/2050.3.144.1 to 50.3.159.25450.3.159.2554,094
5950.3.160.0/2050.3.160.1 to 50.3.175.25450.3.175.2554,094
6050.3.176.0/2050.3.176.1 to 50.3.191.25450.3.191.2554,094
6150.3.192.0/2050.3.192.1 to 50.3.207.25450.3.207.2554,094
6250.3.208.0/2050.3.208.1 to 50.3.223.25450.3.223.2554,094
6350.3.224.0/2050.3.224.1 to 50.3.239.25450.3.239.2554,094
6450.3.240.0/2050.3.240.1 to 50.3.255.25450.3.255.2554,094
6550.4.0.0/2050.4.0.1 to 50.4.15.25450.4.15.2554,094
6650.4.16.0/2050.4.16.1 to 50.4.31.25450.4.31.2554,094
6750.4.32.0/2050.4.32.1 to 50.4.47.25450.4.47.2554,094
6850.4.48.0/2050.4.48.1 to 50.4.63.25450.4.63.2554,094
6950.4.64.0/2050.4.64.1 to 50.4.79.25450.4.79.2554,094
7050.4.80.0/2050.4.80.1 to 50.4.95.25450.4.95.2554,094
7150.4.96.0/2050.4.96.1 to 50.4.111.25450.4.111.2554,094
7250.4.112.0/2050.4.112.1 to 50.4.127.25450.4.127.2554,094
7350.4.128.0/2050.4.128.1 to 50.4.143.25450.4.143.2554,094
7450.4.144.0/2050.4.144.1 to 50.4.159.25450.4.159.2554,094
7550.4.160.0/2050.4.160.1 to 50.4.175.25450.4.175.2554,094
7650.4.176.0/2050.4.176.1 to 50.4.191.25450.4.191.2554,094
7750.4.192.0/2050.4.192.1 to 50.4.207.25450.4.207.2554,094
7850.4.208.0/2050.4.208.1 to 50.4.223.25450.4.223.2554,094
7950.4.224.0/2050.4.224.1 to 50.4.239.25450.4.239.2554,094
8050.4.240.0/2050.4.240.1 to 50.4.255.25450.4.255.2554,094
8150.5.0.0/2050.5.0.1 to 50.5.15.25450.5.15.2554,094
8250.5.16.0/2050.5.16.1 to 50.5.31.25450.5.31.2554,094
8350.5.32.0/2050.5.32.1 to 50.5.47.25450.5.47.2554,094
8450.5.48.0/2050.5.48.1 to 50.5.63.25450.5.63.2554,094
8550.5.64.0/2050.5.64.1 to 50.5.79.25450.5.79.2554,094
8650.5.80.0/2050.5.80.1 to 50.5.95.25450.5.95.2554,094
8750.5.96.0/2050.5.96.1 to 50.5.111.25450.5.111.2554,094
8850.5.112.0/2050.5.112.1 to 50.5.127.25450.5.127.2554,094
8950.5.128.0/2050.5.128.1 to 50.5.143.25450.5.143.2554,094
9050.5.144.0/2050.5.144.1 to 50.5.159.25450.5.159.2554,094
9150.5.160.0/2050.5.160.1 to 50.5.175.25450.5.175.2554,094
9250.5.176.0/2050.5.176.1 to 50.5.191.25450.5.191.2554,094
9350.5.192.0/2050.5.192.1 to 50.5.207.25450.5.207.2554,094
9450.5.208.0/2050.5.208.1 to 50.5.223.25450.5.223.2554,094
9550.5.224.0/2050.5.224.1 to 50.5.239.25450.5.239.2554,094
9650.5.240.0/2050.5.240.1 to 50.5.255.25450.5.255.2554,094
9750.6.0.0/2050.6.0.1 to 50.6.15.25450.6.15.2554,094
9850.6.16.0/2050.6.16.1 to 50.6.31.25450.6.31.2554,094
9950.6.32.0/2050.6.32.1 to 50.6.47.25450.6.47.2554,094
10050.6.48.0/2050.6.48.1 to 50.6.63.25450.6.63.2554,094
10150.6.64.0/2050.6.64.1 to 50.6.79.25450.6.79.2554,094
10250.6.80.0/2050.6.80.1 to 50.6.95.25450.6.95.2554,094
10350.6.96.0/2050.6.96.1 to 50.6.111.25450.6.111.2554,094
10450.6.112.0/2050.6.112.1 to 50.6.127.25450.6.127.2554,094
10550.6.128.0/2050.6.128.1 to 50.6.143.25450.6.143.2554,094
10650.6.144.0/2050.6.144.1 to 50.6.159.25450.6.159.2554,094
10750.6.160.0/2050.6.160.1 to 50.6.175.25450.6.175.2554,094
10850.6.176.0/2050.6.176.1 to 50.6.191.25450.6.191.2554,094
10950.6.192.0/2050.6.192.1 to 50.6.207.25450.6.207.2554,094
11050.6.208.0/2050.6.208.1 to 50.6.223.25450.6.223.2554,094
11150.6.224.0/2050.6.224.1 to 50.6.239.25450.6.239.2554,094
11250.6.240.0/2050.6.240.1 to 50.6.255.25450.6.255.2554,094
11350.7.0.0/2050.7.0.1 to 50.7.15.25450.7.15.2554,094
11450.7.16.0/2050.7.16.1 to 50.7.31.25450.7.31.2554,094
11550.7.32.0/2050.7.32.1 to 50.7.47.25450.7.47.2554,094
11650.7.48.0/2050.7.48.1 to 50.7.63.25450.7.63.2554,094
11750.7.64.0/2050.7.64.1 to 50.7.79.25450.7.79.2554,094
11850.7.80.0/2050.7.80.1 to 50.7.95.25450.7.95.2554,094
11950.7.96.0/2050.7.96.1 to 50.7.111.25450.7.111.2554,094
12050.7.112.0/2050.7.112.1 to 50.7.127.25450.7.127.2554,094
12150.7.128.0/2050.7.128.1 to 50.7.143.25450.7.143.2554,094
12250.7.144.0/2050.7.144.1 to 50.7.159.25450.7.159.2554,094
12350.7.160.0/2050.7.160.1 to 50.7.175.25450.7.175.2554,094
12450.7.176.0/2050.7.176.1 to 50.7.191.25450.7.191.2554,094
12550.7.192.0/2050.7.192.1 to 50.7.207.25450.7.207.2554,094
12650.7.208.0/2050.7.208.1 to 50.7.223.25450.7.223.2554,094
12750.7.224.0/2050.7.224.1 to 50.7.239.25450.7.239.2554,094
12850.7.240.0/2050.7.240.1 to 50.7.255.25450.7.255.2554,094
12950.8.0.0/2050.8.0.1 to 50.8.15.25450.8.15.2554,094
13050.8.16.0/2050.8.16.1 to 50.8.31.25450.8.31.2554,094
13150.8.32.0/2050.8.32.1 to 50.8.47.25450.8.47.2554,094
13250.8.48.0/2050.8.48.1 to 50.8.63.25450.8.63.2554,094
13350.8.64.0/2050.8.64.1 to 50.8.79.25450.8.79.2554,094
13450.8.80.0/2050.8.80.1 to 50.8.95.25450.8.95.2554,094
13550.8.96.0/2050.8.96.1 to 50.8.111.25450.8.111.2554,094
13650.8.112.0/2050.8.112.1 to 50.8.127.25450.8.127.2554,094
13750.8.128.0/2050.8.128.1 to 50.8.143.25450.8.143.2554,094
13850.8.144.0/2050.8.144.1 to 50.8.159.25450.8.159.2554,094
13950.8.160.0/2050.8.160.1 to 50.8.175.25450.8.175.2554,094
14050.8.176.0/2050.8.176.1 to 50.8.191.25450.8.191.2554,094
14150.8.192.0/2050.8.192.1 to 50.8.207.25450.8.207.2554,094
14250.8.208.0/2050.8.208.1 to 50.8.223.25450.8.223.2554,094
14350.8.224.0/2050.8.224.1 to 50.8.239.25450.8.239.2554,094
14450.8.240.0/2050.8.240.1 to 50.8.255.25450.8.255.2554,094
14550.9.0.0/2050.9.0.1 to 50.9.15.25450.9.15.2554,094
14650.9.16.0/2050.9.16.1 to 50.9.31.25450.9.31.2554,094
14750.9.32.0/2050.9.32.1 to 50.9.47.25450.9.47.2554,094
14850.9.48.0/2050.9.48.1 to 50.9.63.25450.9.63.2554,094
14950.9.64.0/2050.9.64.1 to 50.9.79.25450.9.79.2554,094
15050.9.80.0/2050.9.80.1 to 50.9.95.25450.9.95.2554,094
15150.9.96.0/2050.9.96.1 to 50.9.111.25450.9.111.2554,094
15250.9.112.0/2050.9.112.1 to 50.9.127.25450.9.127.2554,094
15350.9.128.0/2050.9.128.1 to 50.9.143.25450.9.143.2554,094
15450.9.144.0/2050.9.144.1 to 50.9.159.25450.9.159.2554,094
15550.9.160.0/2050.9.160.1 to 50.9.175.25450.9.175.2554,094
15650.9.176.0/2050.9.176.1 to 50.9.191.25450.9.191.2554,094
15750.9.192.0/2050.9.192.1 to 50.9.207.25450.9.207.2554,094
15850.9.208.0/2050.9.208.1 to 50.9.223.25450.9.223.2554,094
15950.9.224.0/2050.9.224.1 to 50.9.239.25450.9.239.2554,094
16050.9.240.0/2050.9.240.1 to 50.9.255.25450.9.255.2554,094
16150.10.0.0/2050.10.0.1 to 50.10.15.25450.10.15.2554,094
16250.10.16.0/2050.10.16.1 to 50.10.31.25450.10.31.2554,094
16350.10.32.0/2050.10.32.1 to 50.10.47.25450.10.47.2554,094
16450.10.48.0/2050.10.48.1 to 50.10.63.25450.10.63.2554,094
16550.10.64.0/2050.10.64.1 to 50.10.79.25450.10.79.2554,094
16650.10.80.0/2050.10.80.1 to 50.10.95.25450.10.95.2554,094
16750.10.96.0/2050.10.96.1 to 50.10.111.25450.10.111.2554,094
16850.10.112.0/2050.10.112.1 to 50.10.127.25450.10.127.2554,094
16950.10.128.0/2050.10.128.1 to 50.10.143.25450.10.143.2554,094
17050.10.144.0/2050.10.144.1 to 50.10.159.25450.10.159.2554,094
17150.10.160.0/2050.10.160.1 to 50.10.175.25450.10.175.2554,094
17250.10.176.0/2050.10.176.1 to 50.10.191.25450.10.191.2554,094
17350.10.192.0/2050.10.192.1 to 50.10.207.25450.10.207.2554,094
17450.10.208.0/2050.10.208.1 to 50.10.223.25450.10.223.2554,094
17550.10.224.0/2050.10.224.1 to 50.10.239.25450.10.239.2554,094
17650.10.240.0/2050.10.240.1 to 50.10.255.25450.10.255.2554,094
17750.11.0.0/2050.11.0.1 to 50.11.15.25450.11.15.2554,094
17850.11.16.0/2050.11.16.1 to 50.11.31.25450.11.31.2554,094
17950.11.32.0/2050.11.32.1 to 50.11.47.25450.11.47.2554,094
18050.11.48.0/2050.11.48.1 to 50.11.63.25450.11.63.2554,094
18150.11.64.0/2050.11.64.1 to 50.11.79.25450.11.79.2554,094
18250.11.80.0/2050.11.80.1 to 50.11.95.25450.11.95.2554,094
18350.11.96.0/2050.11.96.1 to 50.11.111.25450.11.111.2554,094
18450.11.112.0/2050.11.112.1 to 50.11.127.25450.11.127.2554,094
18550.11.128.0/2050.11.128.1 to 50.11.143.25450.11.143.2554,094
18650.11.144.0/2050.11.144.1 to 50.11.159.25450.11.159.2554,094
18750.11.160.0/2050.11.160.1 to 50.11.175.25450.11.175.2554,094
18850.11.176.0/2050.11.176.1 to 50.11.191.25450.11.191.2554,094
18950.11.192.0/2050.11.192.1 to 50.11.207.25450.11.207.2554,094
19050.11.208.0/2050.11.208.1 to 50.11.223.25450.11.223.2554,094
19150.11.224.0/2050.11.224.1 to 50.11.239.25450.11.239.2554,094
19250.11.240.0/2050.11.240.1 to 50.11.255.25450.11.255.2554,094
19350.12.0.0/2050.12.0.1 to 50.12.15.25450.12.15.2554,094
19450.12.16.0/2050.12.16.1 to 50.12.31.25450.12.31.2554,094
19550.12.32.0/2050.12.32.1 to 50.12.47.25450.12.47.2554,094
19650.12.48.0/2050.12.48.1 to 50.12.63.25450.12.63.2554,094
19750.12.64.0/2050.12.64.1 to 50.12.79.25450.12.79.2554,094
19850.12.80.0/2050.12.80.1 to 50.12.95.25450.12.95.2554,094
19950.12.96.0/2050.12.96.1 to 50.12.111.25450.12.111.2554,094
20050.12.112.0/2050.12.112.1 to 50.12.127.25450.12.127.2554,094
20150.12.128.0/2050.12.128.1 to 50.12.143.25450.12.143.2554,094
20250.12.144.0/2050.12.144.1 to 50.12.159.25450.12.159.2554,094
20350.12.160.0/2050.12.160.1 to 50.12.175.25450.12.175.2554,094
20450.12.176.0/2050.12.176.1 to 50.12.191.25450.12.191.2554,094
20550.12.192.0/2050.12.192.1 to 50.12.207.25450.12.207.2554,094
20650.12.208.0/2050.12.208.1 to 50.12.223.25450.12.223.2554,094
20750.12.224.0/2050.12.224.1 to 50.12.239.25450.12.239.2554,094
20850.12.240.0/2050.12.240.1 to 50.12.255.25450.12.255.2554,094
20950.13.0.0/2050.13.0.1 to 50.13.15.25450.13.15.2554,094
21050.13.16.0/2050.13.16.1 to 50.13.31.25450.13.31.2554,094
21150.13.32.0/2050.13.32.1 to 50.13.47.25450.13.47.2554,094
21250.13.48.0/2050.13.48.1 to 50.13.63.25450.13.63.2554,094
21350.13.64.0/2050.13.64.1 to 50.13.79.25450.13.79.2554,094
21450.13.80.0/2050.13.80.1 to 50.13.95.25450.13.95.2554,094
21550.13.96.0/2050.13.96.1 to 50.13.111.25450.13.111.2554,094
21650.13.112.0/2050.13.112.1 to 50.13.127.25450.13.127.2554,094
21750.13.128.0/2050.13.128.1 to 50.13.143.25450.13.143.2554,094
21850.13.144.0/2050.13.144.1 to 50.13.159.25450.13.159.2554,094
21950.13.160.0/2050.13.160.1 to 50.13.175.25450.13.175.2554,094
22050.13.176.0/2050.13.176.1 to 50.13.191.25450.13.191.2554,094
22150.13.192.0/2050.13.192.1 to 50.13.207.25450.13.207.2554,094
22250.13.208.0/2050.13.208.1 to 50.13.223.25450.13.223.2554,094
22350.13.224.0/2050.13.224.1 to 50.13.239.25450.13.239.2554,094
22450.13.240.0/2050.13.240.1 to 50.13.255.25450.13.255.2554,094
22550.14.0.0/2050.14.0.1 to 50.14.15.25450.14.15.2554,094
22650.14.16.0/2050.14.16.1 to 50.14.31.25450.14.31.2554,094
22750.14.32.0/2050.14.32.1 to 50.14.47.25450.14.47.2554,094
22850.14.48.0/2050.14.48.1 to 50.14.63.25450.14.63.2554,094
22950.14.64.0/2050.14.64.1 to 50.14.79.25450.14.79.2554,094
23050.14.80.0/2050.14.80.1 to 50.14.95.25450.14.95.2554,094
23150.14.96.0/2050.14.96.1 to 50.14.111.25450.14.111.2554,094
23250.14.112.0/2050.14.112.1 to 50.14.127.25450.14.127.2554,094
23350.14.128.0/2050.14.128.1 to 50.14.143.25450.14.143.2554,094
23450.14.144.0/2050.14.144.1 to 50.14.159.25450.14.159.2554,094
23550.14.160.0/2050.14.160.1 to 50.14.175.25450.14.175.2554,094
23650.14.176.0/2050.14.176.1 to 50.14.191.25450.14.191.2554,094
23750.14.192.0/2050.14.192.1 to 50.14.207.25450.14.207.2554,094
23850.14.208.0/2050.14.208.1 to 50.14.223.25450.14.223.2554,094
23950.14.224.0/2050.14.224.1 to 50.14.239.25450.14.239.2554,094
24050.14.240.0/2050.14.240.1 to 50.14.255.25450.14.255.2554,094
24150.15.0.0/2050.15.0.1 to 50.15.15.25450.15.15.2554,094
24250.15.16.0/2050.15.16.1 to 50.15.31.25450.15.31.2554,094
24350.15.32.0/2050.15.32.1 to 50.15.47.25450.15.47.2554,094
24450.15.48.0/2050.15.48.1 to 50.15.63.25450.15.63.2554,094
24550.15.64.0/2050.15.64.1 to 50.15.79.25450.15.79.2554,094
24650.15.80.0/2050.15.80.1 to 50.15.95.25450.15.95.2554,094
24750.15.96.0/2050.15.96.1 to 50.15.111.25450.15.111.2554,094
24850.15.112.0/2050.15.112.1 to 50.15.127.25450.15.127.2554,094
24950.15.128.0/2050.15.128.1 to 50.15.143.25450.15.143.2554,094
25050.15.144.0/2050.15.144.1 to 50.15.159.25450.15.159.2554,094
25150.15.160.0/2050.15.160.1 to 50.15.175.25450.15.175.2554,094
25250.15.176.0/2050.15.176.1 to 50.15.191.25450.15.191.2554,094
25350.15.192.0/2050.15.192.1 to 50.15.207.25450.15.207.2554,094
25450.15.208.0/2050.15.208.1 to 50.15.223.25450.15.223.2554,094
25550.15.224.0/2050.15.224.1 to 50.15.239.25450.15.239.2554,094
25650.15.240.0/2050.15.240.1 to 50.15.255.25450.15.255.2554,094

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.