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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.

Network49.49.0.0/16
Usable hosts65,534
Subnet mask255.255.0.0
Addresses65,536
Network address
49.49.0.0
Broadcast address
49.49.255.255
First usable
49.49.0.1
Last usable
49.49.255.254
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 31310000 · Integer 825294848 to 825360383
Reverse DNS zone
49.49.in-addr.arpa
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address00110001.00110001..00000000.0000000049.49.0.0
Subnet mask11111111.11111111..00000000.00000000255.255.0.0
Network00110001.00110001..00000000.0000000049.49.0.0
Broadcast00110001.00110001..11111111.1111111149.49.255.255
Split into smaller subnets/25
/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)

49.49.0.0/16 makes 512 subnets of /25; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
149.49.0.0/2549.49.0.1 to 49.49.0.12649.49.0.127126
249.49.0.128/2549.49.0.129 to 49.49.0.25449.49.0.255126
349.49.1.0/2549.49.1.1 to 49.49.1.12649.49.1.127126
449.49.1.128/2549.49.1.129 to 49.49.1.25449.49.1.255126
549.49.2.0/2549.49.2.1 to 49.49.2.12649.49.2.127126
649.49.2.128/2549.49.2.129 to 49.49.2.25449.49.2.255126
749.49.3.0/2549.49.3.1 to 49.49.3.12649.49.3.127126
849.49.3.128/2549.49.3.129 to 49.49.3.25449.49.3.255126
949.49.4.0/2549.49.4.1 to 49.49.4.12649.49.4.127126
1049.49.4.128/2549.49.4.129 to 49.49.4.25449.49.4.255126
1149.49.5.0/2549.49.5.1 to 49.49.5.12649.49.5.127126
1249.49.5.128/2549.49.5.129 to 49.49.5.25449.49.5.255126
1349.49.6.0/2549.49.6.1 to 49.49.6.12649.49.6.127126
1449.49.6.128/2549.49.6.129 to 49.49.6.25449.49.6.255126
1549.49.7.0/2549.49.7.1 to 49.49.7.12649.49.7.127126
1649.49.7.128/2549.49.7.129 to 49.49.7.25449.49.7.255126
1749.49.8.0/2549.49.8.1 to 49.49.8.12649.49.8.127126
1849.49.8.128/2549.49.8.129 to 49.49.8.25449.49.8.255126
1949.49.9.0/2549.49.9.1 to 49.49.9.12649.49.9.127126
2049.49.9.128/2549.49.9.129 to 49.49.9.25449.49.9.255126
2149.49.10.0/2549.49.10.1 to 49.49.10.12649.49.10.127126
2249.49.10.128/2549.49.10.129 to 49.49.10.25449.49.10.255126
2349.49.11.0/2549.49.11.1 to 49.49.11.12649.49.11.127126
2449.49.11.128/2549.49.11.129 to 49.49.11.25449.49.11.255126
2549.49.12.0/2549.49.12.1 to 49.49.12.12649.49.12.127126
2649.49.12.128/2549.49.12.129 to 49.49.12.25449.49.12.255126
2749.49.13.0/2549.49.13.1 to 49.49.13.12649.49.13.127126
2849.49.13.128/2549.49.13.129 to 49.49.13.25449.49.13.255126
2949.49.14.0/2549.49.14.1 to 49.49.14.12649.49.14.127126
3049.49.14.128/2549.49.14.129 to 49.49.14.25449.49.14.255126
3149.49.15.0/2549.49.15.1 to 49.49.15.12649.49.15.127126
3249.49.15.128/2549.49.15.129 to 49.49.15.25449.49.15.255126
3349.49.16.0/2549.49.16.1 to 49.49.16.12649.49.16.127126
3449.49.16.128/2549.49.16.129 to 49.49.16.25449.49.16.255126
3549.49.17.0/2549.49.17.1 to 49.49.17.12649.49.17.127126
3649.49.17.128/2549.49.17.129 to 49.49.17.25449.49.17.255126
3749.49.18.0/2549.49.18.1 to 49.49.18.12649.49.18.127126
3849.49.18.128/2549.49.18.129 to 49.49.18.25449.49.18.255126
3949.49.19.0/2549.49.19.1 to 49.49.19.12649.49.19.127126
4049.49.19.128/2549.49.19.129 to 49.49.19.25449.49.19.255126
4149.49.20.0/2549.49.20.1 to 49.49.20.12649.49.20.127126
4249.49.20.128/2549.49.20.129 to 49.49.20.25449.49.20.255126
4349.49.21.0/2549.49.21.1 to 49.49.21.12649.49.21.127126
4449.49.21.128/2549.49.21.129 to 49.49.21.25449.49.21.255126
4549.49.22.0/2549.49.22.1 to 49.49.22.12649.49.22.127126
4649.49.22.128/2549.49.22.129 to 49.49.22.25449.49.22.255126
4749.49.23.0/2549.49.23.1 to 49.49.23.12649.49.23.127126
4849.49.23.128/2549.49.23.129 to 49.49.23.25449.49.23.255126
4949.49.24.0/2549.49.24.1 to 49.49.24.12649.49.24.127126
5049.49.24.128/2549.49.24.129 to 49.49.24.25449.49.24.255126
5149.49.25.0/2549.49.25.1 to 49.49.25.12649.49.25.127126
5249.49.25.128/2549.49.25.129 to 49.49.25.25449.49.25.255126
5349.49.26.0/2549.49.26.1 to 49.49.26.12649.49.26.127126
5449.49.26.128/2549.49.26.129 to 49.49.26.25449.49.26.255126
5549.49.27.0/2549.49.27.1 to 49.49.27.12649.49.27.127126
5649.49.27.128/2549.49.27.129 to 49.49.27.25449.49.27.255126
5749.49.28.0/2549.49.28.1 to 49.49.28.12649.49.28.127126
5849.49.28.128/2549.49.28.129 to 49.49.28.25449.49.28.255126
5949.49.29.0/2549.49.29.1 to 49.49.29.12649.49.29.127126
6049.49.29.128/2549.49.29.129 to 49.49.29.25449.49.29.255126
6149.49.30.0/2549.49.30.1 to 49.49.30.12649.49.30.127126
6249.49.30.128/2549.49.30.129 to 49.49.30.25449.49.30.255126
6349.49.31.0/2549.49.31.1 to 49.49.31.12649.49.31.127126
6449.49.31.128/2549.49.31.129 to 49.49.31.25449.49.31.255126
6549.49.32.0/2549.49.32.1 to 49.49.32.12649.49.32.127126
6649.49.32.128/2549.49.32.129 to 49.49.32.25449.49.32.255126
6749.49.33.0/2549.49.33.1 to 49.49.33.12649.49.33.127126
6849.49.33.128/2549.49.33.129 to 49.49.33.25449.49.33.255126
6949.49.34.0/2549.49.34.1 to 49.49.34.12649.49.34.127126
7049.49.34.128/2549.49.34.129 to 49.49.34.25449.49.34.255126
7149.49.35.0/2549.49.35.1 to 49.49.35.12649.49.35.127126
7249.49.35.128/2549.49.35.129 to 49.49.35.25449.49.35.255126
7349.49.36.0/2549.49.36.1 to 49.49.36.12649.49.36.127126
7449.49.36.128/2549.49.36.129 to 49.49.36.25449.49.36.255126
7549.49.37.0/2549.49.37.1 to 49.49.37.12649.49.37.127126
7649.49.37.128/2549.49.37.129 to 49.49.37.25449.49.37.255126
7749.49.38.0/2549.49.38.1 to 49.49.38.12649.49.38.127126
7849.49.38.128/2549.49.38.129 to 49.49.38.25449.49.38.255126
7949.49.39.0/2549.49.39.1 to 49.49.39.12649.49.39.127126
8049.49.39.128/2549.49.39.129 to 49.49.39.25449.49.39.255126
8149.49.40.0/2549.49.40.1 to 49.49.40.12649.49.40.127126
8249.49.40.128/2549.49.40.129 to 49.49.40.25449.49.40.255126
8349.49.41.0/2549.49.41.1 to 49.49.41.12649.49.41.127126
8449.49.41.128/2549.49.41.129 to 49.49.41.25449.49.41.255126
8549.49.42.0/2549.49.42.1 to 49.49.42.12649.49.42.127126
8649.49.42.128/2549.49.42.129 to 49.49.42.25449.49.42.255126
8749.49.43.0/2549.49.43.1 to 49.49.43.12649.49.43.127126
8849.49.43.128/2549.49.43.129 to 49.49.43.25449.49.43.255126
8949.49.44.0/2549.49.44.1 to 49.49.44.12649.49.44.127126
9049.49.44.128/2549.49.44.129 to 49.49.44.25449.49.44.255126
9149.49.45.0/2549.49.45.1 to 49.49.45.12649.49.45.127126
9249.49.45.128/2549.49.45.129 to 49.49.45.25449.49.45.255126
9349.49.46.0/2549.49.46.1 to 49.49.46.12649.49.46.127126
9449.49.46.128/2549.49.46.129 to 49.49.46.25449.49.46.255126
9549.49.47.0/2549.49.47.1 to 49.49.47.12649.49.47.127126
9649.49.47.128/2549.49.47.129 to 49.49.47.25449.49.47.255126
9749.49.48.0/2549.49.48.1 to 49.49.48.12649.49.48.127126
9849.49.48.128/2549.49.48.129 to 49.49.48.25449.49.48.255126
9949.49.49.0/2549.49.49.1 to 49.49.49.12649.49.49.127126
10049.49.49.128/2549.49.49.129 to 49.49.49.25449.49.49.255126
10149.49.50.0/2549.49.50.1 to 49.49.50.12649.49.50.127126
10249.49.50.128/2549.49.50.129 to 49.49.50.25449.49.50.255126
10349.49.51.0/2549.49.51.1 to 49.49.51.12649.49.51.127126
10449.49.51.128/2549.49.51.129 to 49.49.51.25449.49.51.255126
10549.49.52.0/2549.49.52.1 to 49.49.52.12649.49.52.127126
10649.49.52.128/2549.49.52.129 to 49.49.52.25449.49.52.255126
10749.49.53.0/2549.49.53.1 to 49.49.53.12649.49.53.127126
10849.49.53.128/2549.49.53.129 to 49.49.53.25449.49.53.255126
10949.49.54.0/2549.49.54.1 to 49.49.54.12649.49.54.127126
11049.49.54.128/2549.49.54.129 to 49.49.54.25449.49.54.255126
11149.49.55.0/2549.49.55.1 to 49.49.55.12649.49.55.127126
11249.49.55.128/2549.49.55.129 to 49.49.55.25449.49.55.255126
11349.49.56.0/2549.49.56.1 to 49.49.56.12649.49.56.127126
11449.49.56.128/2549.49.56.129 to 49.49.56.25449.49.56.255126
11549.49.57.0/2549.49.57.1 to 49.49.57.12649.49.57.127126
11649.49.57.128/2549.49.57.129 to 49.49.57.25449.49.57.255126
11749.49.58.0/2549.49.58.1 to 49.49.58.12649.49.58.127126
11849.49.58.128/2549.49.58.129 to 49.49.58.25449.49.58.255126
11949.49.59.0/2549.49.59.1 to 49.49.59.12649.49.59.127126
12049.49.59.128/2549.49.59.129 to 49.49.59.25449.49.59.255126
12149.49.60.0/2549.49.60.1 to 49.49.60.12649.49.60.127126
12249.49.60.128/2549.49.60.129 to 49.49.60.25449.49.60.255126
12349.49.61.0/2549.49.61.1 to 49.49.61.12649.49.61.127126
12449.49.61.128/2549.49.61.129 to 49.49.61.25449.49.61.255126
12549.49.62.0/2549.49.62.1 to 49.49.62.12649.49.62.127126
12649.49.62.128/2549.49.62.129 to 49.49.62.25449.49.62.255126
12749.49.63.0/2549.49.63.1 to 49.49.63.12649.49.63.127126
12849.49.63.128/2549.49.63.129 to 49.49.63.25449.49.63.255126
12949.49.64.0/2549.49.64.1 to 49.49.64.12649.49.64.127126
13049.49.64.128/2549.49.64.129 to 49.49.64.25449.49.64.255126
13149.49.65.0/2549.49.65.1 to 49.49.65.12649.49.65.127126
13249.49.65.128/2549.49.65.129 to 49.49.65.25449.49.65.255126
13349.49.66.0/2549.49.66.1 to 49.49.66.12649.49.66.127126
13449.49.66.128/2549.49.66.129 to 49.49.66.25449.49.66.255126
13549.49.67.0/2549.49.67.1 to 49.49.67.12649.49.67.127126
13649.49.67.128/2549.49.67.129 to 49.49.67.25449.49.67.255126
13749.49.68.0/2549.49.68.1 to 49.49.68.12649.49.68.127126
13849.49.68.128/2549.49.68.129 to 49.49.68.25449.49.68.255126
13949.49.69.0/2549.49.69.1 to 49.49.69.12649.49.69.127126
14049.49.69.128/2549.49.69.129 to 49.49.69.25449.49.69.255126
14149.49.70.0/2549.49.70.1 to 49.49.70.12649.49.70.127126
14249.49.70.128/2549.49.70.129 to 49.49.70.25449.49.70.255126
14349.49.71.0/2549.49.71.1 to 49.49.71.12649.49.71.127126
14449.49.71.128/2549.49.71.129 to 49.49.71.25449.49.71.255126
14549.49.72.0/2549.49.72.1 to 49.49.72.12649.49.72.127126
14649.49.72.128/2549.49.72.129 to 49.49.72.25449.49.72.255126
14749.49.73.0/2549.49.73.1 to 49.49.73.12649.49.73.127126
14849.49.73.128/2549.49.73.129 to 49.49.73.25449.49.73.255126
14949.49.74.0/2549.49.74.1 to 49.49.74.12649.49.74.127126
15049.49.74.128/2549.49.74.129 to 49.49.74.25449.49.74.255126
15149.49.75.0/2549.49.75.1 to 49.49.75.12649.49.75.127126
15249.49.75.128/2549.49.75.129 to 49.49.75.25449.49.75.255126
15349.49.76.0/2549.49.76.1 to 49.49.76.12649.49.76.127126
15449.49.76.128/2549.49.76.129 to 49.49.76.25449.49.76.255126
15549.49.77.0/2549.49.77.1 to 49.49.77.12649.49.77.127126
15649.49.77.128/2549.49.77.129 to 49.49.77.25449.49.77.255126
15749.49.78.0/2549.49.78.1 to 49.49.78.12649.49.78.127126
15849.49.78.128/2549.49.78.129 to 49.49.78.25449.49.78.255126
15949.49.79.0/2549.49.79.1 to 49.49.79.12649.49.79.127126
16049.49.79.128/2549.49.79.129 to 49.49.79.25449.49.79.255126
16149.49.80.0/2549.49.80.1 to 49.49.80.12649.49.80.127126
16249.49.80.128/2549.49.80.129 to 49.49.80.25449.49.80.255126
16349.49.81.0/2549.49.81.1 to 49.49.81.12649.49.81.127126
16449.49.81.128/2549.49.81.129 to 49.49.81.25449.49.81.255126
16549.49.82.0/2549.49.82.1 to 49.49.82.12649.49.82.127126
16649.49.82.128/2549.49.82.129 to 49.49.82.25449.49.82.255126
16749.49.83.0/2549.49.83.1 to 49.49.83.12649.49.83.127126
16849.49.83.128/2549.49.83.129 to 49.49.83.25449.49.83.255126
16949.49.84.0/2549.49.84.1 to 49.49.84.12649.49.84.127126
17049.49.84.128/2549.49.84.129 to 49.49.84.25449.49.84.255126
17149.49.85.0/2549.49.85.1 to 49.49.85.12649.49.85.127126
17249.49.85.128/2549.49.85.129 to 49.49.85.25449.49.85.255126
17349.49.86.0/2549.49.86.1 to 49.49.86.12649.49.86.127126
17449.49.86.128/2549.49.86.129 to 49.49.86.25449.49.86.255126
17549.49.87.0/2549.49.87.1 to 49.49.87.12649.49.87.127126
17649.49.87.128/2549.49.87.129 to 49.49.87.25449.49.87.255126
17749.49.88.0/2549.49.88.1 to 49.49.88.12649.49.88.127126
17849.49.88.128/2549.49.88.129 to 49.49.88.25449.49.88.255126
17949.49.89.0/2549.49.89.1 to 49.49.89.12649.49.89.127126
18049.49.89.128/2549.49.89.129 to 49.49.89.25449.49.89.255126
18149.49.90.0/2549.49.90.1 to 49.49.90.12649.49.90.127126
18249.49.90.128/2549.49.90.129 to 49.49.90.25449.49.90.255126
18349.49.91.0/2549.49.91.1 to 49.49.91.12649.49.91.127126
18449.49.91.128/2549.49.91.129 to 49.49.91.25449.49.91.255126
18549.49.92.0/2549.49.92.1 to 49.49.92.12649.49.92.127126
18649.49.92.128/2549.49.92.129 to 49.49.92.25449.49.92.255126
18749.49.93.0/2549.49.93.1 to 49.49.93.12649.49.93.127126
18849.49.93.128/2549.49.93.129 to 49.49.93.25449.49.93.255126
18949.49.94.0/2549.49.94.1 to 49.49.94.12649.49.94.127126
19049.49.94.128/2549.49.94.129 to 49.49.94.25449.49.94.255126
19149.49.95.0/2549.49.95.1 to 49.49.95.12649.49.95.127126
19249.49.95.128/2549.49.95.129 to 49.49.95.25449.49.95.255126
19349.49.96.0/2549.49.96.1 to 49.49.96.12649.49.96.127126
19449.49.96.128/2549.49.96.129 to 49.49.96.25449.49.96.255126
19549.49.97.0/2549.49.97.1 to 49.49.97.12649.49.97.127126
19649.49.97.128/2549.49.97.129 to 49.49.97.25449.49.97.255126
19749.49.98.0/2549.49.98.1 to 49.49.98.12649.49.98.127126
19849.49.98.128/2549.49.98.129 to 49.49.98.25449.49.98.255126
19949.49.99.0/2549.49.99.1 to 49.49.99.12649.49.99.127126
20049.49.99.128/2549.49.99.129 to 49.49.99.25449.49.99.255126
20149.49.100.0/2549.49.100.1 to 49.49.100.12649.49.100.127126
20249.49.100.128/2549.49.100.129 to 49.49.100.25449.49.100.255126
20349.49.101.0/2549.49.101.1 to 49.49.101.12649.49.101.127126
20449.49.101.128/2549.49.101.129 to 49.49.101.25449.49.101.255126
20549.49.102.0/2549.49.102.1 to 49.49.102.12649.49.102.127126
20649.49.102.128/2549.49.102.129 to 49.49.102.25449.49.102.255126
20749.49.103.0/2549.49.103.1 to 49.49.103.12649.49.103.127126
20849.49.103.128/2549.49.103.129 to 49.49.103.25449.49.103.255126
20949.49.104.0/2549.49.104.1 to 49.49.104.12649.49.104.127126
21049.49.104.128/2549.49.104.129 to 49.49.104.25449.49.104.255126
21149.49.105.0/2549.49.105.1 to 49.49.105.12649.49.105.127126
21249.49.105.128/2549.49.105.129 to 49.49.105.25449.49.105.255126
21349.49.106.0/2549.49.106.1 to 49.49.106.12649.49.106.127126
21449.49.106.128/2549.49.106.129 to 49.49.106.25449.49.106.255126
21549.49.107.0/2549.49.107.1 to 49.49.107.12649.49.107.127126
21649.49.107.128/2549.49.107.129 to 49.49.107.25449.49.107.255126
21749.49.108.0/2549.49.108.1 to 49.49.108.12649.49.108.127126
21849.49.108.128/2549.49.108.129 to 49.49.108.25449.49.108.255126
21949.49.109.0/2549.49.109.1 to 49.49.109.12649.49.109.127126
22049.49.109.128/2549.49.109.129 to 49.49.109.25449.49.109.255126
22149.49.110.0/2549.49.110.1 to 49.49.110.12649.49.110.127126
22249.49.110.128/2549.49.110.129 to 49.49.110.25449.49.110.255126
22349.49.111.0/2549.49.111.1 to 49.49.111.12649.49.111.127126
22449.49.111.128/2549.49.111.129 to 49.49.111.25449.49.111.255126
22549.49.112.0/2549.49.112.1 to 49.49.112.12649.49.112.127126
22649.49.112.128/2549.49.112.129 to 49.49.112.25449.49.112.255126
22749.49.113.0/2549.49.113.1 to 49.49.113.12649.49.113.127126
22849.49.113.128/2549.49.113.129 to 49.49.113.25449.49.113.255126
22949.49.114.0/2549.49.114.1 to 49.49.114.12649.49.114.127126
23049.49.114.128/2549.49.114.129 to 49.49.114.25449.49.114.255126
23149.49.115.0/2549.49.115.1 to 49.49.115.12649.49.115.127126
23249.49.115.128/2549.49.115.129 to 49.49.115.25449.49.115.255126
23349.49.116.0/2549.49.116.1 to 49.49.116.12649.49.116.127126
23449.49.116.128/2549.49.116.129 to 49.49.116.25449.49.116.255126
23549.49.117.0/2549.49.117.1 to 49.49.117.12649.49.117.127126
23649.49.117.128/2549.49.117.129 to 49.49.117.25449.49.117.255126
23749.49.118.0/2549.49.118.1 to 49.49.118.12649.49.118.127126
23849.49.118.128/2549.49.118.129 to 49.49.118.25449.49.118.255126
23949.49.119.0/2549.49.119.1 to 49.49.119.12649.49.119.127126
24049.49.119.128/2549.49.119.129 to 49.49.119.25449.49.119.255126
24149.49.120.0/2549.49.120.1 to 49.49.120.12649.49.120.127126
24249.49.120.128/2549.49.120.129 to 49.49.120.25449.49.120.255126
24349.49.121.0/2549.49.121.1 to 49.49.121.12649.49.121.127126
24449.49.121.128/2549.49.121.129 to 49.49.121.25449.49.121.255126
24549.49.122.0/2549.49.122.1 to 49.49.122.12649.49.122.127126
24649.49.122.128/2549.49.122.129 to 49.49.122.25449.49.122.255126
24749.49.123.0/2549.49.123.1 to 49.49.123.12649.49.123.127126
24849.49.123.128/2549.49.123.129 to 49.49.123.25449.49.123.255126
24949.49.124.0/2549.49.124.1 to 49.49.124.12649.49.124.127126
25049.49.124.128/2549.49.124.129 to 49.49.124.25449.49.124.255126
25149.49.125.0/2549.49.125.1 to 49.49.125.12649.49.125.127126
25249.49.125.128/2549.49.125.129 to 49.49.125.25449.49.125.255126
25349.49.126.0/2549.49.126.1 to 49.49.126.12649.49.126.127126
25449.49.126.128/2549.49.126.129 to 49.49.126.25449.49.126.255126
25549.49.127.0/2549.49.127.1 to 49.49.127.12649.49.127.127126
25649.49.127.128/2549.49.127.129 to 49.49.127.25449.49.127.255126

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.