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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.

Network97.0.0.0/8
Usable hosts16,777,214
Subnet mask255.0.0.0
Addresses16,777,216
Network address
97.0.0.0
Broadcast address
97.255.255.255
First usable
97.0.0.1
Last usable
97.255.255.254
Usable hosts
16,777,214 (16,777,216 less the network and broadcast addresses)
Subnet mask
255.0.0.0
Wildcard mask
0.255.255.255 (Cisco ACLs, OSPF)
Prefix length
/8
Type
Public public
Old class
A (default /8)
As numbers
Hex 61000000 · Integer 1627389952 to 1644167167
Reverse DNS zone
97.in-addr.arpa
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address01100001..00000000.00000000.0000000097.0.0.0
Subnet mask11111111..00000000.00000000.00000000255.0.0.0
Network01100001..00000000.00000000.0000000097.0.0.0
Broadcast01100001..11111111.11111111.1111111197.255.255.255
Split into smaller subnets/17
/9 (2)/10 (4)/11 (8)/12 (16)/13 (32)/14 (64)/15 (128)/16 (256)/17 (512)/18 (1,024)/19 (2,048)/20 (4,096)

97.0.0.0/8 makes 512 subnets of /17; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
197.0.0.0/1797.0.0.1 to 97.0.127.25497.0.127.25532,766
297.0.128.0/1797.0.128.1 to 97.0.255.25497.0.255.25532,766
397.1.0.0/1797.1.0.1 to 97.1.127.25497.1.127.25532,766
497.1.128.0/1797.1.128.1 to 97.1.255.25497.1.255.25532,766
597.2.0.0/1797.2.0.1 to 97.2.127.25497.2.127.25532,766
697.2.128.0/1797.2.128.1 to 97.2.255.25497.2.255.25532,766
797.3.0.0/1797.3.0.1 to 97.3.127.25497.3.127.25532,766
897.3.128.0/1797.3.128.1 to 97.3.255.25497.3.255.25532,766
997.4.0.0/1797.4.0.1 to 97.4.127.25497.4.127.25532,766
1097.4.128.0/1797.4.128.1 to 97.4.255.25497.4.255.25532,766
1197.5.0.0/1797.5.0.1 to 97.5.127.25497.5.127.25532,766
1297.5.128.0/1797.5.128.1 to 97.5.255.25497.5.255.25532,766
1397.6.0.0/1797.6.0.1 to 97.6.127.25497.6.127.25532,766
1497.6.128.0/1797.6.128.1 to 97.6.255.25497.6.255.25532,766
1597.7.0.0/1797.7.0.1 to 97.7.127.25497.7.127.25532,766
1697.7.128.0/1797.7.128.1 to 97.7.255.25497.7.255.25532,766
1797.8.0.0/1797.8.0.1 to 97.8.127.25497.8.127.25532,766
1897.8.128.0/1797.8.128.1 to 97.8.255.25497.8.255.25532,766
1997.9.0.0/1797.9.0.1 to 97.9.127.25497.9.127.25532,766
2097.9.128.0/1797.9.128.1 to 97.9.255.25497.9.255.25532,766
2197.10.0.0/1797.10.0.1 to 97.10.127.25497.10.127.25532,766
2297.10.128.0/1797.10.128.1 to 97.10.255.25497.10.255.25532,766
2397.11.0.0/1797.11.0.1 to 97.11.127.25497.11.127.25532,766
2497.11.128.0/1797.11.128.1 to 97.11.255.25497.11.255.25532,766
2597.12.0.0/1797.12.0.1 to 97.12.127.25497.12.127.25532,766
2697.12.128.0/1797.12.128.1 to 97.12.255.25497.12.255.25532,766
2797.13.0.0/1797.13.0.1 to 97.13.127.25497.13.127.25532,766
2897.13.128.0/1797.13.128.1 to 97.13.255.25497.13.255.25532,766
2997.14.0.0/1797.14.0.1 to 97.14.127.25497.14.127.25532,766
3097.14.128.0/1797.14.128.1 to 97.14.255.25497.14.255.25532,766
3197.15.0.0/1797.15.0.1 to 97.15.127.25497.15.127.25532,766
3297.15.128.0/1797.15.128.1 to 97.15.255.25497.15.255.25532,766
3397.16.0.0/1797.16.0.1 to 97.16.127.25497.16.127.25532,766
3497.16.128.0/1797.16.128.1 to 97.16.255.25497.16.255.25532,766
3597.17.0.0/1797.17.0.1 to 97.17.127.25497.17.127.25532,766
3697.17.128.0/1797.17.128.1 to 97.17.255.25497.17.255.25532,766
3797.18.0.0/1797.18.0.1 to 97.18.127.25497.18.127.25532,766
3897.18.128.0/1797.18.128.1 to 97.18.255.25497.18.255.25532,766
3997.19.0.0/1797.19.0.1 to 97.19.127.25497.19.127.25532,766
4097.19.128.0/1797.19.128.1 to 97.19.255.25497.19.255.25532,766
4197.20.0.0/1797.20.0.1 to 97.20.127.25497.20.127.25532,766
4297.20.128.0/1797.20.128.1 to 97.20.255.25497.20.255.25532,766
4397.21.0.0/1797.21.0.1 to 97.21.127.25497.21.127.25532,766
4497.21.128.0/1797.21.128.1 to 97.21.255.25497.21.255.25532,766
4597.22.0.0/1797.22.0.1 to 97.22.127.25497.22.127.25532,766
4697.22.128.0/1797.22.128.1 to 97.22.255.25497.22.255.25532,766
4797.23.0.0/1797.23.0.1 to 97.23.127.25497.23.127.25532,766
4897.23.128.0/1797.23.128.1 to 97.23.255.25497.23.255.25532,766
4997.24.0.0/1797.24.0.1 to 97.24.127.25497.24.127.25532,766
5097.24.128.0/1797.24.128.1 to 97.24.255.25497.24.255.25532,766
5197.25.0.0/1797.25.0.1 to 97.25.127.25497.25.127.25532,766
5297.25.128.0/1797.25.128.1 to 97.25.255.25497.25.255.25532,766
5397.26.0.0/1797.26.0.1 to 97.26.127.25497.26.127.25532,766
5497.26.128.0/1797.26.128.1 to 97.26.255.25497.26.255.25532,766
5597.27.0.0/1797.27.0.1 to 97.27.127.25497.27.127.25532,766
5697.27.128.0/1797.27.128.1 to 97.27.255.25497.27.255.25532,766
5797.28.0.0/1797.28.0.1 to 97.28.127.25497.28.127.25532,766
5897.28.128.0/1797.28.128.1 to 97.28.255.25497.28.255.25532,766
5997.29.0.0/1797.29.0.1 to 97.29.127.25497.29.127.25532,766
6097.29.128.0/1797.29.128.1 to 97.29.255.25497.29.255.25532,766
6197.30.0.0/1797.30.0.1 to 97.30.127.25497.30.127.25532,766
6297.30.128.0/1797.30.128.1 to 97.30.255.25497.30.255.25532,766
6397.31.0.0/1797.31.0.1 to 97.31.127.25497.31.127.25532,766
6497.31.128.0/1797.31.128.1 to 97.31.255.25497.31.255.25532,766
6597.32.0.0/1797.32.0.1 to 97.32.127.25497.32.127.25532,766
6697.32.128.0/1797.32.128.1 to 97.32.255.25497.32.255.25532,766
6797.33.0.0/1797.33.0.1 to 97.33.127.25497.33.127.25532,766
6897.33.128.0/1797.33.128.1 to 97.33.255.25497.33.255.25532,766
6997.34.0.0/1797.34.0.1 to 97.34.127.25497.34.127.25532,766
7097.34.128.0/1797.34.128.1 to 97.34.255.25497.34.255.25532,766
7197.35.0.0/1797.35.0.1 to 97.35.127.25497.35.127.25532,766
7297.35.128.0/1797.35.128.1 to 97.35.255.25497.35.255.25532,766
7397.36.0.0/1797.36.0.1 to 97.36.127.25497.36.127.25532,766
7497.36.128.0/1797.36.128.1 to 97.36.255.25497.36.255.25532,766
7597.37.0.0/1797.37.0.1 to 97.37.127.25497.37.127.25532,766
7697.37.128.0/1797.37.128.1 to 97.37.255.25497.37.255.25532,766
7797.38.0.0/1797.38.0.1 to 97.38.127.25497.38.127.25532,766
7897.38.128.0/1797.38.128.1 to 97.38.255.25497.38.255.25532,766
7997.39.0.0/1797.39.0.1 to 97.39.127.25497.39.127.25532,766
8097.39.128.0/1797.39.128.1 to 97.39.255.25497.39.255.25532,766
8197.40.0.0/1797.40.0.1 to 97.40.127.25497.40.127.25532,766
8297.40.128.0/1797.40.128.1 to 97.40.255.25497.40.255.25532,766
8397.41.0.0/1797.41.0.1 to 97.41.127.25497.41.127.25532,766
8497.41.128.0/1797.41.128.1 to 97.41.255.25497.41.255.25532,766
8597.42.0.0/1797.42.0.1 to 97.42.127.25497.42.127.25532,766
8697.42.128.0/1797.42.128.1 to 97.42.255.25497.42.255.25532,766
8797.43.0.0/1797.43.0.1 to 97.43.127.25497.43.127.25532,766
8897.43.128.0/1797.43.128.1 to 97.43.255.25497.43.255.25532,766
8997.44.0.0/1797.44.0.1 to 97.44.127.25497.44.127.25532,766
9097.44.128.0/1797.44.128.1 to 97.44.255.25497.44.255.25532,766
9197.45.0.0/1797.45.0.1 to 97.45.127.25497.45.127.25532,766
9297.45.128.0/1797.45.128.1 to 97.45.255.25497.45.255.25532,766
9397.46.0.0/1797.46.0.1 to 97.46.127.25497.46.127.25532,766
9497.46.128.0/1797.46.128.1 to 97.46.255.25497.46.255.25532,766
9597.47.0.0/1797.47.0.1 to 97.47.127.25497.47.127.25532,766
9697.47.128.0/1797.47.128.1 to 97.47.255.25497.47.255.25532,766
9797.48.0.0/1797.48.0.1 to 97.48.127.25497.48.127.25532,766
9897.48.128.0/1797.48.128.1 to 97.48.255.25497.48.255.25532,766
9997.49.0.0/1797.49.0.1 to 97.49.127.25497.49.127.25532,766
10097.49.128.0/1797.49.128.1 to 97.49.255.25497.49.255.25532,766
10197.50.0.0/1797.50.0.1 to 97.50.127.25497.50.127.25532,766
10297.50.128.0/1797.50.128.1 to 97.50.255.25497.50.255.25532,766
10397.51.0.0/1797.51.0.1 to 97.51.127.25497.51.127.25532,766
10497.51.128.0/1797.51.128.1 to 97.51.255.25497.51.255.25532,766
10597.52.0.0/1797.52.0.1 to 97.52.127.25497.52.127.25532,766
10697.52.128.0/1797.52.128.1 to 97.52.255.25497.52.255.25532,766
10797.53.0.0/1797.53.0.1 to 97.53.127.25497.53.127.25532,766
10897.53.128.0/1797.53.128.1 to 97.53.255.25497.53.255.25532,766
10997.54.0.0/1797.54.0.1 to 97.54.127.25497.54.127.25532,766
11097.54.128.0/1797.54.128.1 to 97.54.255.25497.54.255.25532,766
11197.55.0.0/1797.55.0.1 to 97.55.127.25497.55.127.25532,766
11297.55.128.0/1797.55.128.1 to 97.55.255.25497.55.255.25532,766
11397.56.0.0/1797.56.0.1 to 97.56.127.25497.56.127.25532,766
11497.56.128.0/1797.56.128.1 to 97.56.255.25497.56.255.25532,766
11597.57.0.0/1797.57.0.1 to 97.57.127.25497.57.127.25532,766
11697.57.128.0/1797.57.128.1 to 97.57.255.25497.57.255.25532,766
11797.58.0.0/1797.58.0.1 to 97.58.127.25497.58.127.25532,766
11897.58.128.0/1797.58.128.1 to 97.58.255.25497.58.255.25532,766
11997.59.0.0/1797.59.0.1 to 97.59.127.25497.59.127.25532,766
12097.59.128.0/1797.59.128.1 to 97.59.255.25497.59.255.25532,766
12197.60.0.0/1797.60.0.1 to 97.60.127.25497.60.127.25532,766
12297.60.128.0/1797.60.128.1 to 97.60.255.25497.60.255.25532,766
12397.61.0.0/1797.61.0.1 to 97.61.127.25497.61.127.25532,766
12497.61.128.0/1797.61.128.1 to 97.61.255.25497.61.255.25532,766
12597.62.0.0/1797.62.0.1 to 97.62.127.25497.62.127.25532,766
12697.62.128.0/1797.62.128.1 to 97.62.255.25497.62.255.25532,766
12797.63.0.0/1797.63.0.1 to 97.63.127.25497.63.127.25532,766
12897.63.128.0/1797.63.128.1 to 97.63.255.25497.63.255.25532,766
12997.64.0.0/1797.64.0.1 to 97.64.127.25497.64.127.25532,766
13097.64.128.0/1797.64.128.1 to 97.64.255.25497.64.255.25532,766
13197.65.0.0/1797.65.0.1 to 97.65.127.25497.65.127.25532,766
13297.65.128.0/1797.65.128.1 to 97.65.255.25497.65.255.25532,766
13397.66.0.0/1797.66.0.1 to 97.66.127.25497.66.127.25532,766
13497.66.128.0/1797.66.128.1 to 97.66.255.25497.66.255.25532,766
13597.67.0.0/1797.67.0.1 to 97.67.127.25497.67.127.25532,766
13697.67.128.0/1797.67.128.1 to 97.67.255.25497.67.255.25532,766
13797.68.0.0/1797.68.0.1 to 97.68.127.25497.68.127.25532,766
13897.68.128.0/1797.68.128.1 to 97.68.255.25497.68.255.25532,766
13997.69.0.0/1797.69.0.1 to 97.69.127.25497.69.127.25532,766
14097.69.128.0/1797.69.128.1 to 97.69.255.25497.69.255.25532,766
14197.70.0.0/1797.70.0.1 to 97.70.127.25497.70.127.25532,766
14297.70.128.0/1797.70.128.1 to 97.70.255.25497.70.255.25532,766
14397.71.0.0/1797.71.0.1 to 97.71.127.25497.71.127.25532,766
14497.71.128.0/1797.71.128.1 to 97.71.255.25497.71.255.25532,766
14597.72.0.0/1797.72.0.1 to 97.72.127.25497.72.127.25532,766
14697.72.128.0/1797.72.128.1 to 97.72.255.25497.72.255.25532,766
14797.73.0.0/1797.73.0.1 to 97.73.127.25497.73.127.25532,766
14897.73.128.0/1797.73.128.1 to 97.73.255.25497.73.255.25532,766
14997.74.0.0/1797.74.0.1 to 97.74.127.25497.74.127.25532,766
15097.74.128.0/1797.74.128.1 to 97.74.255.25497.74.255.25532,766
15197.75.0.0/1797.75.0.1 to 97.75.127.25497.75.127.25532,766
15297.75.128.0/1797.75.128.1 to 97.75.255.25497.75.255.25532,766
15397.76.0.0/1797.76.0.1 to 97.76.127.25497.76.127.25532,766
15497.76.128.0/1797.76.128.1 to 97.76.255.25497.76.255.25532,766
15597.77.0.0/1797.77.0.1 to 97.77.127.25497.77.127.25532,766
15697.77.128.0/1797.77.128.1 to 97.77.255.25497.77.255.25532,766
15797.78.0.0/1797.78.0.1 to 97.78.127.25497.78.127.25532,766
15897.78.128.0/1797.78.128.1 to 97.78.255.25497.78.255.25532,766
15997.79.0.0/1797.79.0.1 to 97.79.127.25497.79.127.25532,766
16097.79.128.0/1797.79.128.1 to 97.79.255.25497.79.255.25532,766
16197.80.0.0/1797.80.0.1 to 97.80.127.25497.80.127.25532,766
16297.80.128.0/1797.80.128.1 to 97.80.255.25497.80.255.25532,766
16397.81.0.0/1797.81.0.1 to 97.81.127.25497.81.127.25532,766
16497.81.128.0/1797.81.128.1 to 97.81.255.25497.81.255.25532,766
16597.82.0.0/1797.82.0.1 to 97.82.127.25497.82.127.25532,766
16697.82.128.0/1797.82.128.1 to 97.82.255.25497.82.255.25532,766
16797.83.0.0/1797.83.0.1 to 97.83.127.25497.83.127.25532,766
16897.83.128.0/1797.83.128.1 to 97.83.255.25497.83.255.25532,766
16997.84.0.0/1797.84.0.1 to 97.84.127.25497.84.127.25532,766
17097.84.128.0/1797.84.128.1 to 97.84.255.25497.84.255.25532,766
17197.85.0.0/1797.85.0.1 to 97.85.127.25497.85.127.25532,766
17297.85.128.0/1797.85.128.1 to 97.85.255.25497.85.255.25532,766
17397.86.0.0/1797.86.0.1 to 97.86.127.25497.86.127.25532,766
17497.86.128.0/1797.86.128.1 to 97.86.255.25497.86.255.25532,766
17597.87.0.0/1797.87.0.1 to 97.87.127.25497.87.127.25532,766
17697.87.128.0/1797.87.128.1 to 97.87.255.25497.87.255.25532,766
17797.88.0.0/1797.88.0.1 to 97.88.127.25497.88.127.25532,766
17897.88.128.0/1797.88.128.1 to 97.88.255.25497.88.255.25532,766
17997.89.0.0/1797.89.0.1 to 97.89.127.25497.89.127.25532,766
18097.89.128.0/1797.89.128.1 to 97.89.255.25497.89.255.25532,766
18197.90.0.0/1797.90.0.1 to 97.90.127.25497.90.127.25532,766
18297.90.128.0/1797.90.128.1 to 97.90.255.25497.90.255.25532,766
18397.91.0.0/1797.91.0.1 to 97.91.127.25497.91.127.25532,766
18497.91.128.0/1797.91.128.1 to 97.91.255.25497.91.255.25532,766
18597.92.0.0/1797.92.0.1 to 97.92.127.25497.92.127.25532,766
18697.92.128.0/1797.92.128.1 to 97.92.255.25497.92.255.25532,766
18797.93.0.0/1797.93.0.1 to 97.93.127.25497.93.127.25532,766
18897.93.128.0/1797.93.128.1 to 97.93.255.25497.93.255.25532,766
18997.94.0.0/1797.94.0.1 to 97.94.127.25497.94.127.25532,766
19097.94.128.0/1797.94.128.1 to 97.94.255.25497.94.255.25532,766
19197.95.0.0/1797.95.0.1 to 97.95.127.25497.95.127.25532,766
19297.95.128.0/1797.95.128.1 to 97.95.255.25497.95.255.25532,766
19397.96.0.0/1797.96.0.1 to 97.96.127.25497.96.127.25532,766
19497.96.128.0/1797.96.128.1 to 97.96.255.25497.96.255.25532,766
19597.97.0.0/1797.97.0.1 to 97.97.127.25497.97.127.25532,766
19697.97.128.0/1797.97.128.1 to 97.97.255.25497.97.255.25532,766
19797.98.0.0/1797.98.0.1 to 97.98.127.25497.98.127.25532,766
19897.98.128.0/1797.98.128.1 to 97.98.255.25497.98.255.25532,766
19997.99.0.0/1797.99.0.1 to 97.99.127.25497.99.127.25532,766
20097.99.128.0/1797.99.128.1 to 97.99.255.25497.99.255.25532,766
20197.100.0.0/1797.100.0.1 to 97.100.127.25497.100.127.25532,766
20297.100.128.0/1797.100.128.1 to 97.100.255.25497.100.255.25532,766
20397.101.0.0/1797.101.0.1 to 97.101.127.25497.101.127.25532,766
20497.101.128.0/1797.101.128.1 to 97.101.255.25497.101.255.25532,766
20597.102.0.0/1797.102.0.1 to 97.102.127.25497.102.127.25532,766
20697.102.128.0/1797.102.128.1 to 97.102.255.25497.102.255.25532,766
20797.103.0.0/1797.103.0.1 to 97.103.127.25497.103.127.25532,766
20897.103.128.0/1797.103.128.1 to 97.103.255.25497.103.255.25532,766
20997.104.0.0/1797.104.0.1 to 97.104.127.25497.104.127.25532,766
21097.104.128.0/1797.104.128.1 to 97.104.255.25497.104.255.25532,766
21197.105.0.0/1797.105.0.1 to 97.105.127.25497.105.127.25532,766
21297.105.128.0/1797.105.128.1 to 97.105.255.25497.105.255.25532,766
21397.106.0.0/1797.106.0.1 to 97.106.127.25497.106.127.25532,766
21497.106.128.0/1797.106.128.1 to 97.106.255.25497.106.255.25532,766
21597.107.0.0/1797.107.0.1 to 97.107.127.25497.107.127.25532,766
21697.107.128.0/1797.107.128.1 to 97.107.255.25497.107.255.25532,766
21797.108.0.0/1797.108.0.1 to 97.108.127.25497.108.127.25532,766
21897.108.128.0/1797.108.128.1 to 97.108.255.25497.108.255.25532,766
21997.109.0.0/1797.109.0.1 to 97.109.127.25497.109.127.25532,766
22097.109.128.0/1797.109.128.1 to 97.109.255.25497.109.255.25532,766
22197.110.0.0/1797.110.0.1 to 97.110.127.25497.110.127.25532,766
22297.110.128.0/1797.110.128.1 to 97.110.255.25497.110.255.25532,766
22397.111.0.0/1797.111.0.1 to 97.111.127.25497.111.127.25532,766
22497.111.128.0/1797.111.128.1 to 97.111.255.25497.111.255.25532,766
22597.112.0.0/1797.112.0.1 to 97.112.127.25497.112.127.25532,766
22697.112.128.0/1797.112.128.1 to 97.112.255.25497.112.255.25532,766
22797.113.0.0/1797.113.0.1 to 97.113.127.25497.113.127.25532,766
22897.113.128.0/1797.113.128.1 to 97.113.255.25497.113.255.25532,766
22997.114.0.0/1797.114.0.1 to 97.114.127.25497.114.127.25532,766
23097.114.128.0/1797.114.128.1 to 97.114.255.25497.114.255.25532,766
23197.115.0.0/1797.115.0.1 to 97.115.127.25497.115.127.25532,766
23297.115.128.0/1797.115.128.1 to 97.115.255.25497.115.255.25532,766
23397.116.0.0/1797.116.0.1 to 97.116.127.25497.116.127.25532,766
23497.116.128.0/1797.116.128.1 to 97.116.255.25497.116.255.25532,766
23597.117.0.0/1797.117.0.1 to 97.117.127.25497.117.127.25532,766
23697.117.128.0/1797.117.128.1 to 97.117.255.25497.117.255.25532,766
23797.118.0.0/1797.118.0.1 to 97.118.127.25497.118.127.25532,766
23897.118.128.0/1797.118.128.1 to 97.118.255.25497.118.255.25532,766
23997.119.0.0/1797.119.0.1 to 97.119.127.25497.119.127.25532,766
24097.119.128.0/1797.119.128.1 to 97.119.255.25497.119.255.25532,766
24197.120.0.0/1797.120.0.1 to 97.120.127.25497.120.127.25532,766
24297.120.128.0/1797.120.128.1 to 97.120.255.25497.120.255.25532,766
24397.121.0.0/1797.121.0.1 to 97.121.127.25497.121.127.25532,766
24497.121.128.0/1797.121.128.1 to 97.121.255.25497.121.255.25532,766
24597.122.0.0/1797.122.0.1 to 97.122.127.25497.122.127.25532,766
24697.122.128.0/1797.122.128.1 to 97.122.255.25497.122.255.25532,766
24797.123.0.0/1797.123.0.1 to 97.123.127.25497.123.127.25532,766
24897.123.128.0/1797.123.128.1 to 97.123.255.25497.123.255.25532,766
24997.124.0.0/1797.124.0.1 to 97.124.127.25497.124.127.25532,766
25097.124.128.0/1797.124.128.1 to 97.124.255.25497.124.255.25532,766
25197.125.0.0/1797.125.0.1 to 97.125.127.25497.125.127.25532,766
25297.125.128.0/1797.125.128.1 to 97.125.255.25497.125.255.25532,766
25397.126.0.0/1797.126.0.1 to 97.126.127.25497.126.127.25532,766
25497.126.128.0/1797.126.128.1 to 97.126.255.25497.126.255.25532,766
25597.127.0.0/1797.127.0.1 to 97.127.127.25497.127.127.25532,766
25697.127.128.0/1797.127.128.1 to 97.127.255.25497.127.255.25532,766

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.