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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.

Network76.0.192.0/18
Usable hosts16,382
Subnet mask255.255.192.0
Addresses16,384
Network address
76.0.192.0
Broadcast address
76.0.255.255
First usable
76.0.192.1
Last usable
76.0.255.254
Usable hosts
16,382 (16,384 less the network and broadcast addresses)
Subnet mask
255.255.192.0
Wildcard mask
0.0.63.255 (Cisco ACLs, OSPF)
Prefix length
/18
Type
Public public
Old class
A (default /8)
As numbers
Hex 4C00C000 · Integer 1275117568 to 1275133951
Reverse DNS zones
192.0.76.in-addr.arpa
193.0.76.in-addr.arpa
194.0.76.in-addr.arpa
195.0.76.in-addr.arpa
196.0.76.in-addr.arpa
197.0.76.in-addr.arpa
198.0.76.in-addr.arpa
199.0.76.in-addr.arpa
200.0.76.in-addr.arpa
201.0.76.in-addr.arpa
202.0.76.in-addr.arpa
203.0.76.in-addr.arpa
204.0.76.in-addr.arpa
205.0.76.in-addr.arpa
206.0.76.in-addr.arpa
207.0.76.in-addr.arpa
and 48 more
/18 is not on a 8-bit boundary, so it takes 64 /24 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address01001100.00000000.11000000.0000000076.0.192.0
Subnet mask11111111.11111111.11000000.00000000255.255.192.0
Network01001100.00000000.11000000.0000000076.0.192.0
Broadcast01001100.00000000.11111111.1111111176.0.255.255
Split into smaller subnets/27
/19 (2)/20 (4)/21 (8)/22 (16)/23 (32)/24 (64)/25 (128)/26 (256)/27 (512)/28 (1,024)/29 (2,048)/30 (4,096)

76.0.192.0/18 makes 512 subnets of /27; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
176.0.192.0/2776.0.192.1 to 76.0.192.3076.0.192.3130
276.0.192.32/2776.0.192.33 to 76.0.192.6276.0.192.6330
376.0.192.64/2776.0.192.65 to 76.0.192.9476.0.192.9530
476.0.192.96/2776.0.192.97 to 76.0.192.12676.0.192.12730
576.0.192.128/2776.0.192.129 to 76.0.192.15876.0.192.15930
676.0.192.160/2776.0.192.161 to 76.0.192.19076.0.192.19130
776.0.192.192/2776.0.192.193 to 76.0.192.22276.0.192.22330
876.0.192.224/2776.0.192.225 to 76.0.192.25476.0.192.25530
976.0.193.0/2776.0.193.1 to 76.0.193.3076.0.193.3130
1076.0.193.32/2776.0.193.33 to 76.0.193.6276.0.193.6330
1176.0.193.64/2776.0.193.65 to 76.0.193.9476.0.193.9530
1276.0.193.96/2776.0.193.97 to 76.0.193.12676.0.193.12730
1376.0.193.128/2776.0.193.129 to 76.0.193.15876.0.193.15930
1476.0.193.160/2776.0.193.161 to 76.0.193.19076.0.193.19130
1576.0.193.192/2776.0.193.193 to 76.0.193.22276.0.193.22330
1676.0.193.224/2776.0.193.225 to 76.0.193.25476.0.193.25530
1776.0.194.0/2776.0.194.1 to 76.0.194.3076.0.194.3130
1876.0.194.32/2776.0.194.33 to 76.0.194.6276.0.194.6330
1976.0.194.64/2776.0.194.65 to 76.0.194.9476.0.194.9530
2076.0.194.96/2776.0.194.97 to 76.0.194.12676.0.194.12730
2176.0.194.128/2776.0.194.129 to 76.0.194.15876.0.194.15930
2276.0.194.160/2776.0.194.161 to 76.0.194.19076.0.194.19130
2376.0.194.192/2776.0.194.193 to 76.0.194.22276.0.194.22330
2476.0.194.224/2776.0.194.225 to 76.0.194.25476.0.194.25530
2576.0.195.0/2776.0.195.1 to 76.0.195.3076.0.195.3130
2676.0.195.32/2776.0.195.33 to 76.0.195.6276.0.195.6330
2776.0.195.64/2776.0.195.65 to 76.0.195.9476.0.195.9530
2876.0.195.96/2776.0.195.97 to 76.0.195.12676.0.195.12730
2976.0.195.128/2776.0.195.129 to 76.0.195.15876.0.195.15930
3076.0.195.160/2776.0.195.161 to 76.0.195.19076.0.195.19130
3176.0.195.192/2776.0.195.193 to 76.0.195.22276.0.195.22330
3276.0.195.224/2776.0.195.225 to 76.0.195.25476.0.195.25530
3376.0.196.0/2776.0.196.1 to 76.0.196.3076.0.196.3130
3476.0.196.32/2776.0.196.33 to 76.0.196.6276.0.196.6330
3576.0.196.64/2776.0.196.65 to 76.0.196.9476.0.196.9530
3676.0.196.96/2776.0.196.97 to 76.0.196.12676.0.196.12730
3776.0.196.128/2776.0.196.129 to 76.0.196.15876.0.196.15930
3876.0.196.160/2776.0.196.161 to 76.0.196.19076.0.196.19130
3976.0.196.192/2776.0.196.193 to 76.0.196.22276.0.196.22330
4076.0.196.224/2776.0.196.225 to 76.0.196.25476.0.196.25530
4176.0.197.0/2776.0.197.1 to 76.0.197.3076.0.197.3130
4276.0.197.32/2776.0.197.33 to 76.0.197.6276.0.197.6330
4376.0.197.64/2776.0.197.65 to 76.0.197.9476.0.197.9530
4476.0.197.96/2776.0.197.97 to 76.0.197.12676.0.197.12730
4576.0.197.128/2776.0.197.129 to 76.0.197.15876.0.197.15930
4676.0.197.160/2776.0.197.161 to 76.0.197.19076.0.197.19130
4776.0.197.192/2776.0.197.193 to 76.0.197.22276.0.197.22330
4876.0.197.224/2776.0.197.225 to 76.0.197.25476.0.197.25530
4976.0.198.0/2776.0.198.1 to 76.0.198.3076.0.198.3130
5076.0.198.32/2776.0.198.33 to 76.0.198.6276.0.198.6330
5176.0.198.64/2776.0.198.65 to 76.0.198.9476.0.198.9530
5276.0.198.96/2776.0.198.97 to 76.0.198.12676.0.198.12730
5376.0.198.128/2776.0.198.129 to 76.0.198.15876.0.198.15930
5476.0.198.160/2776.0.198.161 to 76.0.198.19076.0.198.19130
5576.0.198.192/2776.0.198.193 to 76.0.198.22276.0.198.22330
5676.0.198.224/2776.0.198.225 to 76.0.198.25476.0.198.25530
5776.0.199.0/2776.0.199.1 to 76.0.199.3076.0.199.3130
5876.0.199.32/2776.0.199.33 to 76.0.199.6276.0.199.6330
5976.0.199.64/2776.0.199.65 to 76.0.199.9476.0.199.9530
6076.0.199.96/2776.0.199.97 to 76.0.199.12676.0.199.12730
6176.0.199.128/2776.0.199.129 to 76.0.199.15876.0.199.15930
6276.0.199.160/2776.0.199.161 to 76.0.199.19076.0.199.19130
6376.0.199.192/2776.0.199.193 to 76.0.199.22276.0.199.22330
6476.0.199.224/2776.0.199.225 to 76.0.199.25476.0.199.25530
6576.0.200.0/2776.0.200.1 to 76.0.200.3076.0.200.3130
6676.0.200.32/2776.0.200.33 to 76.0.200.6276.0.200.6330
6776.0.200.64/2776.0.200.65 to 76.0.200.9476.0.200.9530
6876.0.200.96/2776.0.200.97 to 76.0.200.12676.0.200.12730
6976.0.200.128/2776.0.200.129 to 76.0.200.15876.0.200.15930
7076.0.200.160/2776.0.200.161 to 76.0.200.19076.0.200.19130
7176.0.200.192/2776.0.200.193 to 76.0.200.22276.0.200.22330
7276.0.200.224/2776.0.200.225 to 76.0.200.25476.0.200.25530
7376.0.201.0/2776.0.201.1 to 76.0.201.3076.0.201.3130
7476.0.201.32/2776.0.201.33 to 76.0.201.6276.0.201.6330
7576.0.201.64/2776.0.201.65 to 76.0.201.9476.0.201.9530
7676.0.201.96/2776.0.201.97 to 76.0.201.12676.0.201.12730
7776.0.201.128/2776.0.201.129 to 76.0.201.15876.0.201.15930
7876.0.201.160/2776.0.201.161 to 76.0.201.19076.0.201.19130
7976.0.201.192/2776.0.201.193 to 76.0.201.22276.0.201.22330
8076.0.201.224/2776.0.201.225 to 76.0.201.25476.0.201.25530
8176.0.202.0/2776.0.202.1 to 76.0.202.3076.0.202.3130
8276.0.202.32/2776.0.202.33 to 76.0.202.6276.0.202.6330
8376.0.202.64/2776.0.202.65 to 76.0.202.9476.0.202.9530
8476.0.202.96/2776.0.202.97 to 76.0.202.12676.0.202.12730
8576.0.202.128/2776.0.202.129 to 76.0.202.15876.0.202.15930
8676.0.202.160/2776.0.202.161 to 76.0.202.19076.0.202.19130
8776.0.202.192/2776.0.202.193 to 76.0.202.22276.0.202.22330
8876.0.202.224/2776.0.202.225 to 76.0.202.25476.0.202.25530
8976.0.203.0/2776.0.203.1 to 76.0.203.3076.0.203.3130
9076.0.203.32/2776.0.203.33 to 76.0.203.6276.0.203.6330
9176.0.203.64/2776.0.203.65 to 76.0.203.9476.0.203.9530
9276.0.203.96/2776.0.203.97 to 76.0.203.12676.0.203.12730
9376.0.203.128/2776.0.203.129 to 76.0.203.15876.0.203.15930
9476.0.203.160/2776.0.203.161 to 76.0.203.19076.0.203.19130
9576.0.203.192/2776.0.203.193 to 76.0.203.22276.0.203.22330
9676.0.203.224/2776.0.203.225 to 76.0.203.25476.0.203.25530
9776.0.204.0/2776.0.204.1 to 76.0.204.3076.0.204.3130
9876.0.204.32/2776.0.204.33 to 76.0.204.6276.0.204.6330
9976.0.204.64/2776.0.204.65 to 76.0.204.9476.0.204.9530
10076.0.204.96/2776.0.204.97 to 76.0.204.12676.0.204.12730
10176.0.204.128/2776.0.204.129 to 76.0.204.15876.0.204.15930
10276.0.204.160/2776.0.204.161 to 76.0.204.19076.0.204.19130
10376.0.204.192/2776.0.204.193 to 76.0.204.22276.0.204.22330
10476.0.204.224/2776.0.204.225 to 76.0.204.25476.0.204.25530
10576.0.205.0/2776.0.205.1 to 76.0.205.3076.0.205.3130
10676.0.205.32/2776.0.205.33 to 76.0.205.6276.0.205.6330
10776.0.205.64/2776.0.205.65 to 76.0.205.9476.0.205.9530
10876.0.205.96/2776.0.205.97 to 76.0.205.12676.0.205.12730
10976.0.205.128/2776.0.205.129 to 76.0.205.15876.0.205.15930
11076.0.205.160/2776.0.205.161 to 76.0.205.19076.0.205.19130
11176.0.205.192/2776.0.205.193 to 76.0.205.22276.0.205.22330
11276.0.205.224/2776.0.205.225 to 76.0.205.25476.0.205.25530
11376.0.206.0/2776.0.206.1 to 76.0.206.3076.0.206.3130
11476.0.206.32/2776.0.206.33 to 76.0.206.6276.0.206.6330
11576.0.206.64/2776.0.206.65 to 76.0.206.9476.0.206.9530
11676.0.206.96/2776.0.206.97 to 76.0.206.12676.0.206.12730
11776.0.206.128/2776.0.206.129 to 76.0.206.15876.0.206.15930
11876.0.206.160/2776.0.206.161 to 76.0.206.19076.0.206.19130
11976.0.206.192/2776.0.206.193 to 76.0.206.22276.0.206.22330
12076.0.206.224/2776.0.206.225 to 76.0.206.25476.0.206.25530
12176.0.207.0/2776.0.207.1 to 76.0.207.3076.0.207.3130
12276.0.207.32/2776.0.207.33 to 76.0.207.6276.0.207.6330
12376.0.207.64/2776.0.207.65 to 76.0.207.9476.0.207.9530
12476.0.207.96/2776.0.207.97 to 76.0.207.12676.0.207.12730
12576.0.207.128/2776.0.207.129 to 76.0.207.15876.0.207.15930
12676.0.207.160/2776.0.207.161 to 76.0.207.19076.0.207.19130
12776.0.207.192/2776.0.207.193 to 76.0.207.22276.0.207.22330
12876.0.207.224/2776.0.207.225 to 76.0.207.25476.0.207.25530
12976.0.208.0/2776.0.208.1 to 76.0.208.3076.0.208.3130
13076.0.208.32/2776.0.208.33 to 76.0.208.6276.0.208.6330
13176.0.208.64/2776.0.208.65 to 76.0.208.9476.0.208.9530
13276.0.208.96/2776.0.208.97 to 76.0.208.12676.0.208.12730
13376.0.208.128/2776.0.208.129 to 76.0.208.15876.0.208.15930
13476.0.208.160/2776.0.208.161 to 76.0.208.19076.0.208.19130
13576.0.208.192/2776.0.208.193 to 76.0.208.22276.0.208.22330
13676.0.208.224/2776.0.208.225 to 76.0.208.25476.0.208.25530
13776.0.209.0/2776.0.209.1 to 76.0.209.3076.0.209.3130
13876.0.209.32/2776.0.209.33 to 76.0.209.6276.0.209.6330
13976.0.209.64/2776.0.209.65 to 76.0.209.9476.0.209.9530
14076.0.209.96/2776.0.209.97 to 76.0.209.12676.0.209.12730
14176.0.209.128/2776.0.209.129 to 76.0.209.15876.0.209.15930
14276.0.209.160/2776.0.209.161 to 76.0.209.19076.0.209.19130
14376.0.209.192/2776.0.209.193 to 76.0.209.22276.0.209.22330
14476.0.209.224/2776.0.209.225 to 76.0.209.25476.0.209.25530
14576.0.210.0/2776.0.210.1 to 76.0.210.3076.0.210.3130
14676.0.210.32/2776.0.210.33 to 76.0.210.6276.0.210.6330
14776.0.210.64/2776.0.210.65 to 76.0.210.9476.0.210.9530
14876.0.210.96/2776.0.210.97 to 76.0.210.12676.0.210.12730
14976.0.210.128/2776.0.210.129 to 76.0.210.15876.0.210.15930
15076.0.210.160/2776.0.210.161 to 76.0.210.19076.0.210.19130
15176.0.210.192/2776.0.210.193 to 76.0.210.22276.0.210.22330
15276.0.210.224/2776.0.210.225 to 76.0.210.25476.0.210.25530
15376.0.211.0/2776.0.211.1 to 76.0.211.3076.0.211.3130
15476.0.211.32/2776.0.211.33 to 76.0.211.6276.0.211.6330
15576.0.211.64/2776.0.211.65 to 76.0.211.9476.0.211.9530
15676.0.211.96/2776.0.211.97 to 76.0.211.12676.0.211.12730
15776.0.211.128/2776.0.211.129 to 76.0.211.15876.0.211.15930
15876.0.211.160/2776.0.211.161 to 76.0.211.19076.0.211.19130
15976.0.211.192/2776.0.211.193 to 76.0.211.22276.0.211.22330
16076.0.211.224/2776.0.211.225 to 76.0.211.25476.0.211.25530
16176.0.212.0/2776.0.212.1 to 76.0.212.3076.0.212.3130
16276.0.212.32/2776.0.212.33 to 76.0.212.6276.0.212.6330
16376.0.212.64/2776.0.212.65 to 76.0.212.9476.0.212.9530
16476.0.212.96/2776.0.212.97 to 76.0.212.12676.0.212.12730
16576.0.212.128/2776.0.212.129 to 76.0.212.15876.0.212.15930
16676.0.212.160/2776.0.212.161 to 76.0.212.19076.0.212.19130
16776.0.212.192/2776.0.212.193 to 76.0.212.22276.0.212.22330
16876.0.212.224/2776.0.212.225 to 76.0.212.25476.0.212.25530
16976.0.213.0/2776.0.213.1 to 76.0.213.3076.0.213.3130
17076.0.213.32/2776.0.213.33 to 76.0.213.6276.0.213.6330
17176.0.213.64/2776.0.213.65 to 76.0.213.9476.0.213.9530
17276.0.213.96/2776.0.213.97 to 76.0.213.12676.0.213.12730
17376.0.213.128/2776.0.213.129 to 76.0.213.15876.0.213.15930
17476.0.213.160/2776.0.213.161 to 76.0.213.19076.0.213.19130
17576.0.213.192/2776.0.213.193 to 76.0.213.22276.0.213.22330
17676.0.213.224/2776.0.213.225 to 76.0.213.25476.0.213.25530
17776.0.214.0/2776.0.214.1 to 76.0.214.3076.0.214.3130
17876.0.214.32/2776.0.214.33 to 76.0.214.6276.0.214.6330
17976.0.214.64/2776.0.214.65 to 76.0.214.9476.0.214.9530
18076.0.214.96/2776.0.214.97 to 76.0.214.12676.0.214.12730
18176.0.214.128/2776.0.214.129 to 76.0.214.15876.0.214.15930
18276.0.214.160/2776.0.214.161 to 76.0.214.19076.0.214.19130
18376.0.214.192/2776.0.214.193 to 76.0.214.22276.0.214.22330
18476.0.214.224/2776.0.214.225 to 76.0.214.25476.0.214.25530
18576.0.215.0/2776.0.215.1 to 76.0.215.3076.0.215.3130
18676.0.215.32/2776.0.215.33 to 76.0.215.6276.0.215.6330
18776.0.215.64/2776.0.215.65 to 76.0.215.9476.0.215.9530
18876.0.215.96/2776.0.215.97 to 76.0.215.12676.0.215.12730
18976.0.215.128/2776.0.215.129 to 76.0.215.15876.0.215.15930
19076.0.215.160/2776.0.215.161 to 76.0.215.19076.0.215.19130
19176.0.215.192/2776.0.215.193 to 76.0.215.22276.0.215.22330
19276.0.215.224/2776.0.215.225 to 76.0.215.25476.0.215.25530
19376.0.216.0/2776.0.216.1 to 76.0.216.3076.0.216.3130
19476.0.216.32/2776.0.216.33 to 76.0.216.6276.0.216.6330
19576.0.216.64/2776.0.216.65 to 76.0.216.9476.0.216.9530
19676.0.216.96/2776.0.216.97 to 76.0.216.12676.0.216.12730
19776.0.216.128/2776.0.216.129 to 76.0.216.15876.0.216.15930
19876.0.216.160/2776.0.216.161 to 76.0.216.19076.0.216.19130
19976.0.216.192/2776.0.216.193 to 76.0.216.22276.0.216.22330
20076.0.216.224/2776.0.216.225 to 76.0.216.25476.0.216.25530
20176.0.217.0/2776.0.217.1 to 76.0.217.3076.0.217.3130
20276.0.217.32/2776.0.217.33 to 76.0.217.6276.0.217.6330
20376.0.217.64/2776.0.217.65 to 76.0.217.9476.0.217.9530
20476.0.217.96/2776.0.217.97 to 76.0.217.12676.0.217.12730
20576.0.217.128/2776.0.217.129 to 76.0.217.15876.0.217.15930
20676.0.217.160/2776.0.217.161 to 76.0.217.19076.0.217.19130
20776.0.217.192/2776.0.217.193 to 76.0.217.22276.0.217.22330
20876.0.217.224/2776.0.217.225 to 76.0.217.25476.0.217.25530
20976.0.218.0/2776.0.218.1 to 76.0.218.3076.0.218.3130
21076.0.218.32/2776.0.218.33 to 76.0.218.6276.0.218.6330
21176.0.218.64/2776.0.218.65 to 76.0.218.9476.0.218.9530
21276.0.218.96/2776.0.218.97 to 76.0.218.12676.0.218.12730
21376.0.218.128/2776.0.218.129 to 76.0.218.15876.0.218.15930
21476.0.218.160/2776.0.218.161 to 76.0.218.19076.0.218.19130
21576.0.218.192/2776.0.218.193 to 76.0.218.22276.0.218.22330
21676.0.218.224/2776.0.218.225 to 76.0.218.25476.0.218.25530
21776.0.219.0/2776.0.219.1 to 76.0.219.3076.0.219.3130
21876.0.219.32/2776.0.219.33 to 76.0.219.6276.0.219.6330
21976.0.219.64/2776.0.219.65 to 76.0.219.9476.0.219.9530
22076.0.219.96/2776.0.219.97 to 76.0.219.12676.0.219.12730
22176.0.219.128/2776.0.219.129 to 76.0.219.15876.0.219.15930
22276.0.219.160/2776.0.219.161 to 76.0.219.19076.0.219.19130
22376.0.219.192/2776.0.219.193 to 76.0.219.22276.0.219.22330
22476.0.219.224/2776.0.219.225 to 76.0.219.25476.0.219.25530
22576.0.220.0/2776.0.220.1 to 76.0.220.3076.0.220.3130
22676.0.220.32/2776.0.220.33 to 76.0.220.6276.0.220.6330
22776.0.220.64/2776.0.220.65 to 76.0.220.9476.0.220.9530
22876.0.220.96/2776.0.220.97 to 76.0.220.12676.0.220.12730
22976.0.220.128/2776.0.220.129 to 76.0.220.15876.0.220.15930
23076.0.220.160/2776.0.220.161 to 76.0.220.19076.0.220.19130
23176.0.220.192/2776.0.220.193 to 76.0.220.22276.0.220.22330
23276.0.220.224/2776.0.220.225 to 76.0.220.25476.0.220.25530
23376.0.221.0/2776.0.221.1 to 76.0.221.3076.0.221.3130
23476.0.221.32/2776.0.221.33 to 76.0.221.6276.0.221.6330
23576.0.221.64/2776.0.221.65 to 76.0.221.9476.0.221.9530
23676.0.221.96/2776.0.221.97 to 76.0.221.12676.0.221.12730
23776.0.221.128/2776.0.221.129 to 76.0.221.15876.0.221.15930
23876.0.221.160/2776.0.221.161 to 76.0.221.19076.0.221.19130
23976.0.221.192/2776.0.221.193 to 76.0.221.22276.0.221.22330
24076.0.221.224/2776.0.221.225 to 76.0.221.25476.0.221.25530
24176.0.222.0/2776.0.222.1 to 76.0.222.3076.0.222.3130
24276.0.222.32/2776.0.222.33 to 76.0.222.6276.0.222.6330
24376.0.222.64/2776.0.222.65 to 76.0.222.9476.0.222.9530
24476.0.222.96/2776.0.222.97 to 76.0.222.12676.0.222.12730
24576.0.222.128/2776.0.222.129 to 76.0.222.15876.0.222.15930
24676.0.222.160/2776.0.222.161 to 76.0.222.19076.0.222.19130
24776.0.222.192/2776.0.222.193 to 76.0.222.22276.0.222.22330
24876.0.222.224/2776.0.222.225 to 76.0.222.25476.0.222.25530
24976.0.223.0/2776.0.223.1 to 76.0.223.3076.0.223.3130
25076.0.223.32/2776.0.223.33 to 76.0.223.6276.0.223.6330
25176.0.223.64/2776.0.223.65 to 76.0.223.9476.0.223.9530
25276.0.223.96/2776.0.223.97 to 76.0.223.12676.0.223.12730
25376.0.223.128/2776.0.223.129 to 76.0.223.15876.0.223.15930
25476.0.223.160/2776.0.223.161 to 76.0.223.19076.0.223.19130
25576.0.223.192/2776.0.223.193 to 76.0.223.22276.0.223.22330
25676.0.223.224/2776.0.223.225 to 76.0.223.25476.0.223.25530

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.