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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.

Network97.124.0.0/15
Usable hosts131,070
Subnet mask255.254.0.0
Addresses131,072
Network address
97.124.0.0
Broadcast address
97.125.255.255
First usable
97.124.0.1
Last usable
97.125.255.254
Usable hosts
131,070 (131,072 less the network and broadcast addresses)
Subnet mask
255.254.0.0
Wildcard mask
0.1.255.255 (Cisco ACLs, OSPF)
Prefix length
/15
Type
Public public
Old class
A (default /8)
As numbers
Hex 617C0000 · Integer 1635516416 to 1635647487
Reverse DNS zones
124.97.in-addr.arpa
125.97.in-addr.arpa
/15 is not on a 8-bit boundary, so it takes 2 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address01100001.01111100.00000000.0000000097.124.0.0
Subnet mask11111111.11111110.00000000.00000000255.254.0.0
Network01100001.01111100.00000000.0000000097.124.0.0
Broadcast01100001.01111101.11111111.1111111197.125.255.255
Split into smaller subnets/27
/16 (2)/17 (4)/18 (8)/19 (16)/20 (32)/21 (64)/22 (128)/23 (256)/24 (512)/25 (1,024)/26 (2,048)/27 (4,096)

97.124.0.0/15 makes 4,096 subnets of /27; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
197.124.0.0/2797.124.0.1 to 97.124.0.3097.124.0.3130
297.124.0.32/2797.124.0.33 to 97.124.0.6297.124.0.6330
397.124.0.64/2797.124.0.65 to 97.124.0.9497.124.0.9530
497.124.0.96/2797.124.0.97 to 97.124.0.12697.124.0.12730
597.124.0.128/2797.124.0.129 to 97.124.0.15897.124.0.15930
697.124.0.160/2797.124.0.161 to 97.124.0.19097.124.0.19130
797.124.0.192/2797.124.0.193 to 97.124.0.22297.124.0.22330
897.124.0.224/2797.124.0.225 to 97.124.0.25497.124.0.25530
997.124.1.0/2797.124.1.1 to 97.124.1.3097.124.1.3130
1097.124.1.32/2797.124.1.33 to 97.124.1.6297.124.1.6330
1197.124.1.64/2797.124.1.65 to 97.124.1.9497.124.1.9530
1297.124.1.96/2797.124.1.97 to 97.124.1.12697.124.1.12730
1397.124.1.128/2797.124.1.129 to 97.124.1.15897.124.1.15930
1497.124.1.160/2797.124.1.161 to 97.124.1.19097.124.1.19130
1597.124.1.192/2797.124.1.193 to 97.124.1.22297.124.1.22330
1697.124.1.224/2797.124.1.225 to 97.124.1.25497.124.1.25530
1797.124.2.0/2797.124.2.1 to 97.124.2.3097.124.2.3130
1897.124.2.32/2797.124.2.33 to 97.124.2.6297.124.2.6330
1997.124.2.64/2797.124.2.65 to 97.124.2.9497.124.2.9530
2097.124.2.96/2797.124.2.97 to 97.124.2.12697.124.2.12730
2197.124.2.128/2797.124.2.129 to 97.124.2.15897.124.2.15930
2297.124.2.160/2797.124.2.161 to 97.124.2.19097.124.2.19130
2397.124.2.192/2797.124.2.193 to 97.124.2.22297.124.2.22330
2497.124.2.224/2797.124.2.225 to 97.124.2.25497.124.2.25530
2597.124.3.0/2797.124.3.1 to 97.124.3.3097.124.3.3130
2697.124.3.32/2797.124.3.33 to 97.124.3.6297.124.3.6330
2797.124.3.64/2797.124.3.65 to 97.124.3.9497.124.3.9530
2897.124.3.96/2797.124.3.97 to 97.124.3.12697.124.3.12730
2997.124.3.128/2797.124.3.129 to 97.124.3.15897.124.3.15930
3097.124.3.160/2797.124.3.161 to 97.124.3.19097.124.3.19130
3197.124.3.192/2797.124.3.193 to 97.124.3.22297.124.3.22330
3297.124.3.224/2797.124.3.225 to 97.124.3.25497.124.3.25530
3397.124.4.0/2797.124.4.1 to 97.124.4.3097.124.4.3130
3497.124.4.32/2797.124.4.33 to 97.124.4.6297.124.4.6330
3597.124.4.64/2797.124.4.65 to 97.124.4.9497.124.4.9530
3697.124.4.96/2797.124.4.97 to 97.124.4.12697.124.4.12730
3797.124.4.128/2797.124.4.129 to 97.124.4.15897.124.4.15930
3897.124.4.160/2797.124.4.161 to 97.124.4.19097.124.4.19130
3997.124.4.192/2797.124.4.193 to 97.124.4.22297.124.4.22330
4097.124.4.224/2797.124.4.225 to 97.124.4.25497.124.4.25530
4197.124.5.0/2797.124.5.1 to 97.124.5.3097.124.5.3130
4297.124.5.32/2797.124.5.33 to 97.124.5.6297.124.5.6330
4397.124.5.64/2797.124.5.65 to 97.124.5.9497.124.5.9530
4497.124.5.96/2797.124.5.97 to 97.124.5.12697.124.5.12730
4597.124.5.128/2797.124.5.129 to 97.124.5.15897.124.5.15930
4697.124.5.160/2797.124.5.161 to 97.124.5.19097.124.5.19130
4797.124.5.192/2797.124.5.193 to 97.124.5.22297.124.5.22330
4897.124.5.224/2797.124.5.225 to 97.124.5.25497.124.5.25530
4997.124.6.0/2797.124.6.1 to 97.124.6.3097.124.6.3130
5097.124.6.32/2797.124.6.33 to 97.124.6.6297.124.6.6330
5197.124.6.64/2797.124.6.65 to 97.124.6.9497.124.6.9530
5297.124.6.96/2797.124.6.97 to 97.124.6.12697.124.6.12730
5397.124.6.128/2797.124.6.129 to 97.124.6.15897.124.6.15930
5497.124.6.160/2797.124.6.161 to 97.124.6.19097.124.6.19130
5597.124.6.192/2797.124.6.193 to 97.124.6.22297.124.6.22330
5697.124.6.224/2797.124.6.225 to 97.124.6.25497.124.6.25530
5797.124.7.0/2797.124.7.1 to 97.124.7.3097.124.7.3130
5897.124.7.32/2797.124.7.33 to 97.124.7.6297.124.7.6330
5997.124.7.64/2797.124.7.65 to 97.124.7.9497.124.7.9530
6097.124.7.96/2797.124.7.97 to 97.124.7.12697.124.7.12730
6197.124.7.128/2797.124.7.129 to 97.124.7.15897.124.7.15930
6297.124.7.160/2797.124.7.161 to 97.124.7.19097.124.7.19130
6397.124.7.192/2797.124.7.193 to 97.124.7.22297.124.7.22330
6497.124.7.224/2797.124.7.225 to 97.124.7.25497.124.7.25530
6597.124.8.0/2797.124.8.1 to 97.124.8.3097.124.8.3130
6697.124.8.32/2797.124.8.33 to 97.124.8.6297.124.8.6330
6797.124.8.64/2797.124.8.65 to 97.124.8.9497.124.8.9530
6897.124.8.96/2797.124.8.97 to 97.124.8.12697.124.8.12730
6997.124.8.128/2797.124.8.129 to 97.124.8.15897.124.8.15930
7097.124.8.160/2797.124.8.161 to 97.124.8.19097.124.8.19130
7197.124.8.192/2797.124.8.193 to 97.124.8.22297.124.8.22330
7297.124.8.224/2797.124.8.225 to 97.124.8.25497.124.8.25530
7397.124.9.0/2797.124.9.1 to 97.124.9.3097.124.9.3130
7497.124.9.32/2797.124.9.33 to 97.124.9.6297.124.9.6330
7597.124.9.64/2797.124.9.65 to 97.124.9.9497.124.9.9530
7697.124.9.96/2797.124.9.97 to 97.124.9.12697.124.9.12730
7797.124.9.128/2797.124.9.129 to 97.124.9.15897.124.9.15930
7897.124.9.160/2797.124.9.161 to 97.124.9.19097.124.9.19130
7997.124.9.192/2797.124.9.193 to 97.124.9.22297.124.9.22330
8097.124.9.224/2797.124.9.225 to 97.124.9.25497.124.9.25530
8197.124.10.0/2797.124.10.1 to 97.124.10.3097.124.10.3130
8297.124.10.32/2797.124.10.33 to 97.124.10.6297.124.10.6330
8397.124.10.64/2797.124.10.65 to 97.124.10.9497.124.10.9530
8497.124.10.96/2797.124.10.97 to 97.124.10.12697.124.10.12730
8597.124.10.128/2797.124.10.129 to 97.124.10.15897.124.10.15930
8697.124.10.160/2797.124.10.161 to 97.124.10.19097.124.10.19130
8797.124.10.192/2797.124.10.193 to 97.124.10.22297.124.10.22330
8897.124.10.224/2797.124.10.225 to 97.124.10.25497.124.10.25530
8997.124.11.0/2797.124.11.1 to 97.124.11.3097.124.11.3130
9097.124.11.32/2797.124.11.33 to 97.124.11.6297.124.11.6330
9197.124.11.64/2797.124.11.65 to 97.124.11.9497.124.11.9530
9297.124.11.96/2797.124.11.97 to 97.124.11.12697.124.11.12730
9397.124.11.128/2797.124.11.129 to 97.124.11.15897.124.11.15930
9497.124.11.160/2797.124.11.161 to 97.124.11.19097.124.11.19130
9597.124.11.192/2797.124.11.193 to 97.124.11.22297.124.11.22330
9697.124.11.224/2797.124.11.225 to 97.124.11.25497.124.11.25530
9797.124.12.0/2797.124.12.1 to 97.124.12.3097.124.12.3130
9897.124.12.32/2797.124.12.33 to 97.124.12.6297.124.12.6330
9997.124.12.64/2797.124.12.65 to 97.124.12.9497.124.12.9530
10097.124.12.96/2797.124.12.97 to 97.124.12.12697.124.12.12730
10197.124.12.128/2797.124.12.129 to 97.124.12.15897.124.12.15930
10297.124.12.160/2797.124.12.161 to 97.124.12.19097.124.12.19130
10397.124.12.192/2797.124.12.193 to 97.124.12.22297.124.12.22330
10497.124.12.224/2797.124.12.225 to 97.124.12.25497.124.12.25530
10597.124.13.0/2797.124.13.1 to 97.124.13.3097.124.13.3130
10697.124.13.32/2797.124.13.33 to 97.124.13.6297.124.13.6330
10797.124.13.64/2797.124.13.65 to 97.124.13.9497.124.13.9530
10897.124.13.96/2797.124.13.97 to 97.124.13.12697.124.13.12730
10997.124.13.128/2797.124.13.129 to 97.124.13.15897.124.13.15930
11097.124.13.160/2797.124.13.161 to 97.124.13.19097.124.13.19130
11197.124.13.192/2797.124.13.193 to 97.124.13.22297.124.13.22330
11297.124.13.224/2797.124.13.225 to 97.124.13.25497.124.13.25530
11397.124.14.0/2797.124.14.1 to 97.124.14.3097.124.14.3130
11497.124.14.32/2797.124.14.33 to 97.124.14.6297.124.14.6330
11597.124.14.64/2797.124.14.65 to 97.124.14.9497.124.14.9530
11697.124.14.96/2797.124.14.97 to 97.124.14.12697.124.14.12730
11797.124.14.128/2797.124.14.129 to 97.124.14.15897.124.14.15930
11897.124.14.160/2797.124.14.161 to 97.124.14.19097.124.14.19130
11997.124.14.192/2797.124.14.193 to 97.124.14.22297.124.14.22330
12097.124.14.224/2797.124.14.225 to 97.124.14.25497.124.14.25530
12197.124.15.0/2797.124.15.1 to 97.124.15.3097.124.15.3130
12297.124.15.32/2797.124.15.33 to 97.124.15.6297.124.15.6330
12397.124.15.64/2797.124.15.65 to 97.124.15.9497.124.15.9530
12497.124.15.96/2797.124.15.97 to 97.124.15.12697.124.15.12730
12597.124.15.128/2797.124.15.129 to 97.124.15.15897.124.15.15930
12697.124.15.160/2797.124.15.161 to 97.124.15.19097.124.15.19130
12797.124.15.192/2797.124.15.193 to 97.124.15.22297.124.15.22330
12897.124.15.224/2797.124.15.225 to 97.124.15.25497.124.15.25530
12997.124.16.0/2797.124.16.1 to 97.124.16.3097.124.16.3130
13097.124.16.32/2797.124.16.33 to 97.124.16.6297.124.16.6330
13197.124.16.64/2797.124.16.65 to 97.124.16.9497.124.16.9530
13297.124.16.96/2797.124.16.97 to 97.124.16.12697.124.16.12730
13397.124.16.128/2797.124.16.129 to 97.124.16.15897.124.16.15930
13497.124.16.160/2797.124.16.161 to 97.124.16.19097.124.16.19130
13597.124.16.192/2797.124.16.193 to 97.124.16.22297.124.16.22330
13697.124.16.224/2797.124.16.225 to 97.124.16.25497.124.16.25530
13797.124.17.0/2797.124.17.1 to 97.124.17.3097.124.17.3130
13897.124.17.32/2797.124.17.33 to 97.124.17.6297.124.17.6330
13997.124.17.64/2797.124.17.65 to 97.124.17.9497.124.17.9530
14097.124.17.96/2797.124.17.97 to 97.124.17.12697.124.17.12730
14197.124.17.128/2797.124.17.129 to 97.124.17.15897.124.17.15930
14297.124.17.160/2797.124.17.161 to 97.124.17.19097.124.17.19130
14397.124.17.192/2797.124.17.193 to 97.124.17.22297.124.17.22330
14497.124.17.224/2797.124.17.225 to 97.124.17.25497.124.17.25530
14597.124.18.0/2797.124.18.1 to 97.124.18.3097.124.18.3130
14697.124.18.32/2797.124.18.33 to 97.124.18.6297.124.18.6330
14797.124.18.64/2797.124.18.65 to 97.124.18.9497.124.18.9530
14897.124.18.96/2797.124.18.97 to 97.124.18.12697.124.18.12730
14997.124.18.128/2797.124.18.129 to 97.124.18.15897.124.18.15930
15097.124.18.160/2797.124.18.161 to 97.124.18.19097.124.18.19130
15197.124.18.192/2797.124.18.193 to 97.124.18.22297.124.18.22330
15297.124.18.224/2797.124.18.225 to 97.124.18.25497.124.18.25530
15397.124.19.0/2797.124.19.1 to 97.124.19.3097.124.19.3130
15497.124.19.32/2797.124.19.33 to 97.124.19.6297.124.19.6330
15597.124.19.64/2797.124.19.65 to 97.124.19.9497.124.19.9530
15697.124.19.96/2797.124.19.97 to 97.124.19.12697.124.19.12730
15797.124.19.128/2797.124.19.129 to 97.124.19.15897.124.19.15930
15897.124.19.160/2797.124.19.161 to 97.124.19.19097.124.19.19130
15997.124.19.192/2797.124.19.193 to 97.124.19.22297.124.19.22330
16097.124.19.224/2797.124.19.225 to 97.124.19.25497.124.19.25530
16197.124.20.0/2797.124.20.1 to 97.124.20.3097.124.20.3130
16297.124.20.32/2797.124.20.33 to 97.124.20.6297.124.20.6330
16397.124.20.64/2797.124.20.65 to 97.124.20.9497.124.20.9530
16497.124.20.96/2797.124.20.97 to 97.124.20.12697.124.20.12730
16597.124.20.128/2797.124.20.129 to 97.124.20.15897.124.20.15930
16697.124.20.160/2797.124.20.161 to 97.124.20.19097.124.20.19130
16797.124.20.192/2797.124.20.193 to 97.124.20.22297.124.20.22330
16897.124.20.224/2797.124.20.225 to 97.124.20.25497.124.20.25530
16997.124.21.0/2797.124.21.1 to 97.124.21.3097.124.21.3130
17097.124.21.32/2797.124.21.33 to 97.124.21.6297.124.21.6330
17197.124.21.64/2797.124.21.65 to 97.124.21.9497.124.21.9530
17297.124.21.96/2797.124.21.97 to 97.124.21.12697.124.21.12730
17397.124.21.128/2797.124.21.129 to 97.124.21.15897.124.21.15930
17497.124.21.160/2797.124.21.161 to 97.124.21.19097.124.21.19130
17597.124.21.192/2797.124.21.193 to 97.124.21.22297.124.21.22330
17697.124.21.224/2797.124.21.225 to 97.124.21.25497.124.21.25530
17797.124.22.0/2797.124.22.1 to 97.124.22.3097.124.22.3130
17897.124.22.32/2797.124.22.33 to 97.124.22.6297.124.22.6330
17997.124.22.64/2797.124.22.65 to 97.124.22.9497.124.22.9530
18097.124.22.96/2797.124.22.97 to 97.124.22.12697.124.22.12730
18197.124.22.128/2797.124.22.129 to 97.124.22.15897.124.22.15930
18297.124.22.160/2797.124.22.161 to 97.124.22.19097.124.22.19130
18397.124.22.192/2797.124.22.193 to 97.124.22.22297.124.22.22330
18497.124.22.224/2797.124.22.225 to 97.124.22.25497.124.22.25530
18597.124.23.0/2797.124.23.1 to 97.124.23.3097.124.23.3130
18697.124.23.32/2797.124.23.33 to 97.124.23.6297.124.23.6330
18797.124.23.64/2797.124.23.65 to 97.124.23.9497.124.23.9530
18897.124.23.96/2797.124.23.97 to 97.124.23.12697.124.23.12730
18997.124.23.128/2797.124.23.129 to 97.124.23.15897.124.23.15930
19097.124.23.160/2797.124.23.161 to 97.124.23.19097.124.23.19130
19197.124.23.192/2797.124.23.193 to 97.124.23.22297.124.23.22330
19297.124.23.224/2797.124.23.225 to 97.124.23.25497.124.23.25530
19397.124.24.0/2797.124.24.1 to 97.124.24.3097.124.24.3130
19497.124.24.32/2797.124.24.33 to 97.124.24.6297.124.24.6330
19597.124.24.64/2797.124.24.65 to 97.124.24.9497.124.24.9530
19697.124.24.96/2797.124.24.97 to 97.124.24.12697.124.24.12730
19797.124.24.128/2797.124.24.129 to 97.124.24.15897.124.24.15930
19897.124.24.160/2797.124.24.161 to 97.124.24.19097.124.24.19130
19997.124.24.192/2797.124.24.193 to 97.124.24.22297.124.24.22330
20097.124.24.224/2797.124.24.225 to 97.124.24.25497.124.24.25530
20197.124.25.0/2797.124.25.1 to 97.124.25.3097.124.25.3130
20297.124.25.32/2797.124.25.33 to 97.124.25.6297.124.25.6330
20397.124.25.64/2797.124.25.65 to 97.124.25.9497.124.25.9530
20497.124.25.96/2797.124.25.97 to 97.124.25.12697.124.25.12730
20597.124.25.128/2797.124.25.129 to 97.124.25.15897.124.25.15930
20697.124.25.160/2797.124.25.161 to 97.124.25.19097.124.25.19130
20797.124.25.192/2797.124.25.193 to 97.124.25.22297.124.25.22330
20897.124.25.224/2797.124.25.225 to 97.124.25.25497.124.25.25530
20997.124.26.0/2797.124.26.1 to 97.124.26.3097.124.26.3130
21097.124.26.32/2797.124.26.33 to 97.124.26.6297.124.26.6330
21197.124.26.64/2797.124.26.65 to 97.124.26.9497.124.26.9530
21297.124.26.96/2797.124.26.97 to 97.124.26.12697.124.26.12730
21397.124.26.128/2797.124.26.129 to 97.124.26.15897.124.26.15930
21497.124.26.160/2797.124.26.161 to 97.124.26.19097.124.26.19130
21597.124.26.192/2797.124.26.193 to 97.124.26.22297.124.26.22330
21697.124.26.224/2797.124.26.225 to 97.124.26.25497.124.26.25530
21797.124.27.0/2797.124.27.1 to 97.124.27.3097.124.27.3130
21897.124.27.32/2797.124.27.33 to 97.124.27.6297.124.27.6330
21997.124.27.64/2797.124.27.65 to 97.124.27.9497.124.27.9530
22097.124.27.96/2797.124.27.97 to 97.124.27.12697.124.27.12730
22197.124.27.128/2797.124.27.129 to 97.124.27.15897.124.27.15930
22297.124.27.160/2797.124.27.161 to 97.124.27.19097.124.27.19130
22397.124.27.192/2797.124.27.193 to 97.124.27.22297.124.27.22330
22497.124.27.224/2797.124.27.225 to 97.124.27.25497.124.27.25530
22597.124.28.0/2797.124.28.1 to 97.124.28.3097.124.28.3130
22697.124.28.32/2797.124.28.33 to 97.124.28.6297.124.28.6330
22797.124.28.64/2797.124.28.65 to 97.124.28.9497.124.28.9530
22897.124.28.96/2797.124.28.97 to 97.124.28.12697.124.28.12730
22997.124.28.128/2797.124.28.129 to 97.124.28.15897.124.28.15930
23097.124.28.160/2797.124.28.161 to 97.124.28.19097.124.28.19130
23197.124.28.192/2797.124.28.193 to 97.124.28.22297.124.28.22330
23297.124.28.224/2797.124.28.225 to 97.124.28.25497.124.28.25530
23397.124.29.0/2797.124.29.1 to 97.124.29.3097.124.29.3130
23497.124.29.32/2797.124.29.33 to 97.124.29.6297.124.29.6330
23597.124.29.64/2797.124.29.65 to 97.124.29.9497.124.29.9530
23697.124.29.96/2797.124.29.97 to 97.124.29.12697.124.29.12730
23797.124.29.128/2797.124.29.129 to 97.124.29.15897.124.29.15930
23897.124.29.160/2797.124.29.161 to 97.124.29.19097.124.29.19130
23997.124.29.192/2797.124.29.193 to 97.124.29.22297.124.29.22330
24097.124.29.224/2797.124.29.225 to 97.124.29.25497.124.29.25530
24197.124.30.0/2797.124.30.1 to 97.124.30.3097.124.30.3130
24297.124.30.32/2797.124.30.33 to 97.124.30.6297.124.30.6330
24397.124.30.64/2797.124.30.65 to 97.124.30.9497.124.30.9530
24497.124.30.96/2797.124.30.97 to 97.124.30.12697.124.30.12730
24597.124.30.128/2797.124.30.129 to 97.124.30.15897.124.30.15930
24697.124.30.160/2797.124.30.161 to 97.124.30.19097.124.30.19130
24797.124.30.192/2797.124.30.193 to 97.124.30.22297.124.30.22330
24897.124.30.224/2797.124.30.225 to 97.124.30.25497.124.30.25530
24997.124.31.0/2797.124.31.1 to 97.124.31.3097.124.31.3130
25097.124.31.32/2797.124.31.33 to 97.124.31.6297.124.31.6330
25197.124.31.64/2797.124.31.65 to 97.124.31.9497.124.31.9530
25297.124.31.96/2797.124.31.97 to 97.124.31.12697.124.31.12730
25397.124.31.128/2797.124.31.129 to 97.124.31.15897.124.31.15930
25497.124.31.160/2797.124.31.161 to 97.124.31.19097.124.31.19130
25597.124.31.192/2797.124.31.193 to 97.124.31.22297.124.31.22330
25697.124.31.224/2797.124.31.225 to 97.124.31.25497.124.31.25530

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.