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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.

Network75.167.0.0/16
Usable hosts65,534
Subnet mask255.255.0.0
Addresses65,536
Network address
75.167.0.0
Broadcast address
75.167.255.255
First usable
75.167.0.1
Last usable
75.167.255.254
Usable hosts
65,534 (65,536 less the network and broadcast addresses)
Subnet mask
255.255.0.0
Wildcard mask
0.0.255.255 (Cisco ACLs, OSPF)
Prefix length
/16
Type
Public public
Old class
A (default /8)
As numbers
Hex 4BA70000 · Integer 1269235712 to 1269301247
Reverse DNS zone
167.75.in-addr.arpa
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address01001011.10100111..00000000.0000000075.167.0.0
Subnet mask11111111.11111111..00000000.00000000255.255.0.0
Network01001011.10100111..00000000.0000000075.167.0.0
Broadcast01001011.10100111..11111111.1111111175.167.255.255
Split into smaller subnets/28
/17 (2)/18 (4)/19 (8)/20 (16)/21 (32)/22 (64)/23 (128)/24 (256)/25 (512)/26 (1,024)/27 (2,048)/28 (4,096)

75.167.0.0/16 makes 4,096 subnets of /28; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
175.167.0.0/2875.167.0.1 to 75.167.0.1475.167.0.1514
275.167.0.16/2875.167.0.17 to 75.167.0.3075.167.0.3114
375.167.0.32/2875.167.0.33 to 75.167.0.4675.167.0.4714
475.167.0.48/2875.167.0.49 to 75.167.0.6275.167.0.6314
575.167.0.64/2875.167.0.65 to 75.167.0.7875.167.0.7914
675.167.0.80/2875.167.0.81 to 75.167.0.9475.167.0.9514
775.167.0.96/2875.167.0.97 to 75.167.0.11075.167.0.11114
875.167.0.112/2875.167.0.113 to 75.167.0.12675.167.0.12714
975.167.0.128/2875.167.0.129 to 75.167.0.14275.167.0.14314
1075.167.0.144/2875.167.0.145 to 75.167.0.15875.167.0.15914
1175.167.0.160/2875.167.0.161 to 75.167.0.17475.167.0.17514
1275.167.0.176/2875.167.0.177 to 75.167.0.19075.167.0.19114
1375.167.0.192/2875.167.0.193 to 75.167.0.20675.167.0.20714
1475.167.0.208/2875.167.0.209 to 75.167.0.22275.167.0.22314
1575.167.0.224/2875.167.0.225 to 75.167.0.23875.167.0.23914
1675.167.0.240/2875.167.0.241 to 75.167.0.25475.167.0.25514
1775.167.1.0/2875.167.1.1 to 75.167.1.1475.167.1.1514
1875.167.1.16/2875.167.1.17 to 75.167.1.3075.167.1.3114
1975.167.1.32/2875.167.1.33 to 75.167.1.4675.167.1.4714
2075.167.1.48/2875.167.1.49 to 75.167.1.6275.167.1.6314
2175.167.1.64/2875.167.1.65 to 75.167.1.7875.167.1.7914
2275.167.1.80/2875.167.1.81 to 75.167.1.9475.167.1.9514
2375.167.1.96/2875.167.1.97 to 75.167.1.11075.167.1.11114
2475.167.1.112/2875.167.1.113 to 75.167.1.12675.167.1.12714
2575.167.1.128/2875.167.1.129 to 75.167.1.14275.167.1.14314
2675.167.1.144/2875.167.1.145 to 75.167.1.15875.167.1.15914
2775.167.1.160/2875.167.1.161 to 75.167.1.17475.167.1.17514
2875.167.1.176/2875.167.1.177 to 75.167.1.19075.167.1.19114
2975.167.1.192/2875.167.1.193 to 75.167.1.20675.167.1.20714
3075.167.1.208/2875.167.1.209 to 75.167.1.22275.167.1.22314
3175.167.1.224/2875.167.1.225 to 75.167.1.23875.167.1.23914
3275.167.1.240/2875.167.1.241 to 75.167.1.25475.167.1.25514
3375.167.2.0/2875.167.2.1 to 75.167.2.1475.167.2.1514
3475.167.2.16/2875.167.2.17 to 75.167.2.3075.167.2.3114
3575.167.2.32/2875.167.2.33 to 75.167.2.4675.167.2.4714
3675.167.2.48/2875.167.2.49 to 75.167.2.6275.167.2.6314
3775.167.2.64/2875.167.2.65 to 75.167.2.7875.167.2.7914
3875.167.2.80/2875.167.2.81 to 75.167.2.9475.167.2.9514
3975.167.2.96/2875.167.2.97 to 75.167.2.11075.167.2.11114
4075.167.2.112/2875.167.2.113 to 75.167.2.12675.167.2.12714
4175.167.2.128/2875.167.2.129 to 75.167.2.14275.167.2.14314
4275.167.2.144/2875.167.2.145 to 75.167.2.15875.167.2.15914
4375.167.2.160/2875.167.2.161 to 75.167.2.17475.167.2.17514
4475.167.2.176/2875.167.2.177 to 75.167.2.19075.167.2.19114
4575.167.2.192/2875.167.2.193 to 75.167.2.20675.167.2.20714
4675.167.2.208/2875.167.2.209 to 75.167.2.22275.167.2.22314
4775.167.2.224/2875.167.2.225 to 75.167.2.23875.167.2.23914
4875.167.2.240/2875.167.2.241 to 75.167.2.25475.167.2.25514
4975.167.3.0/2875.167.3.1 to 75.167.3.1475.167.3.1514
5075.167.3.16/2875.167.3.17 to 75.167.3.3075.167.3.3114
5175.167.3.32/2875.167.3.33 to 75.167.3.4675.167.3.4714
5275.167.3.48/2875.167.3.49 to 75.167.3.6275.167.3.6314
5375.167.3.64/2875.167.3.65 to 75.167.3.7875.167.3.7914
5475.167.3.80/2875.167.3.81 to 75.167.3.9475.167.3.9514
5575.167.3.96/2875.167.3.97 to 75.167.3.11075.167.3.11114
5675.167.3.112/2875.167.3.113 to 75.167.3.12675.167.3.12714
5775.167.3.128/2875.167.3.129 to 75.167.3.14275.167.3.14314
5875.167.3.144/2875.167.3.145 to 75.167.3.15875.167.3.15914
5975.167.3.160/2875.167.3.161 to 75.167.3.17475.167.3.17514
6075.167.3.176/2875.167.3.177 to 75.167.3.19075.167.3.19114
6175.167.3.192/2875.167.3.193 to 75.167.3.20675.167.3.20714
6275.167.3.208/2875.167.3.209 to 75.167.3.22275.167.3.22314
6375.167.3.224/2875.167.3.225 to 75.167.3.23875.167.3.23914
6475.167.3.240/2875.167.3.241 to 75.167.3.25475.167.3.25514
6575.167.4.0/2875.167.4.1 to 75.167.4.1475.167.4.1514
6675.167.4.16/2875.167.4.17 to 75.167.4.3075.167.4.3114
6775.167.4.32/2875.167.4.33 to 75.167.4.4675.167.4.4714
6875.167.4.48/2875.167.4.49 to 75.167.4.6275.167.4.6314
6975.167.4.64/2875.167.4.65 to 75.167.4.7875.167.4.7914
7075.167.4.80/2875.167.4.81 to 75.167.4.9475.167.4.9514
7175.167.4.96/2875.167.4.97 to 75.167.4.11075.167.4.11114
7275.167.4.112/2875.167.4.113 to 75.167.4.12675.167.4.12714
7375.167.4.128/2875.167.4.129 to 75.167.4.14275.167.4.14314
7475.167.4.144/2875.167.4.145 to 75.167.4.15875.167.4.15914
7575.167.4.160/2875.167.4.161 to 75.167.4.17475.167.4.17514
7675.167.4.176/2875.167.4.177 to 75.167.4.19075.167.4.19114
7775.167.4.192/2875.167.4.193 to 75.167.4.20675.167.4.20714
7875.167.4.208/2875.167.4.209 to 75.167.4.22275.167.4.22314
7975.167.4.224/2875.167.4.225 to 75.167.4.23875.167.4.23914
8075.167.4.240/2875.167.4.241 to 75.167.4.25475.167.4.25514
8175.167.5.0/2875.167.5.1 to 75.167.5.1475.167.5.1514
8275.167.5.16/2875.167.5.17 to 75.167.5.3075.167.5.3114
8375.167.5.32/2875.167.5.33 to 75.167.5.4675.167.5.4714
8475.167.5.48/2875.167.5.49 to 75.167.5.6275.167.5.6314
8575.167.5.64/2875.167.5.65 to 75.167.5.7875.167.5.7914
8675.167.5.80/2875.167.5.81 to 75.167.5.9475.167.5.9514
8775.167.5.96/2875.167.5.97 to 75.167.5.11075.167.5.11114
8875.167.5.112/2875.167.5.113 to 75.167.5.12675.167.5.12714
8975.167.5.128/2875.167.5.129 to 75.167.5.14275.167.5.14314
9075.167.5.144/2875.167.5.145 to 75.167.5.15875.167.5.15914
9175.167.5.160/2875.167.5.161 to 75.167.5.17475.167.5.17514
9275.167.5.176/2875.167.5.177 to 75.167.5.19075.167.5.19114
9375.167.5.192/2875.167.5.193 to 75.167.5.20675.167.5.20714
9475.167.5.208/2875.167.5.209 to 75.167.5.22275.167.5.22314
9575.167.5.224/2875.167.5.225 to 75.167.5.23875.167.5.23914
9675.167.5.240/2875.167.5.241 to 75.167.5.25475.167.5.25514
9775.167.6.0/2875.167.6.1 to 75.167.6.1475.167.6.1514
9875.167.6.16/2875.167.6.17 to 75.167.6.3075.167.6.3114
9975.167.6.32/2875.167.6.33 to 75.167.6.4675.167.6.4714
10075.167.6.48/2875.167.6.49 to 75.167.6.6275.167.6.6314
10175.167.6.64/2875.167.6.65 to 75.167.6.7875.167.6.7914
10275.167.6.80/2875.167.6.81 to 75.167.6.9475.167.6.9514
10375.167.6.96/2875.167.6.97 to 75.167.6.11075.167.6.11114
10475.167.6.112/2875.167.6.113 to 75.167.6.12675.167.6.12714
10575.167.6.128/2875.167.6.129 to 75.167.6.14275.167.6.14314
10675.167.6.144/2875.167.6.145 to 75.167.6.15875.167.6.15914
10775.167.6.160/2875.167.6.161 to 75.167.6.17475.167.6.17514
10875.167.6.176/2875.167.6.177 to 75.167.6.19075.167.6.19114
10975.167.6.192/2875.167.6.193 to 75.167.6.20675.167.6.20714
11075.167.6.208/2875.167.6.209 to 75.167.6.22275.167.6.22314
11175.167.6.224/2875.167.6.225 to 75.167.6.23875.167.6.23914
11275.167.6.240/2875.167.6.241 to 75.167.6.25475.167.6.25514
11375.167.7.0/2875.167.7.1 to 75.167.7.1475.167.7.1514
11475.167.7.16/2875.167.7.17 to 75.167.7.3075.167.7.3114
11575.167.7.32/2875.167.7.33 to 75.167.7.4675.167.7.4714
11675.167.7.48/2875.167.7.49 to 75.167.7.6275.167.7.6314
11775.167.7.64/2875.167.7.65 to 75.167.7.7875.167.7.7914
11875.167.7.80/2875.167.7.81 to 75.167.7.9475.167.7.9514
11975.167.7.96/2875.167.7.97 to 75.167.7.11075.167.7.11114
12075.167.7.112/2875.167.7.113 to 75.167.7.12675.167.7.12714
12175.167.7.128/2875.167.7.129 to 75.167.7.14275.167.7.14314
12275.167.7.144/2875.167.7.145 to 75.167.7.15875.167.7.15914
12375.167.7.160/2875.167.7.161 to 75.167.7.17475.167.7.17514
12475.167.7.176/2875.167.7.177 to 75.167.7.19075.167.7.19114
12575.167.7.192/2875.167.7.193 to 75.167.7.20675.167.7.20714
12675.167.7.208/2875.167.7.209 to 75.167.7.22275.167.7.22314
12775.167.7.224/2875.167.7.225 to 75.167.7.23875.167.7.23914
12875.167.7.240/2875.167.7.241 to 75.167.7.25475.167.7.25514
12975.167.8.0/2875.167.8.1 to 75.167.8.1475.167.8.1514
13075.167.8.16/2875.167.8.17 to 75.167.8.3075.167.8.3114
13175.167.8.32/2875.167.8.33 to 75.167.8.4675.167.8.4714
13275.167.8.48/2875.167.8.49 to 75.167.8.6275.167.8.6314
13375.167.8.64/2875.167.8.65 to 75.167.8.7875.167.8.7914
13475.167.8.80/2875.167.8.81 to 75.167.8.9475.167.8.9514
13575.167.8.96/2875.167.8.97 to 75.167.8.11075.167.8.11114
13675.167.8.112/2875.167.8.113 to 75.167.8.12675.167.8.12714
13775.167.8.128/2875.167.8.129 to 75.167.8.14275.167.8.14314
13875.167.8.144/2875.167.8.145 to 75.167.8.15875.167.8.15914
13975.167.8.160/2875.167.8.161 to 75.167.8.17475.167.8.17514
14075.167.8.176/2875.167.8.177 to 75.167.8.19075.167.8.19114
14175.167.8.192/2875.167.8.193 to 75.167.8.20675.167.8.20714
14275.167.8.208/2875.167.8.209 to 75.167.8.22275.167.8.22314
14375.167.8.224/2875.167.8.225 to 75.167.8.23875.167.8.23914
14475.167.8.240/2875.167.8.241 to 75.167.8.25475.167.8.25514
14575.167.9.0/2875.167.9.1 to 75.167.9.1475.167.9.1514
14675.167.9.16/2875.167.9.17 to 75.167.9.3075.167.9.3114
14775.167.9.32/2875.167.9.33 to 75.167.9.4675.167.9.4714
14875.167.9.48/2875.167.9.49 to 75.167.9.6275.167.9.6314
14975.167.9.64/2875.167.9.65 to 75.167.9.7875.167.9.7914
15075.167.9.80/2875.167.9.81 to 75.167.9.9475.167.9.9514
15175.167.9.96/2875.167.9.97 to 75.167.9.11075.167.9.11114
15275.167.9.112/2875.167.9.113 to 75.167.9.12675.167.9.12714
15375.167.9.128/2875.167.9.129 to 75.167.9.14275.167.9.14314
15475.167.9.144/2875.167.9.145 to 75.167.9.15875.167.9.15914
15575.167.9.160/2875.167.9.161 to 75.167.9.17475.167.9.17514
15675.167.9.176/2875.167.9.177 to 75.167.9.19075.167.9.19114
15775.167.9.192/2875.167.9.193 to 75.167.9.20675.167.9.20714
15875.167.9.208/2875.167.9.209 to 75.167.9.22275.167.9.22314
15975.167.9.224/2875.167.9.225 to 75.167.9.23875.167.9.23914
16075.167.9.240/2875.167.9.241 to 75.167.9.25475.167.9.25514
16175.167.10.0/2875.167.10.1 to 75.167.10.1475.167.10.1514
16275.167.10.16/2875.167.10.17 to 75.167.10.3075.167.10.3114
16375.167.10.32/2875.167.10.33 to 75.167.10.4675.167.10.4714
16475.167.10.48/2875.167.10.49 to 75.167.10.6275.167.10.6314
16575.167.10.64/2875.167.10.65 to 75.167.10.7875.167.10.7914
16675.167.10.80/2875.167.10.81 to 75.167.10.9475.167.10.9514
16775.167.10.96/2875.167.10.97 to 75.167.10.11075.167.10.11114
16875.167.10.112/2875.167.10.113 to 75.167.10.12675.167.10.12714
16975.167.10.128/2875.167.10.129 to 75.167.10.14275.167.10.14314
17075.167.10.144/2875.167.10.145 to 75.167.10.15875.167.10.15914
17175.167.10.160/2875.167.10.161 to 75.167.10.17475.167.10.17514
17275.167.10.176/2875.167.10.177 to 75.167.10.19075.167.10.19114
17375.167.10.192/2875.167.10.193 to 75.167.10.20675.167.10.20714
17475.167.10.208/2875.167.10.209 to 75.167.10.22275.167.10.22314
17575.167.10.224/2875.167.10.225 to 75.167.10.23875.167.10.23914
17675.167.10.240/2875.167.10.241 to 75.167.10.25475.167.10.25514
17775.167.11.0/2875.167.11.1 to 75.167.11.1475.167.11.1514
17875.167.11.16/2875.167.11.17 to 75.167.11.3075.167.11.3114
17975.167.11.32/2875.167.11.33 to 75.167.11.4675.167.11.4714
18075.167.11.48/2875.167.11.49 to 75.167.11.6275.167.11.6314
18175.167.11.64/2875.167.11.65 to 75.167.11.7875.167.11.7914
18275.167.11.80/2875.167.11.81 to 75.167.11.9475.167.11.9514
18375.167.11.96/2875.167.11.97 to 75.167.11.11075.167.11.11114
18475.167.11.112/2875.167.11.113 to 75.167.11.12675.167.11.12714
18575.167.11.128/2875.167.11.129 to 75.167.11.14275.167.11.14314
18675.167.11.144/2875.167.11.145 to 75.167.11.15875.167.11.15914
18775.167.11.160/2875.167.11.161 to 75.167.11.17475.167.11.17514
18875.167.11.176/2875.167.11.177 to 75.167.11.19075.167.11.19114
18975.167.11.192/2875.167.11.193 to 75.167.11.20675.167.11.20714
19075.167.11.208/2875.167.11.209 to 75.167.11.22275.167.11.22314
19175.167.11.224/2875.167.11.225 to 75.167.11.23875.167.11.23914
19275.167.11.240/2875.167.11.241 to 75.167.11.25475.167.11.25514
19375.167.12.0/2875.167.12.1 to 75.167.12.1475.167.12.1514
19475.167.12.16/2875.167.12.17 to 75.167.12.3075.167.12.3114
19575.167.12.32/2875.167.12.33 to 75.167.12.4675.167.12.4714
19675.167.12.48/2875.167.12.49 to 75.167.12.6275.167.12.6314
19775.167.12.64/2875.167.12.65 to 75.167.12.7875.167.12.7914
19875.167.12.80/2875.167.12.81 to 75.167.12.9475.167.12.9514
19975.167.12.96/2875.167.12.97 to 75.167.12.11075.167.12.11114
20075.167.12.112/2875.167.12.113 to 75.167.12.12675.167.12.12714
20175.167.12.128/2875.167.12.129 to 75.167.12.14275.167.12.14314
20275.167.12.144/2875.167.12.145 to 75.167.12.15875.167.12.15914
20375.167.12.160/2875.167.12.161 to 75.167.12.17475.167.12.17514
20475.167.12.176/2875.167.12.177 to 75.167.12.19075.167.12.19114
20575.167.12.192/2875.167.12.193 to 75.167.12.20675.167.12.20714
20675.167.12.208/2875.167.12.209 to 75.167.12.22275.167.12.22314
20775.167.12.224/2875.167.12.225 to 75.167.12.23875.167.12.23914
20875.167.12.240/2875.167.12.241 to 75.167.12.25475.167.12.25514
20975.167.13.0/2875.167.13.1 to 75.167.13.1475.167.13.1514
21075.167.13.16/2875.167.13.17 to 75.167.13.3075.167.13.3114
21175.167.13.32/2875.167.13.33 to 75.167.13.4675.167.13.4714
21275.167.13.48/2875.167.13.49 to 75.167.13.6275.167.13.6314
21375.167.13.64/2875.167.13.65 to 75.167.13.7875.167.13.7914
21475.167.13.80/2875.167.13.81 to 75.167.13.9475.167.13.9514
21575.167.13.96/2875.167.13.97 to 75.167.13.11075.167.13.11114
21675.167.13.112/2875.167.13.113 to 75.167.13.12675.167.13.12714
21775.167.13.128/2875.167.13.129 to 75.167.13.14275.167.13.14314
21875.167.13.144/2875.167.13.145 to 75.167.13.15875.167.13.15914
21975.167.13.160/2875.167.13.161 to 75.167.13.17475.167.13.17514
22075.167.13.176/2875.167.13.177 to 75.167.13.19075.167.13.19114
22175.167.13.192/2875.167.13.193 to 75.167.13.20675.167.13.20714
22275.167.13.208/2875.167.13.209 to 75.167.13.22275.167.13.22314
22375.167.13.224/2875.167.13.225 to 75.167.13.23875.167.13.23914
22475.167.13.240/2875.167.13.241 to 75.167.13.25475.167.13.25514
22575.167.14.0/2875.167.14.1 to 75.167.14.1475.167.14.1514
22675.167.14.16/2875.167.14.17 to 75.167.14.3075.167.14.3114
22775.167.14.32/2875.167.14.33 to 75.167.14.4675.167.14.4714
22875.167.14.48/2875.167.14.49 to 75.167.14.6275.167.14.6314
22975.167.14.64/2875.167.14.65 to 75.167.14.7875.167.14.7914
23075.167.14.80/2875.167.14.81 to 75.167.14.9475.167.14.9514
23175.167.14.96/2875.167.14.97 to 75.167.14.11075.167.14.11114
23275.167.14.112/2875.167.14.113 to 75.167.14.12675.167.14.12714
23375.167.14.128/2875.167.14.129 to 75.167.14.14275.167.14.14314
23475.167.14.144/2875.167.14.145 to 75.167.14.15875.167.14.15914
23575.167.14.160/2875.167.14.161 to 75.167.14.17475.167.14.17514
23675.167.14.176/2875.167.14.177 to 75.167.14.19075.167.14.19114
23775.167.14.192/2875.167.14.193 to 75.167.14.20675.167.14.20714
23875.167.14.208/2875.167.14.209 to 75.167.14.22275.167.14.22314
23975.167.14.224/2875.167.14.225 to 75.167.14.23875.167.14.23914
24075.167.14.240/2875.167.14.241 to 75.167.14.25475.167.14.25514
24175.167.15.0/2875.167.15.1 to 75.167.15.1475.167.15.1514
24275.167.15.16/2875.167.15.17 to 75.167.15.3075.167.15.3114
24375.167.15.32/2875.167.15.33 to 75.167.15.4675.167.15.4714
24475.167.15.48/2875.167.15.49 to 75.167.15.6275.167.15.6314
24575.167.15.64/2875.167.15.65 to 75.167.15.7875.167.15.7914
24675.167.15.80/2875.167.15.81 to 75.167.15.9475.167.15.9514
24775.167.15.96/2875.167.15.97 to 75.167.15.11075.167.15.11114
24875.167.15.112/2875.167.15.113 to 75.167.15.12675.167.15.12714
24975.167.15.128/2875.167.15.129 to 75.167.15.14275.167.15.14314
25075.167.15.144/2875.167.15.145 to 75.167.15.15875.167.15.15914
25175.167.15.160/2875.167.15.161 to 75.167.15.17475.167.15.17514
25275.167.15.176/2875.167.15.177 to 75.167.15.19075.167.15.19114
25375.167.15.192/2875.167.15.193 to 75.167.15.20675.167.15.20714
25475.167.15.208/2875.167.15.209 to 75.167.15.22275.167.15.22314
25575.167.15.224/2875.167.15.225 to 75.167.15.23875.167.15.23914
25675.167.15.240/2875.167.15.241 to 75.167.15.25475.167.15.25514

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.