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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.

Network48.167.0.0/17
Usable hosts32,766
Subnet mask255.255.128.0
Addresses32,768
Network address
48.167.0.0
Broadcast address
48.167.127.255
First usable
48.167.0.1
Last usable
48.167.127.254
Usable hosts
32,766 (32,768 less the network and broadcast addresses)
Subnet mask
255.255.128.0
Wildcard mask
0.0.127.255 (Cisco ACLs, OSPF)
Prefix length
/17
Type
Public public
Old class
A (default /8)
As numbers
Hex 30A70000 · Integer 816250880 to 816283647
Reverse DNS zones
0.167.48.in-addr.arpa
1.167.48.in-addr.arpa
2.167.48.in-addr.arpa
3.167.48.in-addr.arpa
4.167.48.in-addr.arpa
5.167.48.in-addr.arpa
6.167.48.in-addr.arpa
7.167.48.in-addr.arpa
8.167.48.in-addr.arpa
9.167.48.in-addr.arpa
10.167.48.in-addr.arpa
11.167.48.in-addr.arpa
12.167.48.in-addr.arpa
13.167.48.in-addr.arpa
14.167.48.in-addr.arpa
15.167.48.in-addr.arpa
and 112 more
/17 is not on a 8-bit boundary, so it takes 128 /24 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address00110000.10100111.00000000.0000000048.167.0.0
Subnet mask11111111.11111111.10000000.00000000255.255.128.0
Network00110000.10100111.00000000.0000000048.167.0.0
Broadcast00110000.10100111.01111111.1111111148.167.127.255
Split into smaller subnets/25
/18 (2)/19 (4)/20 (8)/21 (16)/22 (32)/23 (64)/24 (128)/25 (256)/26 (512)/27 (1,024)/28 (2,048)/29 (4,096)

48.167.0.0/17 makes 256 subnets of /25.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
148.167.0.0/2548.167.0.1 to 48.167.0.12648.167.0.127126
248.167.0.128/2548.167.0.129 to 48.167.0.25448.167.0.255126
348.167.1.0/2548.167.1.1 to 48.167.1.12648.167.1.127126
448.167.1.128/2548.167.1.129 to 48.167.1.25448.167.1.255126
548.167.2.0/2548.167.2.1 to 48.167.2.12648.167.2.127126
648.167.2.128/2548.167.2.129 to 48.167.2.25448.167.2.255126
748.167.3.0/2548.167.3.1 to 48.167.3.12648.167.3.127126
848.167.3.128/2548.167.3.129 to 48.167.3.25448.167.3.255126
948.167.4.0/2548.167.4.1 to 48.167.4.12648.167.4.127126
1048.167.4.128/2548.167.4.129 to 48.167.4.25448.167.4.255126
1148.167.5.0/2548.167.5.1 to 48.167.5.12648.167.5.127126
1248.167.5.128/2548.167.5.129 to 48.167.5.25448.167.5.255126
1348.167.6.0/2548.167.6.1 to 48.167.6.12648.167.6.127126
1448.167.6.128/2548.167.6.129 to 48.167.6.25448.167.6.255126
1548.167.7.0/2548.167.7.1 to 48.167.7.12648.167.7.127126
1648.167.7.128/2548.167.7.129 to 48.167.7.25448.167.7.255126
1748.167.8.0/2548.167.8.1 to 48.167.8.12648.167.8.127126
1848.167.8.128/2548.167.8.129 to 48.167.8.25448.167.8.255126
1948.167.9.0/2548.167.9.1 to 48.167.9.12648.167.9.127126
2048.167.9.128/2548.167.9.129 to 48.167.9.25448.167.9.255126
2148.167.10.0/2548.167.10.1 to 48.167.10.12648.167.10.127126
2248.167.10.128/2548.167.10.129 to 48.167.10.25448.167.10.255126
2348.167.11.0/2548.167.11.1 to 48.167.11.12648.167.11.127126
2448.167.11.128/2548.167.11.129 to 48.167.11.25448.167.11.255126
2548.167.12.0/2548.167.12.1 to 48.167.12.12648.167.12.127126
2648.167.12.128/2548.167.12.129 to 48.167.12.25448.167.12.255126
2748.167.13.0/2548.167.13.1 to 48.167.13.12648.167.13.127126
2848.167.13.128/2548.167.13.129 to 48.167.13.25448.167.13.255126
2948.167.14.0/2548.167.14.1 to 48.167.14.12648.167.14.127126
3048.167.14.128/2548.167.14.129 to 48.167.14.25448.167.14.255126
3148.167.15.0/2548.167.15.1 to 48.167.15.12648.167.15.127126
3248.167.15.128/2548.167.15.129 to 48.167.15.25448.167.15.255126
3348.167.16.0/2548.167.16.1 to 48.167.16.12648.167.16.127126
3448.167.16.128/2548.167.16.129 to 48.167.16.25448.167.16.255126
3548.167.17.0/2548.167.17.1 to 48.167.17.12648.167.17.127126
3648.167.17.128/2548.167.17.129 to 48.167.17.25448.167.17.255126
3748.167.18.0/2548.167.18.1 to 48.167.18.12648.167.18.127126
3848.167.18.128/2548.167.18.129 to 48.167.18.25448.167.18.255126
3948.167.19.0/2548.167.19.1 to 48.167.19.12648.167.19.127126
4048.167.19.128/2548.167.19.129 to 48.167.19.25448.167.19.255126
4148.167.20.0/2548.167.20.1 to 48.167.20.12648.167.20.127126
4248.167.20.128/2548.167.20.129 to 48.167.20.25448.167.20.255126
4348.167.21.0/2548.167.21.1 to 48.167.21.12648.167.21.127126
4448.167.21.128/2548.167.21.129 to 48.167.21.25448.167.21.255126
4548.167.22.0/2548.167.22.1 to 48.167.22.12648.167.22.127126
4648.167.22.128/2548.167.22.129 to 48.167.22.25448.167.22.255126
4748.167.23.0/2548.167.23.1 to 48.167.23.12648.167.23.127126
4848.167.23.128/2548.167.23.129 to 48.167.23.25448.167.23.255126
4948.167.24.0/2548.167.24.1 to 48.167.24.12648.167.24.127126
5048.167.24.128/2548.167.24.129 to 48.167.24.25448.167.24.255126
5148.167.25.0/2548.167.25.1 to 48.167.25.12648.167.25.127126
5248.167.25.128/2548.167.25.129 to 48.167.25.25448.167.25.255126
5348.167.26.0/2548.167.26.1 to 48.167.26.12648.167.26.127126
5448.167.26.128/2548.167.26.129 to 48.167.26.25448.167.26.255126
5548.167.27.0/2548.167.27.1 to 48.167.27.12648.167.27.127126
5648.167.27.128/2548.167.27.129 to 48.167.27.25448.167.27.255126
5748.167.28.0/2548.167.28.1 to 48.167.28.12648.167.28.127126
5848.167.28.128/2548.167.28.129 to 48.167.28.25448.167.28.255126
5948.167.29.0/2548.167.29.1 to 48.167.29.12648.167.29.127126
6048.167.29.128/2548.167.29.129 to 48.167.29.25448.167.29.255126
6148.167.30.0/2548.167.30.1 to 48.167.30.12648.167.30.127126
6248.167.30.128/2548.167.30.129 to 48.167.30.25448.167.30.255126
6348.167.31.0/2548.167.31.1 to 48.167.31.12648.167.31.127126
6448.167.31.128/2548.167.31.129 to 48.167.31.25448.167.31.255126
6548.167.32.0/2548.167.32.1 to 48.167.32.12648.167.32.127126
6648.167.32.128/2548.167.32.129 to 48.167.32.25448.167.32.255126
6748.167.33.0/2548.167.33.1 to 48.167.33.12648.167.33.127126
6848.167.33.128/2548.167.33.129 to 48.167.33.25448.167.33.255126
6948.167.34.0/2548.167.34.1 to 48.167.34.12648.167.34.127126
7048.167.34.128/2548.167.34.129 to 48.167.34.25448.167.34.255126
7148.167.35.0/2548.167.35.1 to 48.167.35.12648.167.35.127126
7248.167.35.128/2548.167.35.129 to 48.167.35.25448.167.35.255126
7348.167.36.0/2548.167.36.1 to 48.167.36.12648.167.36.127126
7448.167.36.128/2548.167.36.129 to 48.167.36.25448.167.36.255126
7548.167.37.0/2548.167.37.1 to 48.167.37.12648.167.37.127126
7648.167.37.128/2548.167.37.129 to 48.167.37.25448.167.37.255126
7748.167.38.0/2548.167.38.1 to 48.167.38.12648.167.38.127126
7848.167.38.128/2548.167.38.129 to 48.167.38.25448.167.38.255126
7948.167.39.0/2548.167.39.1 to 48.167.39.12648.167.39.127126
8048.167.39.128/2548.167.39.129 to 48.167.39.25448.167.39.255126
8148.167.40.0/2548.167.40.1 to 48.167.40.12648.167.40.127126
8248.167.40.128/2548.167.40.129 to 48.167.40.25448.167.40.255126
8348.167.41.0/2548.167.41.1 to 48.167.41.12648.167.41.127126
8448.167.41.128/2548.167.41.129 to 48.167.41.25448.167.41.255126
8548.167.42.0/2548.167.42.1 to 48.167.42.12648.167.42.127126
8648.167.42.128/2548.167.42.129 to 48.167.42.25448.167.42.255126
8748.167.43.0/2548.167.43.1 to 48.167.43.12648.167.43.127126
8848.167.43.128/2548.167.43.129 to 48.167.43.25448.167.43.255126
8948.167.44.0/2548.167.44.1 to 48.167.44.12648.167.44.127126
9048.167.44.128/2548.167.44.129 to 48.167.44.25448.167.44.255126
9148.167.45.0/2548.167.45.1 to 48.167.45.12648.167.45.127126
9248.167.45.128/2548.167.45.129 to 48.167.45.25448.167.45.255126
9348.167.46.0/2548.167.46.1 to 48.167.46.12648.167.46.127126
9448.167.46.128/2548.167.46.129 to 48.167.46.25448.167.46.255126
9548.167.47.0/2548.167.47.1 to 48.167.47.12648.167.47.127126
9648.167.47.128/2548.167.47.129 to 48.167.47.25448.167.47.255126
9748.167.48.0/2548.167.48.1 to 48.167.48.12648.167.48.127126
9848.167.48.128/2548.167.48.129 to 48.167.48.25448.167.48.255126
9948.167.49.0/2548.167.49.1 to 48.167.49.12648.167.49.127126
10048.167.49.128/2548.167.49.129 to 48.167.49.25448.167.49.255126
10148.167.50.0/2548.167.50.1 to 48.167.50.12648.167.50.127126
10248.167.50.128/2548.167.50.129 to 48.167.50.25448.167.50.255126
10348.167.51.0/2548.167.51.1 to 48.167.51.12648.167.51.127126
10448.167.51.128/2548.167.51.129 to 48.167.51.25448.167.51.255126
10548.167.52.0/2548.167.52.1 to 48.167.52.12648.167.52.127126
10648.167.52.128/2548.167.52.129 to 48.167.52.25448.167.52.255126
10748.167.53.0/2548.167.53.1 to 48.167.53.12648.167.53.127126
10848.167.53.128/2548.167.53.129 to 48.167.53.25448.167.53.255126
10948.167.54.0/2548.167.54.1 to 48.167.54.12648.167.54.127126
11048.167.54.128/2548.167.54.129 to 48.167.54.25448.167.54.255126
11148.167.55.0/2548.167.55.1 to 48.167.55.12648.167.55.127126
11248.167.55.128/2548.167.55.129 to 48.167.55.25448.167.55.255126
11348.167.56.0/2548.167.56.1 to 48.167.56.12648.167.56.127126
11448.167.56.128/2548.167.56.129 to 48.167.56.25448.167.56.255126
11548.167.57.0/2548.167.57.1 to 48.167.57.12648.167.57.127126
11648.167.57.128/2548.167.57.129 to 48.167.57.25448.167.57.255126
11748.167.58.0/2548.167.58.1 to 48.167.58.12648.167.58.127126
11848.167.58.128/2548.167.58.129 to 48.167.58.25448.167.58.255126
11948.167.59.0/2548.167.59.1 to 48.167.59.12648.167.59.127126
12048.167.59.128/2548.167.59.129 to 48.167.59.25448.167.59.255126
12148.167.60.0/2548.167.60.1 to 48.167.60.12648.167.60.127126
12248.167.60.128/2548.167.60.129 to 48.167.60.25448.167.60.255126
12348.167.61.0/2548.167.61.1 to 48.167.61.12648.167.61.127126
12448.167.61.128/2548.167.61.129 to 48.167.61.25448.167.61.255126
12548.167.62.0/2548.167.62.1 to 48.167.62.12648.167.62.127126
12648.167.62.128/2548.167.62.129 to 48.167.62.25448.167.62.255126
12748.167.63.0/2548.167.63.1 to 48.167.63.12648.167.63.127126
12848.167.63.128/2548.167.63.129 to 48.167.63.25448.167.63.255126
12948.167.64.0/2548.167.64.1 to 48.167.64.12648.167.64.127126
13048.167.64.128/2548.167.64.129 to 48.167.64.25448.167.64.255126
13148.167.65.0/2548.167.65.1 to 48.167.65.12648.167.65.127126
13248.167.65.128/2548.167.65.129 to 48.167.65.25448.167.65.255126
13348.167.66.0/2548.167.66.1 to 48.167.66.12648.167.66.127126
13448.167.66.128/2548.167.66.129 to 48.167.66.25448.167.66.255126
13548.167.67.0/2548.167.67.1 to 48.167.67.12648.167.67.127126
13648.167.67.128/2548.167.67.129 to 48.167.67.25448.167.67.255126
13748.167.68.0/2548.167.68.1 to 48.167.68.12648.167.68.127126
13848.167.68.128/2548.167.68.129 to 48.167.68.25448.167.68.255126
13948.167.69.0/2548.167.69.1 to 48.167.69.12648.167.69.127126
14048.167.69.128/2548.167.69.129 to 48.167.69.25448.167.69.255126
14148.167.70.0/2548.167.70.1 to 48.167.70.12648.167.70.127126
14248.167.70.128/2548.167.70.129 to 48.167.70.25448.167.70.255126
14348.167.71.0/2548.167.71.1 to 48.167.71.12648.167.71.127126
14448.167.71.128/2548.167.71.129 to 48.167.71.25448.167.71.255126
14548.167.72.0/2548.167.72.1 to 48.167.72.12648.167.72.127126
14648.167.72.128/2548.167.72.129 to 48.167.72.25448.167.72.255126
14748.167.73.0/2548.167.73.1 to 48.167.73.12648.167.73.127126
14848.167.73.128/2548.167.73.129 to 48.167.73.25448.167.73.255126
14948.167.74.0/2548.167.74.1 to 48.167.74.12648.167.74.127126
15048.167.74.128/2548.167.74.129 to 48.167.74.25448.167.74.255126
15148.167.75.0/2548.167.75.1 to 48.167.75.12648.167.75.127126
15248.167.75.128/2548.167.75.129 to 48.167.75.25448.167.75.255126
15348.167.76.0/2548.167.76.1 to 48.167.76.12648.167.76.127126
15448.167.76.128/2548.167.76.129 to 48.167.76.25448.167.76.255126
15548.167.77.0/2548.167.77.1 to 48.167.77.12648.167.77.127126
15648.167.77.128/2548.167.77.129 to 48.167.77.25448.167.77.255126
15748.167.78.0/2548.167.78.1 to 48.167.78.12648.167.78.127126
15848.167.78.128/2548.167.78.129 to 48.167.78.25448.167.78.255126
15948.167.79.0/2548.167.79.1 to 48.167.79.12648.167.79.127126
16048.167.79.128/2548.167.79.129 to 48.167.79.25448.167.79.255126
16148.167.80.0/2548.167.80.1 to 48.167.80.12648.167.80.127126
16248.167.80.128/2548.167.80.129 to 48.167.80.25448.167.80.255126
16348.167.81.0/2548.167.81.1 to 48.167.81.12648.167.81.127126
16448.167.81.128/2548.167.81.129 to 48.167.81.25448.167.81.255126
16548.167.82.0/2548.167.82.1 to 48.167.82.12648.167.82.127126
16648.167.82.128/2548.167.82.129 to 48.167.82.25448.167.82.255126
16748.167.83.0/2548.167.83.1 to 48.167.83.12648.167.83.127126
16848.167.83.128/2548.167.83.129 to 48.167.83.25448.167.83.255126
16948.167.84.0/2548.167.84.1 to 48.167.84.12648.167.84.127126
17048.167.84.128/2548.167.84.129 to 48.167.84.25448.167.84.255126
17148.167.85.0/2548.167.85.1 to 48.167.85.12648.167.85.127126
17248.167.85.128/2548.167.85.129 to 48.167.85.25448.167.85.255126
17348.167.86.0/2548.167.86.1 to 48.167.86.12648.167.86.127126
17448.167.86.128/2548.167.86.129 to 48.167.86.25448.167.86.255126
17548.167.87.0/2548.167.87.1 to 48.167.87.12648.167.87.127126
17648.167.87.128/2548.167.87.129 to 48.167.87.25448.167.87.255126
17748.167.88.0/2548.167.88.1 to 48.167.88.12648.167.88.127126
17848.167.88.128/2548.167.88.129 to 48.167.88.25448.167.88.255126
17948.167.89.0/2548.167.89.1 to 48.167.89.12648.167.89.127126
18048.167.89.128/2548.167.89.129 to 48.167.89.25448.167.89.255126
18148.167.90.0/2548.167.90.1 to 48.167.90.12648.167.90.127126
18248.167.90.128/2548.167.90.129 to 48.167.90.25448.167.90.255126
18348.167.91.0/2548.167.91.1 to 48.167.91.12648.167.91.127126
18448.167.91.128/2548.167.91.129 to 48.167.91.25448.167.91.255126
18548.167.92.0/2548.167.92.1 to 48.167.92.12648.167.92.127126
18648.167.92.128/2548.167.92.129 to 48.167.92.25448.167.92.255126
18748.167.93.0/2548.167.93.1 to 48.167.93.12648.167.93.127126
18848.167.93.128/2548.167.93.129 to 48.167.93.25448.167.93.255126
18948.167.94.0/2548.167.94.1 to 48.167.94.12648.167.94.127126
19048.167.94.128/2548.167.94.129 to 48.167.94.25448.167.94.255126
19148.167.95.0/2548.167.95.1 to 48.167.95.12648.167.95.127126
19248.167.95.128/2548.167.95.129 to 48.167.95.25448.167.95.255126
19348.167.96.0/2548.167.96.1 to 48.167.96.12648.167.96.127126
19448.167.96.128/2548.167.96.129 to 48.167.96.25448.167.96.255126
19548.167.97.0/2548.167.97.1 to 48.167.97.12648.167.97.127126
19648.167.97.128/2548.167.97.129 to 48.167.97.25448.167.97.255126
19748.167.98.0/2548.167.98.1 to 48.167.98.12648.167.98.127126
19848.167.98.128/2548.167.98.129 to 48.167.98.25448.167.98.255126
19948.167.99.0/2548.167.99.1 to 48.167.99.12648.167.99.127126
20048.167.99.128/2548.167.99.129 to 48.167.99.25448.167.99.255126
20148.167.100.0/2548.167.100.1 to 48.167.100.12648.167.100.127126
20248.167.100.128/2548.167.100.129 to 48.167.100.25448.167.100.255126
20348.167.101.0/2548.167.101.1 to 48.167.101.12648.167.101.127126
20448.167.101.128/2548.167.101.129 to 48.167.101.25448.167.101.255126
20548.167.102.0/2548.167.102.1 to 48.167.102.12648.167.102.127126
20648.167.102.128/2548.167.102.129 to 48.167.102.25448.167.102.255126
20748.167.103.0/2548.167.103.1 to 48.167.103.12648.167.103.127126
20848.167.103.128/2548.167.103.129 to 48.167.103.25448.167.103.255126
20948.167.104.0/2548.167.104.1 to 48.167.104.12648.167.104.127126
21048.167.104.128/2548.167.104.129 to 48.167.104.25448.167.104.255126
21148.167.105.0/2548.167.105.1 to 48.167.105.12648.167.105.127126
21248.167.105.128/2548.167.105.129 to 48.167.105.25448.167.105.255126
21348.167.106.0/2548.167.106.1 to 48.167.106.12648.167.106.127126
21448.167.106.128/2548.167.106.129 to 48.167.106.25448.167.106.255126
21548.167.107.0/2548.167.107.1 to 48.167.107.12648.167.107.127126
21648.167.107.128/2548.167.107.129 to 48.167.107.25448.167.107.255126
21748.167.108.0/2548.167.108.1 to 48.167.108.12648.167.108.127126
21848.167.108.128/2548.167.108.129 to 48.167.108.25448.167.108.255126
21948.167.109.0/2548.167.109.1 to 48.167.109.12648.167.109.127126
22048.167.109.128/2548.167.109.129 to 48.167.109.25448.167.109.255126
22148.167.110.0/2548.167.110.1 to 48.167.110.12648.167.110.127126
22248.167.110.128/2548.167.110.129 to 48.167.110.25448.167.110.255126
22348.167.111.0/2548.167.111.1 to 48.167.111.12648.167.111.127126
22448.167.111.128/2548.167.111.129 to 48.167.111.25448.167.111.255126
22548.167.112.0/2548.167.112.1 to 48.167.112.12648.167.112.127126
22648.167.112.128/2548.167.112.129 to 48.167.112.25448.167.112.255126
22748.167.113.0/2548.167.113.1 to 48.167.113.12648.167.113.127126
22848.167.113.128/2548.167.113.129 to 48.167.113.25448.167.113.255126
22948.167.114.0/2548.167.114.1 to 48.167.114.12648.167.114.127126
23048.167.114.128/2548.167.114.129 to 48.167.114.25448.167.114.255126
23148.167.115.0/2548.167.115.1 to 48.167.115.12648.167.115.127126
23248.167.115.128/2548.167.115.129 to 48.167.115.25448.167.115.255126
23348.167.116.0/2548.167.116.1 to 48.167.116.12648.167.116.127126
23448.167.116.128/2548.167.116.129 to 48.167.116.25448.167.116.255126
23548.167.117.0/2548.167.117.1 to 48.167.117.12648.167.117.127126
23648.167.117.128/2548.167.117.129 to 48.167.117.25448.167.117.255126
23748.167.118.0/2548.167.118.1 to 48.167.118.12648.167.118.127126
23848.167.118.128/2548.167.118.129 to 48.167.118.25448.167.118.255126
23948.167.119.0/2548.167.119.1 to 48.167.119.12648.167.119.127126
24048.167.119.128/2548.167.119.129 to 48.167.119.25448.167.119.255126
24148.167.120.0/2548.167.120.1 to 48.167.120.12648.167.120.127126
24248.167.120.128/2548.167.120.129 to 48.167.120.25448.167.120.255126
24348.167.121.0/2548.167.121.1 to 48.167.121.12648.167.121.127126
24448.167.121.128/2548.167.121.129 to 48.167.121.25448.167.121.255126
24548.167.122.0/2548.167.122.1 to 48.167.122.12648.167.122.127126
24648.167.122.128/2548.167.122.129 to 48.167.122.25448.167.122.255126
24748.167.123.0/2548.167.123.1 to 48.167.123.12648.167.123.127126
24848.167.123.128/2548.167.123.129 to 48.167.123.25448.167.123.255126
24948.167.124.0/2548.167.124.1 to 48.167.124.12648.167.124.127126
25048.167.124.128/2548.167.124.129 to 48.167.124.25448.167.124.255126
25148.167.125.0/2548.167.125.1 to 48.167.125.12648.167.125.127126
25248.167.125.128/2548.167.125.129 to 48.167.125.25448.167.125.255126
25348.167.126.0/2548.167.126.1 to 48.167.126.12648.167.126.127126
25448.167.126.128/2548.167.126.129 to 48.167.126.25448.167.126.255126
25548.167.127.0/2548.167.127.1 to 48.167.127.12648.167.127.127126
25648.167.127.128/2548.167.127.129 to 48.167.127.25448.167.127.255126

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.