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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.

Network57.26.0.0/18
Usable hosts16,382
Subnet mask255.255.192.0
Addresses16,384
Network address
57.26.0.0
Broadcast address
57.26.63.255
First usable
57.26.0.1
Last usable
57.26.63.254
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 391A0000 · Integer 958005248 to 958021631
Reverse DNS zones
0.26.57.in-addr.arpa
1.26.57.in-addr.arpa
2.26.57.in-addr.arpa
3.26.57.in-addr.arpa
4.26.57.in-addr.arpa
5.26.57.in-addr.arpa
6.26.57.in-addr.arpa
7.26.57.in-addr.arpa
8.26.57.in-addr.arpa
9.26.57.in-addr.arpa
10.26.57.in-addr.arpa
11.26.57.in-addr.arpa
12.26.57.in-addr.arpa
13.26.57.in-addr.arpa
14.26.57.in-addr.arpa
15.26.57.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
Address00111001.00011010.00000000.0000000057.26.0.0
Subnet mask11111111.11111111.11000000.00000000255.255.192.0
Network00111001.00011010.00000000.0000000057.26.0.0
Broadcast00111001.00011010.00111111.1111111157.26.63.255
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)

57.26.0.0/18 makes 512 subnets of /27; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
157.26.0.0/2757.26.0.1 to 57.26.0.3057.26.0.3130
257.26.0.32/2757.26.0.33 to 57.26.0.6257.26.0.6330
357.26.0.64/2757.26.0.65 to 57.26.0.9457.26.0.9530
457.26.0.96/2757.26.0.97 to 57.26.0.12657.26.0.12730
557.26.0.128/2757.26.0.129 to 57.26.0.15857.26.0.15930
657.26.0.160/2757.26.0.161 to 57.26.0.19057.26.0.19130
757.26.0.192/2757.26.0.193 to 57.26.0.22257.26.0.22330
857.26.0.224/2757.26.0.225 to 57.26.0.25457.26.0.25530
957.26.1.0/2757.26.1.1 to 57.26.1.3057.26.1.3130
1057.26.1.32/2757.26.1.33 to 57.26.1.6257.26.1.6330
1157.26.1.64/2757.26.1.65 to 57.26.1.9457.26.1.9530
1257.26.1.96/2757.26.1.97 to 57.26.1.12657.26.1.12730
1357.26.1.128/2757.26.1.129 to 57.26.1.15857.26.1.15930
1457.26.1.160/2757.26.1.161 to 57.26.1.19057.26.1.19130
1557.26.1.192/2757.26.1.193 to 57.26.1.22257.26.1.22330
1657.26.1.224/2757.26.1.225 to 57.26.1.25457.26.1.25530
1757.26.2.0/2757.26.2.1 to 57.26.2.3057.26.2.3130
1857.26.2.32/2757.26.2.33 to 57.26.2.6257.26.2.6330
1957.26.2.64/2757.26.2.65 to 57.26.2.9457.26.2.9530
2057.26.2.96/2757.26.2.97 to 57.26.2.12657.26.2.12730
2157.26.2.128/2757.26.2.129 to 57.26.2.15857.26.2.15930
2257.26.2.160/2757.26.2.161 to 57.26.2.19057.26.2.19130
2357.26.2.192/2757.26.2.193 to 57.26.2.22257.26.2.22330
2457.26.2.224/2757.26.2.225 to 57.26.2.25457.26.2.25530
2557.26.3.0/2757.26.3.1 to 57.26.3.3057.26.3.3130
2657.26.3.32/2757.26.3.33 to 57.26.3.6257.26.3.6330
2757.26.3.64/2757.26.3.65 to 57.26.3.9457.26.3.9530
2857.26.3.96/2757.26.3.97 to 57.26.3.12657.26.3.12730
2957.26.3.128/2757.26.3.129 to 57.26.3.15857.26.3.15930
3057.26.3.160/2757.26.3.161 to 57.26.3.19057.26.3.19130
3157.26.3.192/2757.26.3.193 to 57.26.3.22257.26.3.22330
3257.26.3.224/2757.26.3.225 to 57.26.3.25457.26.3.25530
3357.26.4.0/2757.26.4.1 to 57.26.4.3057.26.4.3130
3457.26.4.32/2757.26.4.33 to 57.26.4.6257.26.4.6330
3557.26.4.64/2757.26.4.65 to 57.26.4.9457.26.4.9530
3657.26.4.96/2757.26.4.97 to 57.26.4.12657.26.4.12730
3757.26.4.128/2757.26.4.129 to 57.26.4.15857.26.4.15930
3857.26.4.160/2757.26.4.161 to 57.26.4.19057.26.4.19130
3957.26.4.192/2757.26.4.193 to 57.26.4.22257.26.4.22330
4057.26.4.224/2757.26.4.225 to 57.26.4.25457.26.4.25530
4157.26.5.0/2757.26.5.1 to 57.26.5.3057.26.5.3130
4257.26.5.32/2757.26.5.33 to 57.26.5.6257.26.5.6330
4357.26.5.64/2757.26.5.65 to 57.26.5.9457.26.5.9530
4457.26.5.96/2757.26.5.97 to 57.26.5.12657.26.5.12730
4557.26.5.128/2757.26.5.129 to 57.26.5.15857.26.5.15930
4657.26.5.160/2757.26.5.161 to 57.26.5.19057.26.5.19130
4757.26.5.192/2757.26.5.193 to 57.26.5.22257.26.5.22330
4857.26.5.224/2757.26.5.225 to 57.26.5.25457.26.5.25530
4957.26.6.0/2757.26.6.1 to 57.26.6.3057.26.6.3130
5057.26.6.32/2757.26.6.33 to 57.26.6.6257.26.6.6330
5157.26.6.64/2757.26.6.65 to 57.26.6.9457.26.6.9530
5257.26.6.96/2757.26.6.97 to 57.26.6.12657.26.6.12730
5357.26.6.128/2757.26.6.129 to 57.26.6.15857.26.6.15930
5457.26.6.160/2757.26.6.161 to 57.26.6.19057.26.6.19130
5557.26.6.192/2757.26.6.193 to 57.26.6.22257.26.6.22330
5657.26.6.224/2757.26.6.225 to 57.26.6.25457.26.6.25530
5757.26.7.0/2757.26.7.1 to 57.26.7.3057.26.7.3130
5857.26.7.32/2757.26.7.33 to 57.26.7.6257.26.7.6330
5957.26.7.64/2757.26.7.65 to 57.26.7.9457.26.7.9530
6057.26.7.96/2757.26.7.97 to 57.26.7.12657.26.7.12730
6157.26.7.128/2757.26.7.129 to 57.26.7.15857.26.7.15930
6257.26.7.160/2757.26.7.161 to 57.26.7.19057.26.7.19130
6357.26.7.192/2757.26.7.193 to 57.26.7.22257.26.7.22330
6457.26.7.224/2757.26.7.225 to 57.26.7.25457.26.7.25530
6557.26.8.0/2757.26.8.1 to 57.26.8.3057.26.8.3130
6657.26.8.32/2757.26.8.33 to 57.26.8.6257.26.8.6330
6757.26.8.64/2757.26.8.65 to 57.26.8.9457.26.8.9530
6857.26.8.96/2757.26.8.97 to 57.26.8.12657.26.8.12730
6957.26.8.128/2757.26.8.129 to 57.26.8.15857.26.8.15930
7057.26.8.160/2757.26.8.161 to 57.26.8.19057.26.8.19130
7157.26.8.192/2757.26.8.193 to 57.26.8.22257.26.8.22330
7257.26.8.224/2757.26.8.225 to 57.26.8.25457.26.8.25530
7357.26.9.0/2757.26.9.1 to 57.26.9.3057.26.9.3130
7457.26.9.32/2757.26.9.33 to 57.26.9.6257.26.9.6330
7557.26.9.64/2757.26.9.65 to 57.26.9.9457.26.9.9530
7657.26.9.96/2757.26.9.97 to 57.26.9.12657.26.9.12730
7757.26.9.128/2757.26.9.129 to 57.26.9.15857.26.9.15930
7857.26.9.160/2757.26.9.161 to 57.26.9.19057.26.9.19130
7957.26.9.192/2757.26.9.193 to 57.26.9.22257.26.9.22330
8057.26.9.224/2757.26.9.225 to 57.26.9.25457.26.9.25530
8157.26.10.0/2757.26.10.1 to 57.26.10.3057.26.10.3130
8257.26.10.32/2757.26.10.33 to 57.26.10.6257.26.10.6330
8357.26.10.64/2757.26.10.65 to 57.26.10.9457.26.10.9530
8457.26.10.96/2757.26.10.97 to 57.26.10.12657.26.10.12730
8557.26.10.128/2757.26.10.129 to 57.26.10.15857.26.10.15930
8657.26.10.160/2757.26.10.161 to 57.26.10.19057.26.10.19130
8757.26.10.192/2757.26.10.193 to 57.26.10.22257.26.10.22330
8857.26.10.224/2757.26.10.225 to 57.26.10.25457.26.10.25530
8957.26.11.0/2757.26.11.1 to 57.26.11.3057.26.11.3130
9057.26.11.32/2757.26.11.33 to 57.26.11.6257.26.11.6330
9157.26.11.64/2757.26.11.65 to 57.26.11.9457.26.11.9530
9257.26.11.96/2757.26.11.97 to 57.26.11.12657.26.11.12730
9357.26.11.128/2757.26.11.129 to 57.26.11.15857.26.11.15930
9457.26.11.160/2757.26.11.161 to 57.26.11.19057.26.11.19130
9557.26.11.192/2757.26.11.193 to 57.26.11.22257.26.11.22330
9657.26.11.224/2757.26.11.225 to 57.26.11.25457.26.11.25530
9757.26.12.0/2757.26.12.1 to 57.26.12.3057.26.12.3130
9857.26.12.32/2757.26.12.33 to 57.26.12.6257.26.12.6330
9957.26.12.64/2757.26.12.65 to 57.26.12.9457.26.12.9530
10057.26.12.96/2757.26.12.97 to 57.26.12.12657.26.12.12730
10157.26.12.128/2757.26.12.129 to 57.26.12.15857.26.12.15930
10257.26.12.160/2757.26.12.161 to 57.26.12.19057.26.12.19130
10357.26.12.192/2757.26.12.193 to 57.26.12.22257.26.12.22330
10457.26.12.224/2757.26.12.225 to 57.26.12.25457.26.12.25530
10557.26.13.0/2757.26.13.1 to 57.26.13.3057.26.13.3130
10657.26.13.32/2757.26.13.33 to 57.26.13.6257.26.13.6330
10757.26.13.64/2757.26.13.65 to 57.26.13.9457.26.13.9530
10857.26.13.96/2757.26.13.97 to 57.26.13.12657.26.13.12730
10957.26.13.128/2757.26.13.129 to 57.26.13.15857.26.13.15930
11057.26.13.160/2757.26.13.161 to 57.26.13.19057.26.13.19130
11157.26.13.192/2757.26.13.193 to 57.26.13.22257.26.13.22330
11257.26.13.224/2757.26.13.225 to 57.26.13.25457.26.13.25530
11357.26.14.0/2757.26.14.1 to 57.26.14.3057.26.14.3130
11457.26.14.32/2757.26.14.33 to 57.26.14.6257.26.14.6330
11557.26.14.64/2757.26.14.65 to 57.26.14.9457.26.14.9530
11657.26.14.96/2757.26.14.97 to 57.26.14.12657.26.14.12730
11757.26.14.128/2757.26.14.129 to 57.26.14.15857.26.14.15930
11857.26.14.160/2757.26.14.161 to 57.26.14.19057.26.14.19130
11957.26.14.192/2757.26.14.193 to 57.26.14.22257.26.14.22330
12057.26.14.224/2757.26.14.225 to 57.26.14.25457.26.14.25530
12157.26.15.0/2757.26.15.1 to 57.26.15.3057.26.15.3130
12257.26.15.32/2757.26.15.33 to 57.26.15.6257.26.15.6330
12357.26.15.64/2757.26.15.65 to 57.26.15.9457.26.15.9530
12457.26.15.96/2757.26.15.97 to 57.26.15.12657.26.15.12730
12557.26.15.128/2757.26.15.129 to 57.26.15.15857.26.15.15930
12657.26.15.160/2757.26.15.161 to 57.26.15.19057.26.15.19130
12757.26.15.192/2757.26.15.193 to 57.26.15.22257.26.15.22330
12857.26.15.224/2757.26.15.225 to 57.26.15.25457.26.15.25530
12957.26.16.0/2757.26.16.1 to 57.26.16.3057.26.16.3130
13057.26.16.32/2757.26.16.33 to 57.26.16.6257.26.16.6330
13157.26.16.64/2757.26.16.65 to 57.26.16.9457.26.16.9530
13257.26.16.96/2757.26.16.97 to 57.26.16.12657.26.16.12730
13357.26.16.128/2757.26.16.129 to 57.26.16.15857.26.16.15930
13457.26.16.160/2757.26.16.161 to 57.26.16.19057.26.16.19130
13557.26.16.192/2757.26.16.193 to 57.26.16.22257.26.16.22330
13657.26.16.224/2757.26.16.225 to 57.26.16.25457.26.16.25530
13757.26.17.0/2757.26.17.1 to 57.26.17.3057.26.17.3130
13857.26.17.32/2757.26.17.33 to 57.26.17.6257.26.17.6330
13957.26.17.64/2757.26.17.65 to 57.26.17.9457.26.17.9530
14057.26.17.96/2757.26.17.97 to 57.26.17.12657.26.17.12730
14157.26.17.128/2757.26.17.129 to 57.26.17.15857.26.17.15930
14257.26.17.160/2757.26.17.161 to 57.26.17.19057.26.17.19130
14357.26.17.192/2757.26.17.193 to 57.26.17.22257.26.17.22330
14457.26.17.224/2757.26.17.225 to 57.26.17.25457.26.17.25530
14557.26.18.0/2757.26.18.1 to 57.26.18.3057.26.18.3130
14657.26.18.32/2757.26.18.33 to 57.26.18.6257.26.18.6330
14757.26.18.64/2757.26.18.65 to 57.26.18.9457.26.18.9530
14857.26.18.96/2757.26.18.97 to 57.26.18.12657.26.18.12730
14957.26.18.128/2757.26.18.129 to 57.26.18.15857.26.18.15930
15057.26.18.160/2757.26.18.161 to 57.26.18.19057.26.18.19130
15157.26.18.192/2757.26.18.193 to 57.26.18.22257.26.18.22330
15257.26.18.224/2757.26.18.225 to 57.26.18.25457.26.18.25530
15357.26.19.0/2757.26.19.1 to 57.26.19.3057.26.19.3130
15457.26.19.32/2757.26.19.33 to 57.26.19.6257.26.19.6330
15557.26.19.64/2757.26.19.65 to 57.26.19.9457.26.19.9530
15657.26.19.96/2757.26.19.97 to 57.26.19.12657.26.19.12730
15757.26.19.128/2757.26.19.129 to 57.26.19.15857.26.19.15930
15857.26.19.160/2757.26.19.161 to 57.26.19.19057.26.19.19130
15957.26.19.192/2757.26.19.193 to 57.26.19.22257.26.19.22330
16057.26.19.224/2757.26.19.225 to 57.26.19.25457.26.19.25530
16157.26.20.0/2757.26.20.1 to 57.26.20.3057.26.20.3130
16257.26.20.32/2757.26.20.33 to 57.26.20.6257.26.20.6330
16357.26.20.64/2757.26.20.65 to 57.26.20.9457.26.20.9530
16457.26.20.96/2757.26.20.97 to 57.26.20.12657.26.20.12730
16557.26.20.128/2757.26.20.129 to 57.26.20.15857.26.20.15930
16657.26.20.160/2757.26.20.161 to 57.26.20.19057.26.20.19130
16757.26.20.192/2757.26.20.193 to 57.26.20.22257.26.20.22330
16857.26.20.224/2757.26.20.225 to 57.26.20.25457.26.20.25530
16957.26.21.0/2757.26.21.1 to 57.26.21.3057.26.21.3130
17057.26.21.32/2757.26.21.33 to 57.26.21.6257.26.21.6330
17157.26.21.64/2757.26.21.65 to 57.26.21.9457.26.21.9530
17257.26.21.96/2757.26.21.97 to 57.26.21.12657.26.21.12730
17357.26.21.128/2757.26.21.129 to 57.26.21.15857.26.21.15930
17457.26.21.160/2757.26.21.161 to 57.26.21.19057.26.21.19130
17557.26.21.192/2757.26.21.193 to 57.26.21.22257.26.21.22330
17657.26.21.224/2757.26.21.225 to 57.26.21.25457.26.21.25530
17757.26.22.0/2757.26.22.1 to 57.26.22.3057.26.22.3130
17857.26.22.32/2757.26.22.33 to 57.26.22.6257.26.22.6330
17957.26.22.64/2757.26.22.65 to 57.26.22.9457.26.22.9530
18057.26.22.96/2757.26.22.97 to 57.26.22.12657.26.22.12730
18157.26.22.128/2757.26.22.129 to 57.26.22.15857.26.22.15930
18257.26.22.160/2757.26.22.161 to 57.26.22.19057.26.22.19130
18357.26.22.192/2757.26.22.193 to 57.26.22.22257.26.22.22330
18457.26.22.224/2757.26.22.225 to 57.26.22.25457.26.22.25530
18557.26.23.0/2757.26.23.1 to 57.26.23.3057.26.23.3130
18657.26.23.32/2757.26.23.33 to 57.26.23.6257.26.23.6330
18757.26.23.64/2757.26.23.65 to 57.26.23.9457.26.23.9530
18857.26.23.96/2757.26.23.97 to 57.26.23.12657.26.23.12730
18957.26.23.128/2757.26.23.129 to 57.26.23.15857.26.23.15930
19057.26.23.160/2757.26.23.161 to 57.26.23.19057.26.23.19130
19157.26.23.192/2757.26.23.193 to 57.26.23.22257.26.23.22330
19257.26.23.224/2757.26.23.225 to 57.26.23.25457.26.23.25530
19357.26.24.0/2757.26.24.1 to 57.26.24.3057.26.24.3130
19457.26.24.32/2757.26.24.33 to 57.26.24.6257.26.24.6330
19557.26.24.64/2757.26.24.65 to 57.26.24.9457.26.24.9530
19657.26.24.96/2757.26.24.97 to 57.26.24.12657.26.24.12730
19757.26.24.128/2757.26.24.129 to 57.26.24.15857.26.24.15930
19857.26.24.160/2757.26.24.161 to 57.26.24.19057.26.24.19130
19957.26.24.192/2757.26.24.193 to 57.26.24.22257.26.24.22330
20057.26.24.224/2757.26.24.225 to 57.26.24.25457.26.24.25530
20157.26.25.0/2757.26.25.1 to 57.26.25.3057.26.25.3130
20257.26.25.32/2757.26.25.33 to 57.26.25.6257.26.25.6330
20357.26.25.64/2757.26.25.65 to 57.26.25.9457.26.25.9530
20457.26.25.96/2757.26.25.97 to 57.26.25.12657.26.25.12730
20557.26.25.128/2757.26.25.129 to 57.26.25.15857.26.25.15930
20657.26.25.160/2757.26.25.161 to 57.26.25.19057.26.25.19130
20757.26.25.192/2757.26.25.193 to 57.26.25.22257.26.25.22330
20857.26.25.224/2757.26.25.225 to 57.26.25.25457.26.25.25530
20957.26.26.0/2757.26.26.1 to 57.26.26.3057.26.26.3130
21057.26.26.32/2757.26.26.33 to 57.26.26.6257.26.26.6330
21157.26.26.64/2757.26.26.65 to 57.26.26.9457.26.26.9530
21257.26.26.96/2757.26.26.97 to 57.26.26.12657.26.26.12730
21357.26.26.128/2757.26.26.129 to 57.26.26.15857.26.26.15930
21457.26.26.160/2757.26.26.161 to 57.26.26.19057.26.26.19130
21557.26.26.192/2757.26.26.193 to 57.26.26.22257.26.26.22330
21657.26.26.224/2757.26.26.225 to 57.26.26.25457.26.26.25530
21757.26.27.0/2757.26.27.1 to 57.26.27.3057.26.27.3130
21857.26.27.32/2757.26.27.33 to 57.26.27.6257.26.27.6330
21957.26.27.64/2757.26.27.65 to 57.26.27.9457.26.27.9530
22057.26.27.96/2757.26.27.97 to 57.26.27.12657.26.27.12730
22157.26.27.128/2757.26.27.129 to 57.26.27.15857.26.27.15930
22257.26.27.160/2757.26.27.161 to 57.26.27.19057.26.27.19130
22357.26.27.192/2757.26.27.193 to 57.26.27.22257.26.27.22330
22457.26.27.224/2757.26.27.225 to 57.26.27.25457.26.27.25530
22557.26.28.0/2757.26.28.1 to 57.26.28.3057.26.28.3130
22657.26.28.32/2757.26.28.33 to 57.26.28.6257.26.28.6330
22757.26.28.64/2757.26.28.65 to 57.26.28.9457.26.28.9530
22857.26.28.96/2757.26.28.97 to 57.26.28.12657.26.28.12730
22957.26.28.128/2757.26.28.129 to 57.26.28.15857.26.28.15930
23057.26.28.160/2757.26.28.161 to 57.26.28.19057.26.28.19130
23157.26.28.192/2757.26.28.193 to 57.26.28.22257.26.28.22330
23257.26.28.224/2757.26.28.225 to 57.26.28.25457.26.28.25530
23357.26.29.0/2757.26.29.1 to 57.26.29.3057.26.29.3130
23457.26.29.32/2757.26.29.33 to 57.26.29.6257.26.29.6330
23557.26.29.64/2757.26.29.65 to 57.26.29.9457.26.29.9530
23657.26.29.96/2757.26.29.97 to 57.26.29.12657.26.29.12730
23757.26.29.128/2757.26.29.129 to 57.26.29.15857.26.29.15930
23857.26.29.160/2757.26.29.161 to 57.26.29.19057.26.29.19130
23957.26.29.192/2757.26.29.193 to 57.26.29.22257.26.29.22330
24057.26.29.224/2757.26.29.225 to 57.26.29.25457.26.29.25530
24157.26.30.0/2757.26.30.1 to 57.26.30.3057.26.30.3130
24257.26.30.32/2757.26.30.33 to 57.26.30.6257.26.30.6330
24357.26.30.64/2757.26.30.65 to 57.26.30.9457.26.30.9530
24457.26.30.96/2757.26.30.97 to 57.26.30.12657.26.30.12730
24557.26.30.128/2757.26.30.129 to 57.26.30.15857.26.30.15930
24657.26.30.160/2757.26.30.161 to 57.26.30.19057.26.30.19130
24757.26.30.192/2757.26.30.193 to 57.26.30.22257.26.30.22330
24857.26.30.224/2757.26.30.225 to 57.26.30.25457.26.30.25530
24957.26.31.0/2757.26.31.1 to 57.26.31.3057.26.31.3130
25057.26.31.32/2757.26.31.33 to 57.26.31.6257.26.31.6330
25157.26.31.64/2757.26.31.65 to 57.26.31.9457.26.31.9530
25257.26.31.96/2757.26.31.97 to 57.26.31.12657.26.31.12730
25357.26.31.128/2757.26.31.129 to 57.26.31.15857.26.31.15930
25457.26.31.160/2757.26.31.161 to 57.26.31.19057.26.31.19130
25557.26.31.192/2757.26.31.193 to 57.26.31.22257.26.31.22330
25657.26.31.224/2757.26.31.225 to 57.26.31.25457.26.31.25530

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.