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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.

Network92.3.192.0/19
Usable hosts8,190
Subnet mask255.255.224.0
Addresses8,192
Network address
92.3.192.0
Broadcast address
92.3.223.255
First usable
92.3.192.1
Last usable
92.3.223.254
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 5C03C000 · Integer 1543749632 to 1543757823
Reverse DNS zones
192.3.92.in-addr.arpa
193.3.92.in-addr.arpa
194.3.92.in-addr.arpa
195.3.92.in-addr.arpa
196.3.92.in-addr.arpa
197.3.92.in-addr.arpa
198.3.92.in-addr.arpa
199.3.92.in-addr.arpa
200.3.92.in-addr.arpa
201.3.92.in-addr.arpa
202.3.92.in-addr.arpa
203.3.92.in-addr.arpa
204.3.92.in-addr.arpa
205.3.92.in-addr.arpa
206.3.92.in-addr.arpa
207.3.92.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
Address01011100.00000011.11000000.0000000092.3.192.0
Subnet mask11111111.11111111.11100000.00000000255.255.224.0
Network01011100.00000011.11000000.0000000092.3.192.0
Broadcast01011100.00000011.11011111.1111111192.3.223.255
Split into smaller subnets/29
/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)

92.3.192.0/19 makes 1,024 subnets of /29; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
192.3.192.0/2992.3.192.1 to 92.3.192.692.3.192.76
292.3.192.8/2992.3.192.9 to 92.3.192.1492.3.192.156
392.3.192.16/2992.3.192.17 to 92.3.192.2292.3.192.236
492.3.192.24/2992.3.192.25 to 92.3.192.3092.3.192.316
592.3.192.32/2992.3.192.33 to 92.3.192.3892.3.192.396
692.3.192.40/2992.3.192.41 to 92.3.192.4692.3.192.476
792.3.192.48/2992.3.192.49 to 92.3.192.5492.3.192.556
892.3.192.56/2992.3.192.57 to 92.3.192.6292.3.192.636
992.3.192.64/2992.3.192.65 to 92.3.192.7092.3.192.716
1092.3.192.72/2992.3.192.73 to 92.3.192.7892.3.192.796
1192.3.192.80/2992.3.192.81 to 92.3.192.8692.3.192.876
1292.3.192.88/2992.3.192.89 to 92.3.192.9492.3.192.956
1392.3.192.96/2992.3.192.97 to 92.3.192.10292.3.192.1036
1492.3.192.104/2992.3.192.105 to 92.3.192.11092.3.192.1116
1592.3.192.112/2992.3.192.113 to 92.3.192.11892.3.192.1196
1692.3.192.120/2992.3.192.121 to 92.3.192.12692.3.192.1276
1792.3.192.128/2992.3.192.129 to 92.3.192.13492.3.192.1356
1892.3.192.136/2992.3.192.137 to 92.3.192.14292.3.192.1436
1992.3.192.144/2992.3.192.145 to 92.3.192.15092.3.192.1516
2092.3.192.152/2992.3.192.153 to 92.3.192.15892.3.192.1596
2192.3.192.160/2992.3.192.161 to 92.3.192.16692.3.192.1676
2292.3.192.168/2992.3.192.169 to 92.3.192.17492.3.192.1756
2392.3.192.176/2992.3.192.177 to 92.3.192.18292.3.192.1836
2492.3.192.184/2992.3.192.185 to 92.3.192.19092.3.192.1916
2592.3.192.192/2992.3.192.193 to 92.3.192.19892.3.192.1996
2692.3.192.200/2992.3.192.201 to 92.3.192.20692.3.192.2076
2792.3.192.208/2992.3.192.209 to 92.3.192.21492.3.192.2156
2892.3.192.216/2992.3.192.217 to 92.3.192.22292.3.192.2236
2992.3.192.224/2992.3.192.225 to 92.3.192.23092.3.192.2316
3092.3.192.232/2992.3.192.233 to 92.3.192.23892.3.192.2396
3192.3.192.240/2992.3.192.241 to 92.3.192.24692.3.192.2476
3292.3.192.248/2992.3.192.249 to 92.3.192.25492.3.192.2556
3392.3.193.0/2992.3.193.1 to 92.3.193.692.3.193.76
3492.3.193.8/2992.3.193.9 to 92.3.193.1492.3.193.156
3592.3.193.16/2992.3.193.17 to 92.3.193.2292.3.193.236
3692.3.193.24/2992.3.193.25 to 92.3.193.3092.3.193.316
3792.3.193.32/2992.3.193.33 to 92.3.193.3892.3.193.396
3892.3.193.40/2992.3.193.41 to 92.3.193.4692.3.193.476
3992.3.193.48/2992.3.193.49 to 92.3.193.5492.3.193.556
4092.3.193.56/2992.3.193.57 to 92.3.193.6292.3.193.636
4192.3.193.64/2992.3.193.65 to 92.3.193.7092.3.193.716
4292.3.193.72/2992.3.193.73 to 92.3.193.7892.3.193.796
4392.3.193.80/2992.3.193.81 to 92.3.193.8692.3.193.876
4492.3.193.88/2992.3.193.89 to 92.3.193.9492.3.193.956
4592.3.193.96/2992.3.193.97 to 92.3.193.10292.3.193.1036
4692.3.193.104/2992.3.193.105 to 92.3.193.11092.3.193.1116
4792.3.193.112/2992.3.193.113 to 92.3.193.11892.3.193.1196
4892.3.193.120/2992.3.193.121 to 92.3.193.12692.3.193.1276
4992.3.193.128/2992.3.193.129 to 92.3.193.13492.3.193.1356
5092.3.193.136/2992.3.193.137 to 92.3.193.14292.3.193.1436
5192.3.193.144/2992.3.193.145 to 92.3.193.15092.3.193.1516
5292.3.193.152/2992.3.193.153 to 92.3.193.15892.3.193.1596
5392.3.193.160/2992.3.193.161 to 92.3.193.16692.3.193.1676
5492.3.193.168/2992.3.193.169 to 92.3.193.17492.3.193.1756
5592.3.193.176/2992.3.193.177 to 92.3.193.18292.3.193.1836
5692.3.193.184/2992.3.193.185 to 92.3.193.19092.3.193.1916
5792.3.193.192/2992.3.193.193 to 92.3.193.19892.3.193.1996
5892.3.193.200/2992.3.193.201 to 92.3.193.20692.3.193.2076
5992.3.193.208/2992.3.193.209 to 92.3.193.21492.3.193.2156
6092.3.193.216/2992.3.193.217 to 92.3.193.22292.3.193.2236
6192.3.193.224/2992.3.193.225 to 92.3.193.23092.3.193.2316
6292.3.193.232/2992.3.193.233 to 92.3.193.23892.3.193.2396
6392.3.193.240/2992.3.193.241 to 92.3.193.24692.3.193.2476
6492.3.193.248/2992.3.193.249 to 92.3.193.25492.3.193.2556
6592.3.194.0/2992.3.194.1 to 92.3.194.692.3.194.76
6692.3.194.8/2992.3.194.9 to 92.3.194.1492.3.194.156
6792.3.194.16/2992.3.194.17 to 92.3.194.2292.3.194.236
6892.3.194.24/2992.3.194.25 to 92.3.194.3092.3.194.316
6992.3.194.32/2992.3.194.33 to 92.3.194.3892.3.194.396
7092.3.194.40/2992.3.194.41 to 92.3.194.4692.3.194.476
7192.3.194.48/2992.3.194.49 to 92.3.194.5492.3.194.556
7292.3.194.56/2992.3.194.57 to 92.3.194.6292.3.194.636
7392.3.194.64/2992.3.194.65 to 92.3.194.7092.3.194.716
7492.3.194.72/2992.3.194.73 to 92.3.194.7892.3.194.796
7592.3.194.80/2992.3.194.81 to 92.3.194.8692.3.194.876
7692.3.194.88/2992.3.194.89 to 92.3.194.9492.3.194.956
7792.3.194.96/2992.3.194.97 to 92.3.194.10292.3.194.1036
7892.3.194.104/2992.3.194.105 to 92.3.194.11092.3.194.1116
7992.3.194.112/2992.3.194.113 to 92.3.194.11892.3.194.1196
8092.3.194.120/2992.3.194.121 to 92.3.194.12692.3.194.1276
8192.3.194.128/2992.3.194.129 to 92.3.194.13492.3.194.1356
8292.3.194.136/2992.3.194.137 to 92.3.194.14292.3.194.1436
8392.3.194.144/2992.3.194.145 to 92.3.194.15092.3.194.1516
8492.3.194.152/2992.3.194.153 to 92.3.194.15892.3.194.1596
8592.3.194.160/2992.3.194.161 to 92.3.194.16692.3.194.1676
8692.3.194.168/2992.3.194.169 to 92.3.194.17492.3.194.1756
8792.3.194.176/2992.3.194.177 to 92.3.194.18292.3.194.1836
8892.3.194.184/2992.3.194.185 to 92.3.194.19092.3.194.1916
8992.3.194.192/2992.3.194.193 to 92.3.194.19892.3.194.1996
9092.3.194.200/2992.3.194.201 to 92.3.194.20692.3.194.2076
9192.3.194.208/2992.3.194.209 to 92.3.194.21492.3.194.2156
9292.3.194.216/2992.3.194.217 to 92.3.194.22292.3.194.2236
9392.3.194.224/2992.3.194.225 to 92.3.194.23092.3.194.2316
9492.3.194.232/2992.3.194.233 to 92.3.194.23892.3.194.2396
9592.3.194.240/2992.3.194.241 to 92.3.194.24692.3.194.2476
9692.3.194.248/2992.3.194.249 to 92.3.194.25492.3.194.2556
9792.3.195.0/2992.3.195.1 to 92.3.195.692.3.195.76
9892.3.195.8/2992.3.195.9 to 92.3.195.1492.3.195.156
9992.3.195.16/2992.3.195.17 to 92.3.195.2292.3.195.236
10092.3.195.24/2992.3.195.25 to 92.3.195.3092.3.195.316
10192.3.195.32/2992.3.195.33 to 92.3.195.3892.3.195.396
10292.3.195.40/2992.3.195.41 to 92.3.195.4692.3.195.476
10392.3.195.48/2992.3.195.49 to 92.3.195.5492.3.195.556
10492.3.195.56/2992.3.195.57 to 92.3.195.6292.3.195.636
10592.3.195.64/2992.3.195.65 to 92.3.195.7092.3.195.716
10692.3.195.72/2992.3.195.73 to 92.3.195.7892.3.195.796
10792.3.195.80/2992.3.195.81 to 92.3.195.8692.3.195.876
10892.3.195.88/2992.3.195.89 to 92.3.195.9492.3.195.956
10992.3.195.96/2992.3.195.97 to 92.3.195.10292.3.195.1036
11092.3.195.104/2992.3.195.105 to 92.3.195.11092.3.195.1116
11192.3.195.112/2992.3.195.113 to 92.3.195.11892.3.195.1196
11292.3.195.120/2992.3.195.121 to 92.3.195.12692.3.195.1276
11392.3.195.128/2992.3.195.129 to 92.3.195.13492.3.195.1356
11492.3.195.136/2992.3.195.137 to 92.3.195.14292.3.195.1436
11592.3.195.144/2992.3.195.145 to 92.3.195.15092.3.195.1516
11692.3.195.152/2992.3.195.153 to 92.3.195.15892.3.195.1596
11792.3.195.160/2992.3.195.161 to 92.3.195.16692.3.195.1676
11892.3.195.168/2992.3.195.169 to 92.3.195.17492.3.195.1756
11992.3.195.176/2992.3.195.177 to 92.3.195.18292.3.195.1836
12092.3.195.184/2992.3.195.185 to 92.3.195.19092.3.195.1916
12192.3.195.192/2992.3.195.193 to 92.3.195.19892.3.195.1996
12292.3.195.200/2992.3.195.201 to 92.3.195.20692.3.195.2076
12392.3.195.208/2992.3.195.209 to 92.3.195.21492.3.195.2156
12492.3.195.216/2992.3.195.217 to 92.3.195.22292.3.195.2236
12592.3.195.224/2992.3.195.225 to 92.3.195.23092.3.195.2316
12692.3.195.232/2992.3.195.233 to 92.3.195.23892.3.195.2396
12792.3.195.240/2992.3.195.241 to 92.3.195.24692.3.195.2476
12892.3.195.248/2992.3.195.249 to 92.3.195.25492.3.195.2556
12992.3.196.0/2992.3.196.1 to 92.3.196.692.3.196.76
13092.3.196.8/2992.3.196.9 to 92.3.196.1492.3.196.156
13192.3.196.16/2992.3.196.17 to 92.3.196.2292.3.196.236
13292.3.196.24/2992.3.196.25 to 92.3.196.3092.3.196.316
13392.3.196.32/2992.3.196.33 to 92.3.196.3892.3.196.396
13492.3.196.40/2992.3.196.41 to 92.3.196.4692.3.196.476
13592.3.196.48/2992.3.196.49 to 92.3.196.5492.3.196.556
13692.3.196.56/2992.3.196.57 to 92.3.196.6292.3.196.636
13792.3.196.64/2992.3.196.65 to 92.3.196.7092.3.196.716
13892.3.196.72/2992.3.196.73 to 92.3.196.7892.3.196.796
13992.3.196.80/2992.3.196.81 to 92.3.196.8692.3.196.876
14092.3.196.88/2992.3.196.89 to 92.3.196.9492.3.196.956
14192.3.196.96/2992.3.196.97 to 92.3.196.10292.3.196.1036
14292.3.196.104/2992.3.196.105 to 92.3.196.11092.3.196.1116
14392.3.196.112/2992.3.196.113 to 92.3.196.11892.3.196.1196
14492.3.196.120/2992.3.196.121 to 92.3.196.12692.3.196.1276
14592.3.196.128/2992.3.196.129 to 92.3.196.13492.3.196.1356
14692.3.196.136/2992.3.196.137 to 92.3.196.14292.3.196.1436
14792.3.196.144/2992.3.196.145 to 92.3.196.15092.3.196.1516
14892.3.196.152/2992.3.196.153 to 92.3.196.15892.3.196.1596
14992.3.196.160/2992.3.196.161 to 92.3.196.16692.3.196.1676
15092.3.196.168/2992.3.196.169 to 92.3.196.17492.3.196.1756
15192.3.196.176/2992.3.196.177 to 92.3.196.18292.3.196.1836
15292.3.196.184/2992.3.196.185 to 92.3.196.19092.3.196.1916
15392.3.196.192/2992.3.196.193 to 92.3.196.19892.3.196.1996
15492.3.196.200/2992.3.196.201 to 92.3.196.20692.3.196.2076
15592.3.196.208/2992.3.196.209 to 92.3.196.21492.3.196.2156
15692.3.196.216/2992.3.196.217 to 92.3.196.22292.3.196.2236
15792.3.196.224/2992.3.196.225 to 92.3.196.23092.3.196.2316
15892.3.196.232/2992.3.196.233 to 92.3.196.23892.3.196.2396
15992.3.196.240/2992.3.196.241 to 92.3.196.24692.3.196.2476
16092.3.196.248/2992.3.196.249 to 92.3.196.25492.3.196.2556
16192.3.197.0/2992.3.197.1 to 92.3.197.692.3.197.76
16292.3.197.8/2992.3.197.9 to 92.3.197.1492.3.197.156
16392.3.197.16/2992.3.197.17 to 92.3.197.2292.3.197.236
16492.3.197.24/2992.3.197.25 to 92.3.197.3092.3.197.316
16592.3.197.32/2992.3.197.33 to 92.3.197.3892.3.197.396
16692.3.197.40/2992.3.197.41 to 92.3.197.4692.3.197.476
16792.3.197.48/2992.3.197.49 to 92.3.197.5492.3.197.556
16892.3.197.56/2992.3.197.57 to 92.3.197.6292.3.197.636
16992.3.197.64/2992.3.197.65 to 92.3.197.7092.3.197.716
17092.3.197.72/2992.3.197.73 to 92.3.197.7892.3.197.796
17192.3.197.80/2992.3.197.81 to 92.3.197.8692.3.197.876
17292.3.197.88/2992.3.197.89 to 92.3.197.9492.3.197.956
17392.3.197.96/2992.3.197.97 to 92.3.197.10292.3.197.1036
17492.3.197.104/2992.3.197.105 to 92.3.197.11092.3.197.1116
17592.3.197.112/2992.3.197.113 to 92.3.197.11892.3.197.1196
17692.3.197.120/2992.3.197.121 to 92.3.197.12692.3.197.1276
17792.3.197.128/2992.3.197.129 to 92.3.197.13492.3.197.1356
17892.3.197.136/2992.3.197.137 to 92.3.197.14292.3.197.1436
17992.3.197.144/2992.3.197.145 to 92.3.197.15092.3.197.1516
18092.3.197.152/2992.3.197.153 to 92.3.197.15892.3.197.1596
18192.3.197.160/2992.3.197.161 to 92.3.197.16692.3.197.1676
18292.3.197.168/2992.3.197.169 to 92.3.197.17492.3.197.1756
18392.3.197.176/2992.3.197.177 to 92.3.197.18292.3.197.1836
18492.3.197.184/2992.3.197.185 to 92.3.197.19092.3.197.1916
18592.3.197.192/2992.3.197.193 to 92.3.197.19892.3.197.1996
18692.3.197.200/2992.3.197.201 to 92.3.197.20692.3.197.2076
18792.3.197.208/2992.3.197.209 to 92.3.197.21492.3.197.2156
18892.3.197.216/2992.3.197.217 to 92.3.197.22292.3.197.2236
18992.3.197.224/2992.3.197.225 to 92.3.197.23092.3.197.2316
19092.3.197.232/2992.3.197.233 to 92.3.197.23892.3.197.2396
19192.3.197.240/2992.3.197.241 to 92.3.197.24692.3.197.2476
19292.3.197.248/2992.3.197.249 to 92.3.197.25492.3.197.2556
19392.3.198.0/2992.3.198.1 to 92.3.198.692.3.198.76
19492.3.198.8/2992.3.198.9 to 92.3.198.1492.3.198.156
19592.3.198.16/2992.3.198.17 to 92.3.198.2292.3.198.236
19692.3.198.24/2992.3.198.25 to 92.3.198.3092.3.198.316
19792.3.198.32/2992.3.198.33 to 92.3.198.3892.3.198.396
19892.3.198.40/2992.3.198.41 to 92.3.198.4692.3.198.476
19992.3.198.48/2992.3.198.49 to 92.3.198.5492.3.198.556
20092.3.198.56/2992.3.198.57 to 92.3.198.6292.3.198.636
20192.3.198.64/2992.3.198.65 to 92.3.198.7092.3.198.716
20292.3.198.72/2992.3.198.73 to 92.3.198.7892.3.198.796
20392.3.198.80/2992.3.198.81 to 92.3.198.8692.3.198.876
20492.3.198.88/2992.3.198.89 to 92.3.198.9492.3.198.956
20592.3.198.96/2992.3.198.97 to 92.3.198.10292.3.198.1036
20692.3.198.104/2992.3.198.105 to 92.3.198.11092.3.198.1116
20792.3.198.112/2992.3.198.113 to 92.3.198.11892.3.198.1196
20892.3.198.120/2992.3.198.121 to 92.3.198.12692.3.198.1276
20992.3.198.128/2992.3.198.129 to 92.3.198.13492.3.198.1356
21092.3.198.136/2992.3.198.137 to 92.3.198.14292.3.198.1436
21192.3.198.144/2992.3.198.145 to 92.3.198.15092.3.198.1516
21292.3.198.152/2992.3.198.153 to 92.3.198.15892.3.198.1596
21392.3.198.160/2992.3.198.161 to 92.3.198.16692.3.198.1676
21492.3.198.168/2992.3.198.169 to 92.3.198.17492.3.198.1756
21592.3.198.176/2992.3.198.177 to 92.3.198.18292.3.198.1836
21692.3.198.184/2992.3.198.185 to 92.3.198.19092.3.198.1916
21792.3.198.192/2992.3.198.193 to 92.3.198.19892.3.198.1996
21892.3.198.200/2992.3.198.201 to 92.3.198.20692.3.198.2076
21992.3.198.208/2992.3.198.209 to 92.3.198.21492.3.198.2156
22092.3.198.216/2992.3.198.217 to 92.3.198.22292.3.198.2236
22192.3.198.224/2992.3.198.225 to 92.3.198.23092.3.198.2316
22292.3.198.232/2992.3.198.233 to 92.3.198.23892.3.198.2396
22392.3.198.240/2992.3.198.241 to 92.3.198.24692.3.198.2476
22492.3.198.248/2992.3.198.249 to 92.3.198.25492.3.198.2556
22592.3.199.0/2992.3.199.1 to 92.3.199.692.3.199.76
22692.3.199.8/2992.3.199.9 to 92.3.199.1492.3.199.156
22792.3.199.16/2992.3.199.17 to 92.3.199.2292.3.199.236
22892.3.199.24/2992.3.199.25 to 92.3.199.3092.3.199.316
22992.3.199.32/2992.3.199.33 to 92.3.199.3892.3.199.396
23092.3.199.40/2992.3.199.41 to 92.3.199.4692.3.199.476
23192.3.199.48/2992.3.199.49 to 92.3.199.5492.3.199.556
23292.3.199.56/2992.3.199.57 to 92.3.199.6292.3.199.636
23392.3.199.64/2992.3.199.65 to 92.3.199.7092.3.199.716
23492.3.199.72/2992.3.199.73 to 92.3.199.7892.3.199.796
23592.3.199.80/2992.3.199.81 to 92.3.199.8692.3.199.876
23692.3.199.88/2992.3.199.89 to 92.3.199.9492.3.199.956
23792.3.199.96/2992.3.199.97 to 92.3.199.10292.3.199.1036
23892.3.199.104/2992.3.199.105 to 92.3.199.11092.3.199.1116
23992.3.199.112/2992.3.199.113 to 92.3.199.11892.3.199.1196
24092.3.199.120/2992.3.199.121 to 92.3.199.12692.3.199.1276
24192.3.199.128/2992.3.199.129 to 92.3.199.13492.3.199.1356
24292.3.199.136/2992.3.199.137 to 92.3.199.14292.3.199.1436
24392.3.199.144/2992.3.199.145 to 92.3.199.15092.3.199.1516
24492.3.199.152/2992.3.199.153 to 92.3.199.15892.3.199.1596
24592.3.199.160/2992.3.199.161 to 92.3.199.16692.3.199.1676
24692.3.199.168/2992.3.199.169 to 92.3.199.17492.3.199.1756
24792.3.199.176/2992.3.199.177 to 92.3.199.18292.3.199.1836
24892.3.199.184/2992.3.199.185 to 92.3.199.19092.3.199.1916
24992.3.199.192/2992.3.199.193 to 92.3.199.19892.3.199.1996
25092.3.199.200/2992.3.199.201 to 92.3.199.20692.3.199.2076
25192.3.199.208/2992.3.199.209 to 92.3.199.21492.3.199.2156
25292.3.199.216/2992.3.199.217 to 92.3.199.22292.3.199.2236
25392.3.199.224/2992.3.199.225 to 92.3.199.23092.3.199.2316
25492.3.199.232/2992.3.199.233 to 92.3.199.23892.3.199.2396
25592.3.199.240/2992.3.199.241 to 92.3.199.24692.3.199.2476
25692.3.199.248/2992.3.199.249 to 92.3.199.25492.3.199.2556

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.