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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.

Network59.72.0.0/15
Usable hosts131,070
Subnet mask255.254.0.0
Addresses131,072
Network address
59.72.0.0
Broadcast address
59.73.255.255
First usable
59.72.0.1
Last usable
59.73.255.254
Usable hosts
131,070 (131,072 less the network and broadcast addresses)
Subnet mask
255.254.0.0
Wildcard mask
0.1.255.255 (Cisco ACLs, OSPF)
Prefix length
/15
Type
Public public
Old class
A (default /8)
As numbers
Hex 3B480000 · Integer 994574336 to 994705407
Reverse DNS zones
72.59.in-addr.arpa
73.59.in-addr.arpa
/15 is not on a 8-bit boundary, so it takes 2 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address00111011.01001000.00000000.0000000059.72.0.0
Subnet mask11111111.11111110.00000000.00000000255.254.0.0
Network00111011.01001000.00000000.0000000059.72.0.0
Broadcast00111011.01001001.11111111.1111111159.73.255.255
Split into smaller subnets/25
/16 (2)/17 (4)/18 (8)/19 (16)/20 (32)/21 (64)/22 (128)/23 (256)/24 (512)/25 (1,024)/26 (2,048)/27 (4,096)

59.72.0.0/15 makes 1,024 subnets of /25; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
159.72.0.0/2559.72.0.1 to 59.72.0.12659.72.0.127126
259.72.0.128/2559.72.0.129 to 59.72.0.25459.72.0.255126
359.72.1.0/2559.72.1.1 to 59.72.1.12659.72.1.127126
459.72.1.128/2559.72.1.129 to 59.72.1.25459.72.1.255126
559.72.2.0/2559.72.2.1 to 59.72.2.12659.72.2.127126
659.72.2.128/2559.72.2.129 to 59.72.2.25459.72.2.255126
759.72.3.0/2559.72.3.1 to 59.72.3.12659.72.3.127126
859.72.3.128/2559.72.3.129 to 59.72.3.25459.72.3.255126
959.72.4.0/2559.72.4.1 to 59.72.4.12659.72.4.127126
1059.72.4.128/2559.72.4.129 to 59.72.4.25459.72.4.255126
1159.72.5.0/2559.72.5.1 to 59.72.5.12659.72.5.127126
1259.72.5.128/2559.72.5.129 to 59.72.5.25459.72.5.255126
1359.72.6.0/2559.72.6.1 to 59.72.6.12659.72.6.127126
1459.72.6.128/2559.72.6.129 to 59.72.6.25459.72.6.255126
1559.72.7.0/2559.72.7.1 to 59.72.7.12659.72.7.127126
1659.72.7.128/2559.72.7.129 to 59.72.7.25459.72.7.255126
1759.72.8.0/2559.72.8.1 to 59.72.8.12659.72.8.127126
1859.72.8.128/2559.72.8.129 to 59.72.8.25459.72.8.255126
1959.72.9.0/2559.72.9.1 to 59.72.9.12659.72.9.127126
2059.72.9.128/2559.72.9.129 to 59.72.9.25459.72.9.255126
2159.72.10.0/2559.72.10.1 to 59.72.10.12659.72.10.127126
2259.72.10.128/2559.72.10.129 to 59.72.10.25459.72.10.255126
2359.72.11.0/2559.72.11.1 to 59.72.11.12659.72.11.127126
2459.72.11.128/2559.72.11.129 to 59.72.11.25459.72.11.255126
2559.72.12.0/2559.72.12.1 to 59.72.12.12659.72.12.127126
2659.72.12.128/2559.72.12.129 to 59.72.12.25459.72.12.255126
2759.72.13.0/2559.72.13.1 to 59.72.13.12659.72.13.127126
2859.72.13.128/2559.72.13.129 to 59.72.13.25459.72.13.255126
2959.72.14.0/2559.72.14.1 to 59.72.14.12659.72.14.127126
3059.72.14.128/2559.72.14.129 to 59.72.14.25459.72.14.255126
3159.72.15.0/2559.72.15.1 to 59.72.15.12659.72.15.127126
3259.72.15.128/2559.72.15.129 to 59.72.15.25459.72.15.255126
3359.72.16.0/2559.72.16.1 to 59.72.16.12659.72.16.127126
3459.72.16.128/2559.72.16.129 to 59.72.16.25459.72.16.255126
3559.72.17.0/2559.72.17.1 to 59.72.17.12659.72.17.127126
3659.72.17.128/2559.72.17.129 to 59.72.17.25459.72.17.255126
3759.72.18.0/2559.72.18.1 to 59.72.18.12659.72.18.127126
3859.72.18.128/2559.72.18.129 to 59.72.18.25459.72.18.255126
3959.72.19.0/2559.72.19.1 to 59.72.19.12659.72.19.127126
4059.72.19.128/2559.72.19.129 to 59.72.19.25459.72.19.255126
4159.72.20.0/2559.72.20.1 to 59.72.20.12659.72.20.127126
4259.72.20.128/2559.72.20.129 to 59.72.20.25459.72.20.255126
4359.72.21.0/2559.72.21.1 to 59.72.21.12659.72.21.127126
4459.72.21.128/2559.72.21.129 to 59.72.21.25459.72.21.255126
4559.72.22.0/2559.72.22.1 to 59.72.22.12659.72.22.127126
4659.72.22.128/2559.72.22.129 to 59.72.22.25459.72.22.255126
4759.72.23.0/2559.72.23.1 to 59.72.23.12659.72.23.127126
4859.72.23.128/2559.72.23.129 to 59.72.23.25459.72.23.255126
4959.72.24.0/2559.72.24.1 to 59.72.24.12659.72.24.127126
5059.72.24.128/2559.72.24.129 to 59.72.24.25459.72.24.255126
5159.72.25.0/2559.72.25.1 to 59.72.25.12659.72.25.127126
5259.72.25.128/2559.72.25.129 to 59.72.25.25459.72.25.255126
5359.72.26.0/2559.72.26.1 to 59.72.26.12659.72.26.127126
5459.72.26.128/2559.72.26.129 to 59.72.26.25459.72.26.255126
5559.72.27.0/2559.72.27.1 to 59.72.27.12659.72.27.127126
5659.72.27.128/2559.72.27.129 to 59.72.27.25459.72.27.255126
5759.72.28.0/2559.72.28.1 to 59.72.28.12659.72.28.127126
5859.72.28.128/2559.72.28.129 to 59.72.28.25459.72.28.255126
5959.72.29.0/2559.72.29.1 to 59.72.29.12659.72.29.127126
6059.72.29.128/2559.72.29.129 to 59.72.29.25459.72.29.255126
6159.72.30.0/2559.72.30.1 to 59.72.30.12659.72.30.127126
6259.72.30.128/2559.72.30.129 to 59.72.30.25459.72.30.255126
6359.72.31.0/2559.72.31.1 to 59.72.31.12659.72.31.127126
6459.72.31.128/2559.72.31.129 to 59.72.31.25459.72.31.255126
6559.72.32.0/2559.72.32.1 to 59.72.32.12659.72.32.127126
6659.72.32.128/2559.72.32.129 to 59.72.32.25459.72.32.255126
6759.72.33.0/2559.72.33.1 to 59.72.33.12659.72.33.127126
6859.72.33.128/2559.72.33.129 to 59.72.33.25459.72.33.255126
6959.72.34.0/2559.72.34.1 to 59.72.34.12659.72.34.127126
7059.72.34.128/2559.72.34.129 to 59.72.34.25459.72.34.255126
7159.72.35.0/2559.72.35.1 to 59.72.35.12659.72.35.127126
7259.72.35.128/2559.72.35.129 to 59.72.35.25459.72.35.255126
7359.72.36.0/2559.72.36.1 to 59.72.36.12659.72.36.127126
7459.72.36.128/2559.72.36.129 to 59.72.36.25459.72.36.255126
7559.72.37.0/2559.72.37.1 to 59.72.37.12659.72.37.127126
7659.72.37.128/2559.72.37.129 to 59.72.37.25459.72.37.255126
7759.72.38.0/2559.72.38.1 to 59.72.38.12659.72.38.127126
7859.72.38.128/2559.72.38.129 to 59.72.38.25459.72.38.255126
7959.72.39.0/2559.72.39.1 to 59.72.39.12659.72.39.127126
8059.72.39.128/2559.72.39.129 to 59.72.39.25459.72.39.255126
8159.72.40.0/2559.72.40.1 to 59.72.40.12659.72.40.127126
8259.72.40.128/2559.72.40.129 to 59.72.40.25459.72.40.255126
8359.72.41.0/2559.72.41.1 to 59.72.41.12659.72.41.127126
8459.72.41.128/2559.72.41.129 to 59.72.41.25459.72.41.255126
8559.72.42.0/2559.72.42.1 to 59.72.42.12659.72.42.127126
8659.72.42.128/2559.72.42.129 to 59.72.42.25459.72.42.255126
8759.72.43.0/2559.72.43.1 to 59.72.43.12659.72.43.127126
8859.72.43.128/2559.72.43.129 to 59.72.43.25459.72.43.255126
8959.72.44.0/2559.72.44.1 to 59.72.44.12659.72.44.127126
9059.72.44.128/2559.72.44.129 to 59.72.44.25459.72.44.255126
9159.72.45.0/2559.72.45.1 to 59.72.45.12659.72.45.127126
9259.72.45.128/2559.72.45.129 to 59.72.45.25459.72.45.255126
9359.72.46.0/2559.72.46.1 to 59.72.46.12659.72.46.127126
9459.72.46.128/2559.72.46.129 to 59.72.46.25459.72.46.255126
9559.72.47.0/2559.72.47.1 to 59.72.47.12659.72.47.127126
9659.72.47.128/2559.72.47.129 to 59.72.47.25459.72.47.255126
9759.72.48.0/2559.72.48.1 to 59.72.48.12659.72.48.127126
9859.72.48.128/2559.72.48.129 to 59.72.48.25459.72.48.255126
9959.72.49.0/2559.72.49.1 to 59.72.49.12659.72.49.127126
10059.72.49.128/2559.72.49.129 to 59.72.49.25459.72.49.255126
10159.72.50.0/2559.72.50.1 to 59.72.50.12659.72.50.127126
10259.72.50.128/2559.72.50.129 to 59.72.50.25459.72.50.255126
10359.72.51.0/2559.72.51.1 to 59.72.51.12659.72.51.127126
10459.72.51.128/2559.72.51.129 to 59.72.51.25459.72.51.255126
10559.72.52.0/2559.72.52.1 to 59.72.52.12659.72.52.127126
10659.72.52.128/2559.72.52.129 to 59.72.52.25459.72.52.255126
10759.72.53.0/2559.72.53.1 to 59.72.53.12659.72.53.127126
10859.72.53.128/2559.72.53.129 to 59.72.53.25459.72.53.255126
10959.72.54.0/2559.72.54.1 to 59.72.54.12659.72.54.127126
11059.72.54.128/2559.72.54.129 to 59.72.54.25459.72.54.255126
11159.72.55.0/2559.72.55.1 to 59.72.55.12659.72.55.127126
11259.72.55.128/2559.72.55.129 to 59.72.55.25459.72.55.255126
11359.72.56.0/2559.72.56.1 to 59.72.56.12659.72.56.127126
11459.72.56.128/2559.72.56.129 to 59.72.56.25459.72.56.255126
11559.72.57.0/2559.72.57.1 to 59.72.57.12659.72.57.127126
11659.72.57.128/2559.72.57.129 to 59.72.57.25459.72.57.255126
11759.72.58.0/2559.72.58.1 to 59.72.58.12659.72.58.127126
11859.72.58.128/2559.72.58.129 to 59.72.58.25459.72.58.255126
11959.72.59.0/2559.72.59.1 to 59.72.59.12659.72.59.127126
12059.72.59.128/2559.72.59.129 to 59.72.59.25459.72.59.255126
12159.72.60.0/2559.72.60.1 to 59.72.60.12659.72.60.127126
12259.72.60.128/2559.72.60.129 to 59.72.60.25459.72.60.255126
12359.72.61.0/2559.72.61.1 to 59.72.61.12659.72.61.127126
12459.72.61.128/2559.72.61.129 to 59.72.61.25459.72.61.255126
12559.72.62.0/2559.72.62.1 to 59.72.62.12659.72.62.127126
12659.72.62.128/2559.72.62.129 to 59.72.62.25459.72.62.255126
12759.72.63.0/2559.72.63.1 to 59.72.63.12659.72.63.127126
12859.72.63.128/2559.72.63.129 to 59.72.63.25459.72.63.255126
12959.72.64.0/2559.72.64.1 to 59.72.64.12659.72.64.127126
13059.72.64.128/2559.72.64.129 to 59.72.64.25459.72.64.255126
13159.72.65.0/2559.72.65.1 to 59.72.65.12659.72.65.127126
13259.72.65.128/2559.72.65.129 to 59.72.65.25459.72.65.255126
13359.72.66.0/2559.72.66.1 to 59.72.66.12659.72.66.127126
13459.72.66.128/2559.72.66.129 to 59.72.66.25459.72.66.255126
13559.72.67.0/2559.72.67.1 to 59.72.67.12659.72.67.127126
13659.72.67.128/2559.72.67.129 to 59.72.67.25459.72.67.255126
13759.72.68.0/2559.72.68.1 to 59.72.68.12659.72.68.127126
13859.72.68.128/2559.72.68.129 to 59.72.68.25459.72.68.255126
13959.72.69.0/2559.72.69.1 to 59.72.69.12659.72.69.127126
14059.72.69.128/2559.72.69.129 to 59.72.69.25459.72.69.255126
14159.72.70.0/2559.72.70.1 to 59.72.70.12659.72.70.127126
14259.72.70.128/2559.72.70.129 to 59.72.70.25459.72.70.255126
14359.72.71.0/2559.72.71.1 to 59.72.71.12659.72.71.127126
14459.72.71.128/2559.72.71.129 to 59.72.71.25459.72.71.255126
14559.72.72.0/2559.72.72.1 to 59.72.72.12659.72.72.127126
14659.72.72.128/2559.72.72.129 to 59.72.72.25459.72.72.255126
14759.72.73.0/2559.72.73.1 to 59.72.73.12659.72.73.127126
14859.72.73.128/2559.72.73.129 to 59.72.73.25459.72.73.255126
14959.72.74.0/2559.72.74.1 to 59.72.74.12659.72.74.127126
15059.72.74.128/2559.72.74.129 to 59.72.74.25459.72.74.255126
15159.72.75.0/2559.72.75.1 to 59.72.75.12659.72.75.127126
15259.72.75.128/2559.72.75.129 to 59.72.75.25459.72.75.255126
15359.72.76.0/2559.72.76.1 to 59.72.76.12659.72.76.127126
15459.72.76.128/2559.72.76.129 to 59.72.76.25459.72.76.255126
15559.72.77.0/2559.72.77.1 to 59.72.77.12659.72.77.127126
15659.72.77.128/2559.72.77.129 to 59.72.77.25459.72.77.255126
15759.72.78.0/2559.72.78.1 to 59.72.78.12659.72.78.127126
15859.72.78.128/2559.72.78.129 to 59.72.78.25459.72.78.255126
15959.72.79.0/2559.72.79.1 to 59.72.79.12659.72.79.127126
16059.72.79.128/2559.72.79.129 to 59.72.79.25459.72.79.255126
16159.72.80.0/2559.72.80.1 to 59.72.80.12659.72.80.127126
16259.72.80.128/2559.72.80.129 to 59.72.80.25459.72.80.255126
16359.72.81.0/2559.72.81.1 to 59.72.81.12659.72.81.127126
16459.72.81.128/2559.72.81.129 to 59.72.81.25459.72.81.255126
16559.72.82.0/2559.72.82.1 to 59.72.82.12659.72.82.127126
16659.72.82.128/2559.72.82.129 to 59.72.82.25459.72.82.255126
16759.72.83.0/2559.72.83.1 to 59.72.83.12659.72.83.127126
16859.72.83.128/2559.72.83.129 to 59.72.83.25459.72.83.255126
16959.72.84.0/2559.72.84.1 to 59.72.84.12659.72.84.127126
17059.72.84.128/2559.72.84.129 to 59.72.84.25459.72.84.255126
17159.72.85.0/2559.72.85.1 to 59.72.85.12659.72.85.127126
17259.72.85.128/2559.72.85.129 to 59.72.85.25459.72.85.255126
17359.72.86.0/2559.72.86.1 to 59.72.86.12659.72.86.127126
17459.72.86.128/2559.72.86.129 to 59.72.86.25459.72.86.255126
17559.72.87.0/2559.72.87.1 to 59.72.87.12659.72.87.127126
17659.72.87.128/2559.72.87.129 to 59.72.87.25459.72.87.255126
17759.72.88.0/2559.72.88.1 to 59.72.88.12659.72.88.127126
17859.72.88.128/2559.72.88.129 to 59.72.88.25459.72.88.255126
17959.72.89.0/2559.72.89.1 to 59.72.89.12659.72.89.127126
18059.72.89.128/2559.72.89.129 to 59.72.89.25459.72.89.255126
18159.72.90.0/2559.72.90.1 to 59.72.90.12659.72.90.127126
18259.72.90.128/2559.72.90.129 to 59.72.90.25459.72.90.255126
18359.72.91.0/2559.72.91.1 to 59.72.91.12659.72.91.127126
18459.72.91.128/2559.72.91.129 to 59.72.91.25459.72.91.255126
18559.72.92.0/2559.72.92.1 to 59.72.92.12659.72.92.127126
18659.72.92.128/2559.72.92.129 to 59.72.92.25459.72.92.255126
18759.72.93.0/2559.72.93.1 to 59.72.93.12659.72.93.127126
18859.72.93.128/2559.72.93.129 to 59.72.93.25459.72.93.255126
18959.72.94.0/2559.72.94.1 to 59.72.94.12659.72.94.127126
19059.72.94.128/2559.72.94.129 to 59.72.94.25459.72.94.255126
19159.72.95.0/2559.72.95.1 to 59.72.95.12659.72.95.127126
19259.72.95.128/2559.72.95.129 to 59.72.95.25459.72.95.255126
19359.72.96.0/2559.72.96.1 to 59.72.96.12659.72.96.127126
19459.72.96.128/2559.72.96.129 to 59.72.96.25459.72.96.255126
19559.72.97.0/2559.72.97.1 to 59.72.97.12659.72.97.127126
19659.72.97.128/2559.72.97.129 to 59.72.97.25459.72.97.255126
19759.72.98.0/2559.72.98.1 to 59.72.98.12659.72.98.127126
19859.72.98.128/2559.72.98.129 to 59.72.98.25459.72.98.255126
19959.72.99.0/2559.72.99.1 to 59.72.99.12659.72.99.127126
20059.72.99.128/2559.72.99.129 to 59.72.99.25459.72.99.255126
20159.72.100.0/2559.72.100.1 to 59.72.100.12659.72.100.127126
20259.72.100.128/2559.72.100.129 to 59.72.100.25459.72.100.255126
20359.72.101.0/2559.72.101.1 to 59.72.101.12659.72.101.127126
20459.72.101.128/2559.72.101.129 to 59.72.101.25459.72.101.255126
20559.72.102.0/2559.72.102.1 to 59.72.102.12659.72.102.127126
20659.72.102.128/2559.72.102.129 to 59.72.102.25459.72.102.255126
20759.72.103.0/2559.72.103.1 to 59.72.103.12659.72.103.127126
20859.72.103.128/2559.72.103.129 to 59.72.103.25459.72.103.255126
20959.72.104.0/2559.72.104.1 to 59.72.104.12659.72.104.127126
21059.72.104.128/2559.72.104.129 to 59.72.104.25459.72.104.255126
21159.72.105.0/2559.72.105.1 to 59.72.105.12659.72.105.127126
21259.72.105.128/2559.72.105.129 to 59.72.105.25459.72.105.255126
21359.72.106.0/2559.72.106.1 to 59.72.106.12659.72.106.127126
21459.72.106.128/2559.72.106.129 to 59.72.106.25459.72.106.255126
21559.72.107.0/2559.72.107.1 to 59.72.107.12659.72.107.127126
21659.72.107.128/2559.72.107.129 to 59.72.107.25459.72.107.255126
21759.72.108.0/2559.72.108.1 to 59.72.108.12659.72.108.127126
21859.72.108.128/2559.72.108.129 to 59.72.108.25459.72.108.255126
21959.72.109.0/2559.72.109.1 to 59.72.109.12659.72.109.127126
22059.72.109.128/2559.72.109.129 to 59.72.109.25459.72.109.255126
22159.72.110.0/2559.72.110.1 to 59.72.110.12659.72.110.127126
22259.72.110.128/2559.72.110.129 to 59.72.110.25459.72.110.255126
22359.72.111.0/2559.72.111.1 to 59.72.111.12659.72.111.127126
22459.72.111.128/2559.72.111.129 to 59.72.111.25459.72.111.255126
22559.72.112.0/2559.72.112.1 to 59.72.112.12659.72.112.127126
22659.72.112.128/2559.72.112.129 to 59.72.112.25459.72.112.255126
22759.72.113.0/2559.72.113.1 to 59.72.113.12659.72.113.127126
22859.72.113.128/2559.72.113.129 to 59.72.113.25459.72.113.255126
22959.72.114.0/2559.72.114.1 to 59.72.114.12659.72.114.127126
23059.72.114.128/2559.72.114.129 to 59.72.114.25459.72.114.255126
23159.72.115.0/2559.72.115.1 to 59.72.115.12659.72.115.127126
23259.72.115.128/2559.72.115.129 to 59.72.115.25459.72.115.255126
23359.72.116.0/2559.72.116.1 to 59.72.116.12659.72.116.127126
23459.72.116.128/2559.72.116.129 to 59.72.116.25459.72.116.255126
23559.72.117.0/2559.72.117.1 to 59.72.117.12659.72.117.127126
23659.72.117.128/2559.72.117.129 to 59.72.117.25459.72.117.255126
23759.72.118.0/2559.72.118.1 to 59.72.118.12659.72.118.127126
23859.72.118.128/2559.72.118.129 to 59.72.118.25459.72.118.255126
23959.72.119.0/2559.72.119.1 to 59.72.119.12659.72.119.127126
24059.72.119.128/2559.72.119.129 to 59.72.119.25459.72.119.255126
24159.72.120.0/2559.72.120.1 to 59.72.120.12659.72.120.127126
24259.72.120.128/2559.72.120.129 to 59.72.120.25459.72.120.255126
24359.72.121.0/2559.72.121.1 to 59.72.121.12659.72.121.127126
24459.72.121.128/2559.72.121.129 to 59.72.121.25459.72.121.255126
24559.72.122.0/2559.72.122.1 to 59.72.122.12659.72.122.127126
24659.72.122.128/2559.72.122.129 to 59.72.122.25459.72.122.255126
24759.72.123.0/2559.72.123.1 to 59.72.123.12659.72.123.127126
24859.72.123.128/2559.72.123.129 to 59.72.123.25459.72.123.255126
24959.72.124.0/2559.72.124.1 to 59.72.124.12659.72.124.127126
25059.72.124.128/2559.72.124.129 to 59.72.124.25459.72.124.255126
25159.72.125.0/2559.72.125.1 to 59.72.125.12659.72.125.127126
25259.72.125.128/2559.72.125.129 to 59.72.125.25459.72.125.255126
25359.72.126.0/2559.72.126.1 to 59.72.126.12659.72.126.127126
25459.72.126.128/2559.72.126.129 to 59.72.126.25459.72.126.255126
25559.72.127.0/2559.72.127.1 to 59.72.127.12659.72.127.127126
25659.72.127.128/2559.72.127.129 to 59.72.127.25459.72.127.255126

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.