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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.

Network49.0.0.0/9
Usable hosts8,388,606
Subnet mask255.128.0.0
Addresses8,388,608
Network address
49.0.0.0
Broadcast address
49.127.255.255
First usable
49.0.0.1
Last usable
49.127.255.254
Usable hosts
8,388,606 (8,388,608 less the network and broadcast addresses)
Subnet mask
255.128.0.0
Wildcard mask
0.127.255.255 (Cisco ACLs, OSPF)
Prefix length
/9
Type
Public public
Old class
A (default /8)
As numbers
Hex 31000000 · Integer 822083584 to 830472191
Reverse DNS zones
0.49.in-addr.arpa
1.49.in-addr.arpa
2.49.in-addr.arpa
3.49.in-addr.arpa
4.49.in-addr.arpa
5.49.in-addr.arpa
6.49.in-addr.arpa
7.49.in-addr.arpa
8.49.in-addr.arpa
9.49.in-addr.arpa
10.49.in-addr.arpa
11.49.in-addr.arpa
12.49.in-addr.arpa
13.49.in-addr.arpa
14.49.in-addr.arpa
15.49.in-addr.arpa
and 112 more
/9 is not on a 8-bit boundary, so it takes 128 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address00110001.00000000.00000000.0000000049.0.0.0
Subnet mask11111111.10000000.00000000.00000000255.128.0.0
Network00110001.00000000.00000000.0000000049.0.0.0
Broadcast00110001.01111111.11111111.1111111149.127.255.255
Split into smaller subnets/17
/10 (2)/11 (4)/12 (8)/13 (16)/14 (32)/15 (64)/16 (128)/17 (256)/18 (512)/19 (1,024)/20 (2,048)/21 (4,096)

49.0.0.0/9 makes 256 subnets of /17.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
149.0.0.0/1749.0.0.1 to 49.0.127.25449.0.127.25532,766
249.0.128.0/1749.0.128.1 to 49.0.255.25449.0.255.25532,766
349.1.0.0/1749.1.0.1 to 49.1.127.25449.1.127.25532,766
449.1.128.0/1749.1.128.1 to 49.1.255.25449.1.255.25532,766
549.2.0.0/1749.2.0.1 to 49.2.127.25449.2.127.25532,766
649.2.128.0/1749.2.128.1 to 49.2.255.25449.2.255.25532,766
749.3.0.0/1749.3.0.1 to 49.3.127.25449.3.127.25532,766
849.3.128.0/1749.3.128.1 to 49.3.255.25449.3.255.25532,766
949.4.0.0/1749.4.0.1 to 49.4.127.25449.4.127.25532,766
1049.4.128.0/1749.4.128.1 to 49.4.255.25449.4.255.25532,766
1149.5.0.0/1749.5.0.1 to 49.5.127.25449.5.127.25532,766
1249.5.128.0/1749.5.128.1 to 49.5.255.25449.5.255.25532,766
1349.6.0.0/1749.6.0.1 to 49.6.127.25449.6.127.25532,766
1449.6.128.0/1749.6.128.1 to 49.6.255.25449.6.255.25532,766
1549.7.0.0/1749.7.0.1 to 49.7.127.25449.7.127.25532,766
1649.7.128.0/1749.7.128.1 to 49.7.255.25449.7.255.25532,766
1749.8.0.0/1749.8.0.1 to 49.8.127.25449.8.127.25532,766
1849.8.128.0/1749.8.128.1 to 49.8.255.25449.8.255.25532,766
1949.9.0.0/1749.9.0.1 to 49.9.127.25449.9.127.25532,766
2049.9.128.0/1749.9.128.1 to 49.9.255.25449.9.255.25532,766
2149.10.0.0/1749.10.0.1 to 49.10.127.25449.10.127.25532,766
2249.10.128.0/1749.10.128.1 to 49.10.255.25449.10.255.25532,766
2349.11.0.0/1749.11.0.1 to 49.11.127.25449.11.127.25532,766
2449.11.128.0/1749.11.128.1 to 49.11.255.25449.11.255.25532,766
2549.12.0.0/1749.12.0.1 to 49.12.127.25449.12.127.25532,766
2649.12.128.0/1749.12.128.1 to 49.12.255.25449.12.255.25532,766
2749.13.0.0/1749.13.0.1 to 49.13.127.25449.13.127.25532,766
2849.13.128.0/1749.13.128.1 to 49.13.255.25449.13.255.25532,766
2949.14.0.0/1749.14.0.1 to 49.14.127.25449.14.127.25532,766
3049.14.128.0/1749.14.128.1 to 49.14.255.25449.14.255.25532,766
3149.15.0.0/1749.15.0.1 to 49.15.127.25449.15.127.25532,766
3249.15.128.0/1749.15.128.1 to 49.15.255.25449.15.255.25532,766
3349.16.0.0/1749.16.0.1 to 49.16.127.25449.16.127.25532,766
3449.16.128.0/1749.16.128.1 to 49.16.255.25449.16.255.25532,766
3549.17.0.0/1749.17.0.1 to 49.17.127.25449.17.127.25532,766
3649.17.128.0/1749.17.128.1 to 49.17.255.25449.17.255.25532,766
3749.18.0.0/1749.18.0.1 to 49.18.127.25449.18.127.25532,766
3849.18.128.0/1749.18.128.1 to 49.18.255.25449.18.255.25532,766
3949.19.0.0/1749.19.0.1 to 49.19.127.25449.19.127.25532,766
4049.19.128.0/1749.19.128.1 to 49.19.255.25449.19.255.25532,766
4149.20.0.0/1749.20.0.1 to 49.20.127.25449.20.127.25532,766
4249.20.128.0/1749.20.128.1 to 49.20.255.25449.20.255.25532,766
4349.21.0.0/1749.21.0.1 to 49.21.127.25449.21.127.25532,766
4449.21.128.0/1749.21.128.1 to 49.21.255.25449.21.255.25532,766
4549.22.0.0/1749.22.0.1 to 49.22.127.25449.22.127.25532,766
4649.22.128.0/1749.22.128.1 to 49.22.255.25449.22.255.25532,766
4749.23.0.0/1749.23.0.1 to 49.23.127.25449.23.127.25532,766
4849.23.128.0/1749.23.128.1 to 49.23.255.25449.23.255.25532,766
4949.24.0.0/1749.24.0.1 to 49.24.127.25449.24.127.25532,766
5049.24.128.0/1749.24.128.1 to 49.24.255.25449.24.255.25532,766
5149.25.0.0/1749.25.0.1 to 49.25.127.25449.25.127.25532,766
5249.25.128.0/1749.25.128.1 to 49.25.255.25449.25.255.25532,766
5349.26.0.0/1749.26.0.1 to 49.26.127.25449.26.127.25532,766
5449.26.128.0/1749.26.128.1 to 49.26.255.25449.26.255.25532,766
5549.27.0.0/1749.27.0.1 to 49.27.127.25449.27.127.25532,766
5649.27.128.0/1749.27.128.1 to 49.27.255.25449.27.255.25532,766
5749.28.0.0/1749.28.0.1 to 49.28.127.25449.28.127.25532,766
5849.28.128.0/1749.28.128.1 to 49.28.255.25449.28.255.25532,766
5949.29.0.0/1749.29.0.1 to 49.29.127.25449.29.127.25532,766
6049.29.128.0/1749.29.128.1 to 49.29.255.25449.29.255.25532,766
6149.30.0.0/1749.30.0.1 to 49.30.127.25449.30.127.25532,766
6249.30.128.0/1749.30.128.1 to 49.30.255.25449.30.255.25532,766
6349.31.0.0/1749.31.0.1 to 49.31.127.25449.31.127.25532,766
6449.31.128.0/1749.31.128.1 to 49.31.255.25449.31.255.25532,766
6549.32.0.0/1749.32.0.1 to 49.32.127.25449.32.127.25532,766
6649.32.128.0/1749.32.128.1 to 49.32.255.25449.32.255.25532,766
6749.33.0.0/1749.33.0.1 to 49.33.127.25449.33.127.25532,766
6849.33.128.0/1749.33.128.1 to 49.33.255.25449.33.255.25532,766
6949.34.0.0/1749.34.0.1 to 49.34.127.25449.34.127.25532,766
7049.34.128.0/1749.34.128.1 to 49.34.255.25449.34.255.25532,766
7149.35.0.0/1749.35.0.1 to 49.35.127.25449.35.127.25532,766
7249.35.128.0/1749.35.128.1 to 49.35.255.25449.35.255.25532,766
7349.36.0.0/1749.36.0.1 to 49.36.127.25449.36.127.25532,766
7449.36.128.0/1749.36.128.1 to 49.36.255.25449.36.255.25532,766
7549.37.0.0/1749.37.0.1 to 49.37.127.25449.37.127.25532,766
7649.37.128.0/1749.37.128.1 to 49.37.255.25449.37.255.25532,766
7749.38.0.0/1749.38.0.1 to 49.38.127.25449.38.127.25532,766
7849.38.128.0/1749.38.128.1 to 49.38.255.25449.38.255.25532,766
7949.39.0.0/1749.39.0.1 to 49.39.127.25449.39.127.25532,766
8049.39.128.0/1749.39.128.1 to 49.39.255.25449.39.255.25532,766
8149.40.0.0/1749.40.0.1 to 49.40.127.25449.40.127.25532,766
8249.40.128.0/1749.40.128.1 to 49.40.255.25449.40.255.25532,766
8349.41.0.0/1749.41.0.1 to 49.41.127.25449.41.127.25532,766
8449.41.128.0/1749.41.128.1 to 49.41.255.25449.41.255.25532,766
8549.42.0.0/1749.42.0.1 to 49.42.127.25449.42.127.25532,766
8649.42.128.0/1749.42.128.1 to 49.42.255.25449.42.255.25532,766
8749.43.0.0/1749.43.0.1 to 49.43.127.25449.43.127.25532,766
8849.43.128.0/1749.43.128.1 to 49.43.255.25449.43.255.25532,766
8949.44.0.0/1749.44.0.1 to 49.44.127.25449.44.127.25532,766
9049.44.128.0/1749.44.128.1 to 49.44.255.25449.44.255.25532,766
9149.45.0.0/1749.45.0.1 to 49.45.127.25449.45.127.25532,766
9249.45.128.0/1749.45.128.1 to 49.45.255.25449.45.255.25532,766
9349.46.0.0/1749.46.0.1 to 49.46.127.25449.46.127.25532,766
9449.46.128.0/1749.46.128.1 to 49.46.255.25449.46.255.25532,766
9549.47.0.0/1749.47.0.1 to 49.47.127.25449.47.127.25532,766
9649.47.128.0/1749.47.128.1 to 49.47.255.25449.47.255.25532,766
9749.48.0.0/1749.48.0.1 to 49.48.127.25449.48.127.25532,766
9849.48.128.0/1749.48.128.1 to 49.48.255.25449.48.255.25532,766
9949.49.0.0/1749.49.0.1 to 49.49.127.25449.49.127.25532,766
10049.49.128.0/1749.49.128.1 to 49.49.255.25449.49.255.25532,766
10149.50.0.0/1749.50.0.1 to 49.50.127.25449.50.127.25532,766
10249.50.128.0/1749.50.128.1 to 49.50.255.25449.50.255.25532,766
10349.51.0.0/1749.51.0.1 to 49.51.127.25449.51.127.25532,766
10449.51.128.0/1749.51.128.1 to 49.51.255.25449.51.255.25532,766
10549.52.0.0/1749.52.0.1 to 49.52.127.25449.52.127.25532,766
10649.52.128.0/1749.52.128.1 to 49.52.255.25449.52.255.25532,766
10749.53.0.0/1749.53.0.1 to 49.53.127.25449.53.127.25532,766
10849.53.128.0/1749.53.128.1 to 49.53.255.25449.53.255.25532,766
10949.54.0.0/1749.54.0.1 to 49.54.127.25449.54.127.25532,766
11049.54.128.0/1749.54.128.1 to 49.54.255.25449.54.255.25532,766
11149.55.0.0/1749.55.0.1 to 49.55.127.25449.55.127.25532,766
11249.55.128.0/1749.55.128.1 to 49.55.255.25449.55.255.25532,766
11349.56.0.0/1749.56.0.1 to 49.56.127.25449.56.127.25532,766
11449.56.128.0/1749.56.128.1 to 49.56.255.25449.56.255.25532,766
11549.57.0.0/1749.57.0.1 to 49.57.127.25449.57.127.25532,766
11649.57.128.0/1749.57.128.1 to 49.57.255.25449.57.255.25532,766
11749.58.0.0/1749.58.0.1 to 49.58.127.25449.58.127.25532,766
11849.58.128.0/1749.58.128.1 to 49.58.255.25449.58.255.25532,766
11949.59.0.0/1749.59.0.1 to 49.59.127.25449.59.127.25532,766
12049.59.128.0/1749.59.128.1 to 49.59.255.25449.59.255.25532,766
12149.60.0.0/1749.60.0.1 to 49.60.127.25449.60.127.25532,766
12249.60.128.0/1749.60.128.1 to 49.60.255.25449.60.255.25532,766
12349.61.0.0/1749.61.0.1 to 49.61.127.25449.61.127.25532,766
12449.61.128.0/1749.61.128.1 to 49.61.255.25449.61.255.25532,766
12549.62.0.0/1749.62.0.1 to 49.62.127.25449.62.127.25532,766
12649.62.128.0/1749.62.128.1 to 49.62.255.25449.62.255.25532,766
12749.63.0.0/1749.63.0.1 to 49.63.127.25449.63.127.25532,766
12849.63.128.0/1749.63.128.1 to 49.63.255.25449.63.255.25532,766
12949.64.0.0/1749.64.0.1 to 49.64.127.25449.64.127.25532,766
13049.64.128.0/1749.64.128.1 to 49.64.255.25449.64.255.25532,766
13149.65.0.0/1749.65.0.1 to 49.65.127.25449.65.127.25532,766
13249.65.128.0/1749.65.128.1 to 49.65.255.25449.65.255.25532,766
13349.66.0.0/1749.66.0.1 to 49.66.127.25449.66.127.25532,766
13449.66.128.0/1749.66.128.1 to 49.66.255.25449.66.255.25532,766
13549.67.0.0/1749.67.0.1 to 49.67.127.25449.67.127.25532,766
13649.67.128.0/1749.67.128.1 to 49.67.255.25449.67.255.25532,766
13749.68.0.0/1749.68.0.1 to 49.68.127.25449.68.127.25532,766
13849.68.128.0/1749.68.128.1 to 49.68.255.25449.68.255.25532,766
13949.69.0.0/1749.69.0.1 to 49.69.127.25449.69.127.25532,766
14049.69.128.0/1749.69.128.1 to 49.69.255.25449.69.255.25532,766
14149.70.0.0/1749.70.0.1 to 49.70.127.25449.70.127.25532,766
14249.70.128.0/1749.70.128.1 to 49.70.255.25449.70.255.25532,766
14349.71.0.0/1749.71.0.1 to 49.71.127.25449.71.127.25532,766
14449.71.128.0/1749.71.128.1 to 49.71.255.25449.71.255.25532,766
14549.72.0.0/1749.72.0.1 to 49.72.127.25449.72.127.25532,766
14649.72.128.0/1749.72.128.1 to 49.72.255.25449.72.255.25532,766
14749.73.0.0/1749.73.0.1 to 49.73.127.25449.73.127.25532,766
14849.73.128.0/1749.73.128.1 to 49.73.255.25449.73.255.25532,766
14949.74.0.0/1749.74.0.1 to 49.74.127.25449.74.127.25532,766
15049.74.128.0/1749.74.128.1 to 49.74.255.25449.74.255.25532,766
15149.75.0.0/1749.75.0.1 to 49.75.127.25449.75.127.25532,766
15249.75.128.0/1749.75.128.1 to 49.75.255.25449.75.255.25532,766
15349.76.0.0/1749.76.0.1 to 49.76.127.25449.76.127.25532,766
15449.76.128.0/1749.76.128.1 to 49.76.255.25449.76.255.25532,766
15549.77.0.0/1749.77.0.1 to 49.77.127.25449.77.127.25532,766
15649.77.128.0/1749.77.128.1 to 49.77.255.25449.77.255.25532,766
15749.78.0.0/1749.78.0.1 to 49.78.127.25449.78.127.25532,766
15849.78.128.0/1749.78.128.1 to 49.78.255.25449.78.255.25532,766
15949.79.0.0/1749.79.0.1 to 49.79.127.25449.79.127.25532,766
16049.79.128.0/1749.79.128.1 to 49.79.255.25449.79.255.25532,766
16149.80.0.0/1749.80.0.1 to 49.80.127.25449.80.127.25532,766
16249.80.128.0/1749.80.128.1 to 49.80.255.25449.80.255.25532,766
16349.81.0.0/1749.81.0.1 to 49.81.127.25449.81.127.25532,766
16449.81.128.0/1749.81.128.1 to 49.81.255.25449.81.255.25532,766
16549.82.0.0/1749.82.0.1 to 49.82.127.25449.82.127.25532,766
16649.82.128.0/1749.82.128.1 to 49.82.255.25449.82.255.25532,766
16749.83.0.0/1749.83.0.1 to 49.83.127.25449.83.127.25532,766
16849.83.128.0/1749.83.128.1 to 49.83.255.25449.83.255.25532,766
16949.84.0.0/1749.84.0.1 to 49.84.127.25449.84.127.25532,766
17049.84.128.0/1749.84.128.1 to 49.84.255.25449.84.255.25532,766
17149.85.0.0/1749.85.0.1 to 49.85.127.25449.85.127.25532,766
17249.85.128.0/1749.85.128.1 to 49.85.255.25449.85.255.25532,766
17349.86.0.0/1749.86.0.1 to 49.86.127.25449.86.127.25532,766
17449.86.128.0/1749.86.128.1 to 49.86.255.25449.86.255.25532,766
17549.87.0.0/1749.87.0.1 to 49.87.127.25449.87.127.25532,766
17649.87.128.0/1749.87.128.1 to 49.87.255.25449.87.255.25532,766
17749.88.0.0/1749.88.0.1 to 49.88.127.25449.88.127.25532,766
17849.88.128.0/1749.88.128.1 to 49.88.255.25449.88.255.25532,766
17949.89.0.0/1749.89.0.1 to 49.89.127.25449.89.127.25532,766
18049.89.128.0/1749.89.128.1 to 49.89.255.25449.89.255.25532,766
18149.90.0.0/1749.90.0.1 to 49.90.127.25449.90.127.25532,766
18249.90.128.0/1749.90.128.1 to 49.90.255.25449.90.255.25532,766
18349.91.0.0/1749.91.0.1 to 49.91.127.25449.91.127.25532,766
18449.91.128.0/1749.91.128.1 to 49.91.255.25449.91.255.25532,766
18549.92.0.0/1749.92.0.1 to 49.92.127.25449.92.127.25532,766
18649.92.128.0/1749.92.128.1 to 49.92.255.25449.92.255.25532,766
18749.93.0.0/1749.93.0.1 to 49.93.127.25449.93.127.25532,766
18849.93.128.0/1749.93.128.1 to 49.93.255.25449.93.255.25532,766
18949.94.0.0/1749.94.0.1 to 49.94.127.25449.94.127.25532,766
19049.94.128.0/1749.94.128.1 to 49.94.255.25449.94.255.25532,766
19149.95.0.0/1749.95.0.1 to 49.95.127.25449.95.127.25532,766
19249.95.128.0/1749.95.128.1 to 49.95.255.25449.95.255.25532,766
19349.96.0.0/1749.96.0.1 to 49.96.127.25449.96.127.25532,766
19449.96.128.0/1749.96.128.1 to 49.96.255.25449.96.255.25532,766
19549.97.0.0/1749.97.0.1 to 49.97.127.25449.97.127.25532,766
19649.97.128.0/1749.97.128.1 to 49.97.255.25449.97.255.25532,766
19749.98.0.0/1749.98.0.1 to 49.98.127.25449.98.127.25532,766
19849.98.128.0/1749.98.128.1 to 49.98.255.25449.98.255.25532,766
19949.99.0.0/1749.99.0.1 to 49.99.127.25449.99.127.25532,766
20049.99.128.0/1749.99.128.1 to 49.99.255.25449.99.255.25532,766
20149.100.0.0/1749.100.0.1 to 49.100.127.25449.100.127.25532,766
20249.100.128.0/1749.100.128.1 to 49.100.255.25449.100.255.25532,766
20349.101.0.0/1749.101.0.1 to 49.101.127.25449.101.127.25532,766
20449.101.128.0/1749.101.128.1 to 49.101.255.25449.101.255.25532,766
20549.102.0.0/1749.102.0.1 to 49.102.127.25449.102.127.25532,766
20649.102.128.0/1749.102.128.1 to 49.102.255.25449.102.255.25532,766
20749.103.0.0/1749.103.0.1 to 49.103.127.25449.103.127.25532,766
20849.103.128.0/1749.103.128.1 to 49.103.255.25449.103.255.25532,766
20949.104.0.0/1749.104.0.1 to 49.104.127.25449.104.127.25532,766
21049.104.128.0/1749.104.128.1 to 49.104.255.25449.104.255.25532,766
21149.105.0.0/1749.105.0.1 to 49.105.127.25449.105.127.25532,766
21249.105.128.0/1749.105.128.1 to 49.105.255.25449.105.255.25532,766
21349.106.0.0/1749.106.0.1 to 49.106.127.25449.106.127.25532,766
21449.106.128.0/1749.106.128.1 to 49.106.255.25449.106.255.25532,766
21549.107.0.0/1749.107.0.1 to 49.107.127.25449.107.127.25532,766
21649.107.128.0/1749.107.128.1 to 49.107.255.25449.107.255.25532,766
21749.108.0.0/1749.108.0.1 to 49.108.127.25449.108.127.25532,766
21849.108.128.0/1749.108.128.1 to 49.108.255.25449.108.255.25532,766
21949.109.0.0/1749.109.0.1 to 49.109.127.25449.109.127.25532,766
22049.109.128.0/1749.109.128.1 to 49.109.255.25449.109.255.25532,766
22149.110.0.0/1749.110.0.1 to 49.110.127.25449.110.127.25532,766
22249.110.128.0/1749.110.128.1 to 49.110.255.25449.110.255.25532,766
22349.111.0.0/1749.111.0.1 to 49.111.127.25449.111.127.25532,766
22449.111.128.0/1749.111.128.1 to 49.111.255.25449.111.255.25532,766
22549.112.0.0/1749.112.0.1 to 49.112.127.25449.112.127.25532,766
22649.112.128.0/1749.112.128.1 to 49.112.255.25449.112.255.25532,766
22749.113.0.0/1749.113.0.1 to 49.113.127.25449.113.127.25532,766
22849.113.128.0/1749.113.128.1 to 49.113.255.25449.113.255.25532,766
22949.114.0.0/1749.114.0.1 to 49.114.127.25449.114.127.25532,766
23049.114.128.0/1749.114.128.1 to 49.114.255.25449.114.255.25532,766
23149.115.0.0/1749.115.0.1 to 49.115.127.25449.115.127.25532,766
23249.115.128.0/1749.115.128.1 to 49.115.255.25449.115.255.25532,766
23349.116.0.0/1749.116.0.1 to 49.116.127.25449.116.127.25532,766
23449.116.128.0/1749.116.128.1 to 49.116.255.25449.116.255.25532,766
23549.117.0.0/1749.117.0.1 to 49.117.127.25449.117.127.25532,766
23649.117.128.0/1749.117.128.1 to 49.117.255.25449.117.255.25532,766
23749.118.0.0/1749.118.0.1 to 49.118.127.25449.118.127.25532,766
23849.118.128.0/1749.118.128.1 to 49.118.255.25449.118.255.25532,766
23949.119.0.0/1749.119.0.1 to 49.119.127.25449.119.127.25532,766
24049.119.128.0/1749.119.128.1 to 49.119.255.25449.119.255.25532,766
24149.120.0.0/1749.120.0.1 to 49.120.127.25449.120.127.25532,766
24249.120.128.0/1749.120.128.1 to 49.120.255.25449.120.255.25532,766
24349.121.0.0/1749.121.0.1 to 49.121.127.25449.121.127.25532,766
24449.121.128.0/1749.121.128.1 to 49.121.255.25449.121.255.25532,766
24549.122.0.0/1749.122.0.1 to 49.122.127.25449.122.127.25532,766
24649.122.128.0/1749.122.128.1 to 49.122.255.25449.122.255.25532,766
24749.123.0.0/1749.123.0.1 to 49.123.127.25449.123.127.25532,766
24849.123.128.0/1749.123.128.1 to 49.123.255.25449.123.255.25532,766
24949.124.0.0/1749.124.0.1 to 49.124.127.25449.124.127.25532,766
25049.124.128.0/1749.124.128.1 to 49.124.255.25449.124.255.25532,766
25149.125.0.0/1749.125.0.1 to 49.125.127.25449.125.127.25532,766
25249.125.128.0/1749.125.128.1 to 49.125.255.25449.125.255.25532,766
25349.126.0.0/1749.126.0.1 to 49.126.127.25449.126.127.25532,766
25449.126.128.0/1749.126.128.1 to 49.126.255.25449.126.255.25532,766
25549.127.0.0/1749.127.0.1 to 49.127.127.25449.127.127.25532,766
25649.127.128.0/1749.127.128.1 to 49.127.255.25449.127.255.25532,766

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.