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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.

Network57.6.96.0/19
Usable hosts8,190
Subnet mask255.255.224.0
Addresses8,192
Network address
57.6.96.0
Broadcast address
57.6.127.255
First usable
57.6.96.1
Last usable
57.6.127.254
Usable hosts
8,190 (8,192 less the network and broadcast addresses)
Subnet mask
255.255.224.0
Wildcard mask
0.0.31.255 (Cisco ACLs, OSPF)
Prefix length
/19
Type
Public public
Old class
A (default /8)
As numbers
Hex 39066000 · Integer 956719104 to 956727295
Reverse DNS zones
96.6.57.in-addr.arpa
97.6.57.in-addr.arpa
98.6.57.in-addr.arpa
99.6.57.in-addr.arpa
100.6.57.in-addr.arpa
101.6.57.in-addr.arpa
102.6.57.in-addr.arpa
103.6.57.in-addr.arpa
104.6.57.in-addr.arpa
105.6.57.in-addr.arpa
106.6.57.in-addr.arpa
107.6.57.in-addr.arpa
108.6.57.in-addr.arpa
109.6.57.in-addr.arpa
110.6.57.in-addr.arpa
111.6.57.in-addr.arpa
and 16 more
/19 is not on a 8-bit boundary, so it takes 32 /24 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address00111001.00000110.01100000.0000000057.6.96.0
Subnet mask11111111.11111111.11100000.00000000255.255.224.0
Network00111001.00000110.01100000.0000000057.6.96.0
Broadcast00111001.00000110.01111111.1111111157.6.127.255
Split into smaller subnets/28
/20 (2)/21 (4)/22 (8)/23 (16)/24 (32)/25 (64)/26 (128)/27 (256)/28 (512)/29 (1,024)/30 (2,048)/31 (4,096)

57.6.96.0/19 makes 512 subnets of /28; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
157.6.96.0/2857.6.96.1 to 57.6.96.1457.6.96.1514
257.6.96.16/2857.6.96.17 to 57.6.96.3057.6.96.3114
357.6.96.32/2857.6.96.33 to 57.6.96.4657.6.96.4714
457.6.96.48/2857.6.96.49 to 57.6.96.6257.6.96.6314
557.6.96.64/2857.6.96.65 to 57.6.96.7857.6.96.7914
657.6.96.80/2857.6.96.81 to 57.6.96.9457.6.96.9514
757.6.96.96/2857.6.96.97 to 57.6.96.11057.6.96.11114
857.6.96.112/2857.6.96.113 to 57.6.96.12657.6.96.12714
957.6.96.128/2857.6.96.129 to 57.6.96.14257.6.96.14314
1057.6.96.144/2857.6.96.145 to 57.6.96.15857.6.96.15914
1157.6.96.160/2857.6.96.161 to 57.6.96.17457.6.96.17514
1257.6.96.176/2857.6.96.177 to 57.6.96.19057.6.96.19114
1357.6.96.192/2857.6.96.193 to 57.6.96.20657.6.96.20714
1457.6.96.208/2857.6.96.209 to 57.6.96.22257.6.96.22314
1557.6.96.224/2857.6.96.225 to 57.6.96.23857.6.96.23914
1657.6.96.240/2857.6.96.241 to 57.6.96.25457.6.96.25514
1757.6.97.0/2857.6.97.1 to 57.6.97.1457.6.97.1514
1857.6.97.16/2857.6.97.17 to 57.6.97.3057.6.97.3114
1957.6.97.32/2857.6.97.33 to 57.6.97.4657.6.97.4714
2057.6.97.48/2857.6.97.49 to 57.6.97.6257.6.97.6314
2157.6.97.64/2857.6.97.65 to 57.6.97.7857.6.97.7914
2257.6.97.80/2857.6.97.81 to 57.6.97.9457.6.97.9514
2357.6.97.96/2857.6.97.97 to 57.6.97.11057.6.97.11114
2457.6.97.112/2857.6.97.113 to 57.6.97.12657.6.97.12714
2557.6.97.128/2857.6.97.129 to 57.6.97.14257.6.97.14314
2657.6.97.144/2857.6.97.145 to 57.6.97.15857.6.97.15914
2757.6.97.160/2857.6.97.161 to 57.6.97.17457.6.97.17514
2857.6.97.176/2857.6.97.177 to 57.6.97.19057.6.97.19114
2957.6.97.192/2857.6.97.193 to 57.6.97.20657.6.97.20714
3057.6.97.208/2857.6.97.209 to 57.6.97.22257.6.97.22314
3157.6.97.224/2857.6.97.225 to 57.6.97.23857.6.97.23914
3257.6.97.240/2857.6.97.241 to 57.6.97.25457.6.97.25514
3357.6.98.0/2857.6.98.1 to 57.6.98.1457.6.98.1514
3457.6.98.16/2857.6.98.17 to 57.6.98.3057.6.98.3114
3557.6.98.32/2857.6.98.33 to 57.6.98.4657.6.98.4714
3657.6.98.48/2857.6.98.49 to 57.6.98.6257.6.98.6314
3757.6.98.64/2857.6.98.65 to 57.6.98.7857.6.98.7914
3857.6.98.80/2857.6.98.81 to 57.6.98.9457.6.98.9514
3957.6.98.96/2857.6.98.97 to 57.6.98.11057.6.98.11114
4057.6.98.112/2857.6.98.113 to 57.6.98.12657.6.98.12714
4157.6.98.128/2857.6.98.129 to 57.6.98.14257.6.98.14314
4257.6.98.144/2857.6.98.145 to 57.6.98.15857.6.98.15914
4357.6.98.160/2857.6.98.161 to 57.6.98.17457.6.98.17514
4457.6.98.176/2857.6.98.177 to 57.6.98.19057.6.98.19114
4557.6.98.192/2857.6.98.193 to 57.6.98.20657.6.98.20714
4657.6.98.208/2857.6.98.209 to 57.6.98.22257.6.98.22314
4757.6.98.224/2857.6.98.225 to 57.6.98.23857.6.98.23914
4857.6.98.240/2857.6.98.241 to 57.6.98.25457.6.98.25514
4957.6.99.0/2857.6.99.1 to 57.6.99.1457.6.99.1514
5057.6.99.16/2857.6.99.17 to 57.6.99.3057.6.99.3114
5157.6.99.32/2857.6.99.33 to 57.6.99.4657.6.99.4714
5257.6.99.48/2857.6.99.49 to 57.6.99.6257.6.99.6314
5357.6.99.64/2857.6.99.65 to 57.6.99.7857.6.99.7914
5457.6.99.80/2857.6.99.81 to 57.6.99.9457.6.99.9514
5557.6.99.96/2857.6.99.97 to 57.6.99.11057.6.99.11114
5657.6.99.112/2857.6.99.113 to 57.6.99.12657.6.99.12714
5757.6.99.128/2857.6.99.129 to 57.6.99.14257.6.99.14314
5857.6.99.144/2857.6.99.145 to 57.6.99.15857.6.99.15914
5957.6.99.160/2857.6.99.161 to 57.6.99.17457.6.99.17514
6057.6.99.176/2857.6.99.177 to 57.6.99.19057.6.99.19114
6157.6.99.192/2857.6.99.193 to 57.6.99.20657.6.99.20714
6257.6.99.208/2857.6.99.209 to 57.6.99.22257.6.99.22314
6357.6.99.224/2857.6.99.225 to 57.6.99.23857.6.99.23914
6457.6.99.240/2857.6.99.241 to 57.6.99.25457.6.99.25514
6557.6.100.0/2857.6.100.1 to 57.6.100.1457.6.100.1514
6657.6.100.16/2857.6.100.17 to 57.6.100.3057.6.100.3114
6757.6.100.32/2857.6.100.33 to 57.6.100.4657.6.100.4714
6857.6.100.48/2857.6.100.49 to 57.6.100.6257.6.100.6314
6957.6.100.64/2857.6.100.65 to 57.6.100.7857.6.100.7914
7057.6.100.80/2857.6.100.81 to 57.6.100.9457.6.100.9514
7157.6.100.96/2857.6.100.97 to 57.6.100.11057.6.100.11114
7257.6.100.112/2857.6.100.113 to 57.6.100.12657.6.100.12714
7357.6.100.128/2857.6.100.129 to 57.6.100.14257.6.100.14314
7457.6.100.144/2857.6.100.145 to 57.6.100.15857.6.100.15914
7557.6.100.160/2857.6.100.161 to 57.6.100.17457.6.100.17514
7657.6.100.176/2857.6.100.177 to 57.6.100.19057.6.100.19114
7757.6.100.192/2857.6.100.193 to 57.6.100.20657.6.100.20714
7857.6.100.208/2857.6.100.209 to 57.6.100.22257.6.100.22314
7957.6.100.224/2857.6.100.225 to 57.6.100.23857.6.100.23914
8057.6.100.240/2857.6.100.241 to 57.6.100.25457.6.100.25514
8157.6.101.0/2857.6.101.1 to 57.6.101.1457.6.101.1514
8257.6.101.16/2857.6.101.17 to 57.6.101.3057.6.101.3114
8357.6.101.32/2857.6.101.33 to 57.6.101.4657.6.101.4714
8457.6.101.48/2857.6.101.49 to 57.6.101.6257.6.101.6314
8557.6.101.64/2857.6.101.65 to 57.6.101.7857.6.101.7914
8657.6.101.80/2857.6.101.81 to 57.6.101.9457.6.101.9514
8757.6.101.96/2857.6.101.97 to 57.6.101.11057.6.101.11114
8857.6.101.112/2857.6.101.113 to 57.6.101.12657.6.101.12714
8957.6.101.128/2857.6.101.129 to 57.6.101.14257.6.101.14314
9057.6.101.144/2857.6.101.145 to 57.6.101.15857.6.101.15914
9157.6.101.160/2857.6.101.161 to 57.6.101.17457.6.101.17514
9257.6.101.176/2857.6.101.177 to 57.6.101.19057.6.101.19114
9357.6.101.192/2857.6.101.193 to 57.6.101.20657.6.101.20714
9457.6.101.208/2857.6.101.209 to 57.6.101.22257.6.101.22314
9557.6.101.224/2857.6.101.225 to 57.6.101.23857.6.101.23914
9657.6.101.240/2857.6.101.241 to 57.6.101.25457.6.101.25514
9757.6.102.0/2857.6.102.1 to 57.6.102.1457.6.102.1514
9857.6.102.16/2857.6.102.17 to 57.6.102.3057.6.102.3114
9957.6.102.32/2857.6.102.33 to 57.6.102.4657.6.102.4714
10057.6.102.48/2857.6.102.49 to 57.6.102.6257.6.102.6314
10157.6.102.64/2857.6.102.65 to 57.6.102.7857.6.102.7914
10257.6.102.80/2857.6.102.81 to 57.6.102.9457.6.102.9514
10357.6.102.96/2857.6.102.97 to 57.6.102.11057.6.102.11114
10457.6.102.112/2857.6.102.113 to 57.6.102.12657.6.102.12714
10557.6.102.128/2857.6.102.129 to 57.6.102.14257.6.102.14314
10657.6.102.144/2857.6.102.145 to 57.6.102.15857.6.102.15914
10757.6.102.160/2857.6.102.161 to 57.6.102.17457.6.102.17514
10857.6.102.176/2857.6.102.177 to 57.6.102.19057.6.102.19114
10957.6.102.192/2857.6.102.193 to 57.6.102.20657.6.102.20714
11057.6.102.208/2857.6.102.209 to 57.6.102.22257.6.102.22314
11157.6.102.224/2857.6.102.225 to 57.6.102.23857.6.102.23914
11257.6.102.240/2857.6.102.241 to 57.6.102.25457.6.102.25514
11357.6.103.0/2857.6.103.1 to 57.6.103.1457.6.103.1514
11457.6.103.16/2857.6.103.17 to 57.6.103.3057.6.103.3114
11557.6.103.32/2857.6.103.33 to 57.6.103.4657.6.103.4714
11657.6.103.48/2857.6.103.49 to 57.6.103.6257.6.103.6314
11757.6.103.64/2857.6.103.65 to 57.6.103.7857.6.103.7914
11857.6.103.80/2857.6.103.81 to 57.6.103.9457.6.103.9514
11957.6.103.96/2857.6.103.97 to 57.6.103.11057.6.103.11114
12057.6.103.112/2857.6.103.113 to 57.6.103.12657.6.103.12714
12157.6.103.128/2857.6.103.129 to 57.6.103.14257.6.103.14314
12257.6.103.144/2857.6.103.145 to 57.6.103.15857.6.103.15914
12357.6.103.160/2857.6.103.161 to 57.6.103.17457.6.103.17514
12457.6.103.176/2857.6.103.177 to 57.6.103.19057.6.103.19114
12557.6.103.192/2857.6.103.193 to 57.6.103.20657.6.103.20714
12657.6.103.208/2857.6.103.209 to 57.6.103.22257.6.103.22314
12757.6.103.224/2857.6.103.225 to 57.6.103.23857.6.103.23914
12857.6.103.240/2857.6.103.241 to 57.6.103.25457.6.103.25514
12957.6.104.0/2857.6.104.1 to 57.6.104.1457.6.104.1514
13057.6.104.16/2857.6.104.17 to 57.6.104.3057.6.104.3114
13157.6.104.32/2857.6.104.33 to 57.6.104.4657.6.104.4714
13257.6.104.48/2857.6.104.49 to 57.6.104.6257.6.104.6314
13357.6.104.64/2857.6.104.65 to 57.6.104.7857.6.104.7914
13457.6.104.80/2857.6.104.81 to 57.6.104.9457.6.104.9514
13557.6.104.96/2857.6.104.97 to 57.6.104.11057.6.104.11114
13657.6.104.112/2857.6.104.113 to 57.6.104.12657.6.104.12714
13757.6.104.128/2857.6.104.129 to 57.6.104.14257.6.104.14314
13857.6.104.144/2857.6.104.145 to 57.6.104.15857.6.104.15914
13957.6.104.160/2857.6.104.161 to 57.6.104.17457.6.104.17514
14057.6.104.176/2857.6.104.177 to 57.6.104.19057.6.104.19114
14157.6.104.192/2857.6.104.193 to 57.6.104.20657.6.104.20714
14257.6.104.208/2857.6.104.209 to 57.6.104.22257.6.104.22314
14357.6.104.224/2857.6.104.225 to 57.6.104.23857.6.104.23914
14457.6.104.240/2857.6.104.241 to 57.6.104.25457.6.104.25514
14557.6.105.0/2857.6.105.1 to 57.6.105.1457.6.105.1514
14657.6.105.16/2857.6.105.17 to 57.6.105.3057.6.105.3114
14757.6.105.32/2857.6.105.33 to 57.6.105.4657.6.105.4714
14857.6.105.48/2857.6.105.49 to 57.6.105.6257.6.105.6314
14957.6.105.64/2857.6.105.65 to 57.6.105.7857.6.105.7914
15057.6.105.80/2857.6.105.81 to 57.6.105.9457.6.105.9514
15157.6.105.96/2857.6.105.97 to 57.6.105.11057.6.105.11114
15257.6.105.112/2857.6.105.113 to 57.6.105.12657.6.105.12714
15357.6.105.128/2857.6.105.129 to 57.6.105.14257.6.105.14314
15457.6.105.144/2857.6.105.145 to 57.6.105.15857.6.105.15914
15557.6.105.160/2857.6.105.161 to 57.6.105.17457.6.105.17514
15657.6.105.176/2857.6.105.177 to 57.6.105.19057.6.105.19114
15757.6.105.192/2857.6.105.193 to 57.6.105.20657.6.105.20714
15857.6.105.208/2857.6.105.209 to 57.6.105.22257.6.105.22314
15957.6.105.224/2857.6.105.225 to 57.6.105.23857.6.105.23914
16057.6.105.240/2857.6.105.241 to 57.6.105.25457.6.105.25514
16157.6.106.0/2857.6.106.1 to 57.6.106.1457.6.106.1514
16257.6.106.16/2857.6.106.17 to 57.6.106.3057.6.106.3114
16357.6.106.32/2857.6.106.33 to 57.6.106.4657.6.106.4714
16457.6.106.48/2857.6.106.49 to 57.6.106.6257.6.106.6314
16557.6.106.64/2857.6.106.65 to 57.6.106.7857.6.106.7914
16657.6.106.80/2857.6.106.81 to 57.6.106.9457.6.106.9514
16757.6.106.96/2857.6.106.97 to 57.6.106.11057.6.106.11114
16857.6.106.112/2857.6.106.113 to 57.6.106.12657.6.106.12714
16957.6.106.128/2857.6.106.129 to 57.6.106.14257.6.106.14314
17057.6.106.144/2857.6.106.145 to 57.6.106.15857.6.106.15914
17157.6.106.160/2857.6.106.161 to 57.6.106.17457.6.106.17514
17257.6.106.176/2857.6.106.177 to 57.6.106.19057.6.106.19114
17357.6.106.192/2857.6.106.193 to 57.6.106.20657.6.106.20714
17457.6.106.208/2857.6.106.209 to 57.6.106.22257.6.106.22314
17557.6.106.224/2857.6.106.225 to 57.6.106.23857.6.106.23914
17657.6.106.240/2857.6.106.241 to 57.6.106.25457.6.106.25514
17757.6.107.0/2857.6.107.1 to 57.6.107.1457.6.107.1514
17857.6.107.16/2857.6.107.17 to 57.6.107.3057.6.107.3114
17957.6.107.32/2857.6.107.33 to 57.6.107.4657.6.107.4714
18057.6.107.48/2857.6.107.49 to 57.6.107.6257.6.107.6314
18157.6.107.64/2857.6.107.65 to 57.6.107.7857.6.107.7914
18257.6.107.80/2857.6.107.81 to 57.6.107.9457.6.107.9514
18357.6.107.96/2857.6.107.97 to 57.6.107.11057.6.107.11114
18457.6.107.112/2857.6.107.113 to 57.6.107.12657.6.107.12714
18557.6.107.128/2857.6.107.129 to 57.6.107.14257.6.107.14314
18657.6.107.144/2857.6.107.145 to 57.6.107.15857.6.107.15914
18757.6.107.160/2857.6.107.161 to 57.6.107.17457.6.107.17514
18857.6.107.176/2857.6.107.177 to 57.6.107.19057.6.107.19114
18957.6.107.192/2857.6.107.193 to 57.6.107.20657.6.107.20714
19057.6.107.208/2857.6.107.209 to 57.6.107.22257.6.107.22314
19157.6.107.224/2857.6.107.225 to 57.6.107.23857.6.107.23914
19257.6.107.240/2857.6.107.241 to 57.6.107.25457.6.107.25514
19357.6.108.0/2857.6.108.1 to 57.6.108.1457.6.108.1514
19457.6.108.16/2857.6.108.17 to 57.6.108.3057.6.108.3114
19557.6.108.32/2857.6.108.33 to 57.6.108.4657.6.108.4714
19657.6.108.48/2857.6.108.49 to 57.6.108.6257.6.108.6314
19757.6.108.64/2857.6.108.65 to 57.6.108.7857.6.108.7914
19857.6.108.80/2857.6.108.81 to 57.6.108.9457.6.108.9514
19957.6.108.96/2857.6.108.97 to 57.6.108.11057.6.108.11114
20057.6.108.112/2857.6.108.113 to 57.6.108.12657.6.108.12714
20157.6.108.128/2857.6.108.129 to 57.6.108.14257.6.108.14314
20257.6.108.144/2857.6.108.145 to 57.6.108.15857.6.108.15914
20357.6.108.160/2857.6.108.161 to 57.6.108.17457.6.108.17514
20457.6.108.176/2857.6.108.177 to 57.6.108.19057.6.108.19114
20557.6.108.192/2857.6.108.193 to 57.6.108.20657.6.108.20714
20657.6.108.208/2857.6.108.209 to 57.6.108.22257.6.108.22314
20757.6.108.224/2857.6.108.225 to 57.6.108.23857.6.108.23914
20857.6.108.240/2857.6.108.241 to 57.6.108.25457.6.108.25514
20957.6.109.0/2857.6.109.1 to 57.6.109.1457.6.109.1514
21057.6.109.16/2857.6.109.17 to 57.6.109.3057.6.109.3114
21157.6.109.32/2857.6.109.33 to 57.6.109.4657.6.109.4714
21257.6.109.48/2857.6.109.49 to 57.6.109.6257.6.109.6314
21357.6.109.64/2857.6.109.65 to 57.6.109.7857.6.109.7914
21457.6.109.80/2857.6.109.81 to 57.6.109.9457.6.109.9514
21557.6.109.96/2857.6.109.97 to 57.6.109.11057.6.109.11114
21657.6.109.112/2857.6.109.113 to 57.6.109.12657.6.109.12714
21757.6.109.128/2857.6.109.129 to 57.6.109.14257.6.109.14314
21857.6.109.144/2857.6.109.145 to 57.6.109.15857.6.109.15914
21957.6.109.160/2857.6.109.161 to 57.6.109.17457.6.109.17514
22057.6.109.176/2857.6.109.177 to 57.6.109.19057.6.109.19114
22157.6.109.192/2857.6.109.193 to 57.6.109.20657.6.109.20714
22257.6.109.208/2857.6.109.209 to 57.6.109.22257.6.109.22314
22357.6.109.224/2857.6.109.225 to 57.6.109.23857.6.109.23914
22457.6.109.240/2857.6.109.241 to 57.6.109.25457.6.109.25514
22557.6.110.0/2857.6.110.1 to 57.6.110.1457.6.110.1514
22657.6.110.16/2857.6.110.17 to 57.6.110.3057.6.110.3114
22757.6.110.32/2857.6.110.33 to 57.6.110.4657.6.110.4714
22857.6.110.48/2857.6.110.49 to 57.6.110.6257.6.110.6314
22957.6.110.64/2857.6.110.65 to 57.6.110.7857.6.110.7914
23057.6.110.80/2857.6.110.81 to 57.6.110.9457.6.110.9514
23157.6.110.96/2857.6.110.97 to 57.6.110.11057.6.110.11114
23257.6.110.112/2857.6.110.113 to 57.6.110.12657.6.110.12714
23357.6.110.128/2857.6.110.129 to 57.6.110.14257.6.110.14314
23457.6.110.144/2857.6.110.145 to 57.6.110.15857.6.110.15914
23557.6.110.160/2857.6.110.161 to 57.6.110.17457.6.110.17514
23657.6.110.176/2857.6.110.177 to 57.6.110.19057.6.110.19114
23757.6.110.192/2857.6.110.193 to 57.6.110.20657.6.110.20714
23857.6.110.208/2857.6.110.209 to 57.6.110.22257.6.110.22314
23957.6.110.224/2857.6.110.225 to 57.6.110.23857.6.110.23914
24057.6.110.240/2857.6.110.241 to 57.6.110.25457.6.110.25514
24157.6.111.0/2857.6.111.1 to 57.6.111.1457.6.111.1514
24257.6.111.16/2857.6.111.17 to 57.6.111.3057.6.111.3114
24357.6.111.32/2857.6.111.33 to 57.6.111.4657.6.111.4714
24457.6.111.48/2857.6.111.49 to 57.6.111.6257.6.111.6314
24557.6.111.64/2857.6.111.65 to 57.6.111.7857.6.111.7914
24657.6.111.80/2857.6.111.81 to 57.6.111.9457.6.111.9514
24757.6.111.96/2857.6.111.97 to 57.6.111.11057.6.111.11114
24857.6.111.112/2857.6.111.113 to 57.6.111.12657.6.111.12714
24957.6.111.128/2857.6.111.129 to 57.6.111.14257.6.111.14314
25057.6.111.144/2857.6.111.145 to 57.6.111.15857.6.111.15914
25157.6.111.160/2857.6.111.161 to 57.6.111.17457.6.111.17514
25257.6.111.176/2857.6.111.177 to 57.6.111.19057.6.111.19114
25357.6.111.192/2857.6.111.193 to 57.6.111.20657.6.111.20714
25457.6.111.208/2857.6.111.209 to 57.6.111.22257.6.111.22314
25557.6.111.224/2857.6.111.225 to 57.6.111.23857.6.111.23914
25657.6.111.240/2857.6.111.241 to 57.6.111.25457.6.111.25514

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.