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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.

Network85.0.0.0/8
Usable hosts16,777,214
Subnet mask255.0.0.0
Addresses16,777,216
Network address
85.0.0.0
Broadcast address
85.255.255.255
First usable
85.0.0.1
Last usable
85.255.255.254
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 55000000 · Integer 1426063360 to 1442840575
Reverse DNS zone
85.in-addr.arpa
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address01010101..00000000.00000000.0000000085.0.0.0
Subnet mask11111111..00000000.00000000.00000000255.0.0.0
Network01010101..00000000.00000000.0000000085.0.0.0
Broadcast01010101..11111111.11111111.1111111185.255.255.255
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)

85.0.0.0/8 makes 512 subnets of /17; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
185.0.0.0/1785.0.0.1 to 85.0.127.25485.0.127.25532,766
285.0.128.0/1785.0.128.1 to 85.0.255.25485.0.255.25532,766
385.1.0.0/1785.1.0.1 to 85.1.127.25485.1.127.25532,766
485.1.128.0/1785.1.128.1 to 85.1.255.25485.1.255.25532,766
585.2.0.0/1785.2.0.1 to 85.2.127.25485.2.127.25532,766
685.2.128.0/1785.2.128.1 to 85.2.255.25485.2.255.25532,766
785.3.0.0/1785.3.0.1 to 85.3.127.25485.3.127.25532,766
885.3.128.0/1785.3.128.1 to 85.3.255.25485.3.255.25532,766
985.4.0.0/1785.4.0.1 to 85.4.127.25485.4.127.25532,766
1085.4.128.0/1785.4.128.1 to 85.4.255.25485.4.255.25532,766
1185.5.0.0/1785.5.0.1 to 85.5.127.25485.5.127.25532,766
1285.5.128.0/1785.5.128.1 to 85.5.255.25485.5.255.25532,766
1385.6.0.0/1785.6.0.1 to 85.6.127.25485.6.127.25532,766
1485.6.128.0/1785.6.128.1 to 85.6.255.25485.6.255.25532,766
1585.7.0.0/1785.7.0.1 to 85.7.127.25485.7.127.25532,766
1685.7.128.0/1785.7.128.1 to 85.7.255.25485.7.255.25532,766
1785.8.0.0/1785.8.0.1 to 85.8.127.25485.8.127.25532,766
1885.8.128.0/1785.8.128.1 to 85.8.255.25485.8.255.25532,766
1985.9.0.0/1785.9.0.1 to 85.9.127.25485.9.127.25532,766
2085.9.128.0/1785.9.128.1 to 85.9.255.25485.9.255.25532,766
2185.10.0.0/1785.10.0.1 to 85.10.127.25485.10.127.25532,766
2285.10.128.0/1785.10.128.1 to 85.10.255.25485.10.255.25532,766
2385.11.0.0/1785.11.0.1 to 85.11.127.25485.11.127.25532,766
2485.11.128.0/1785.11.128.1 to 85.11.255.25485.11.255.25532,766
2585.12.0.0/1785.12.0.1 to 85.12.127.25485.12.127.25532,766
2685.12.128.0/1785.12.128.1 to 85.12.255.25485.12.255.25532,766
2785.13.0.0/1785.13.0.1 to 85.13.127.25485.13.127.25532,766
2885.13.128.0/1785.13.128.1 to 85.13.255.25485.13.255.25532,766
2985.14.0.0/1785.14.0.1 to 85.14.127.25485.14.127.25532,766
3085.14.128.0/1785.14.128.1 to 85.14.255.25485.14.255.25532,766
3185.15.0.0/1785.15.0.1 to 85.15.127.25485.15.127.25532,766
3285.15.128.0/1785.15.128.1 to 85.15.255.25485.15.255.25532,766
3385.16.0.0/1785.16.0.1 to 85.16.127.25485.16.127.25532,766
3485.16.128.0/1785.16.128.1 to 85.16.255.25485.16.255.25532,766
3585.17.0.0/1785.17.0.1 to 85.17.127.25485.17.127.25532,766
3685.17.128.0/1785.17.128.1 to 85.17.255.25485.17.255.25532,766
3785.18.0.0/1785.18.0.1 to 85.18.127.25485.18.127.25532,766
3885.18.128.0/1785.18.128.1 to 85.18.255.25485.18.255.25532,766
3985.19.0.0/1785.19.0.1 to 85.19.127.25485.19.127.25532,766
4085.19.128.0/1785.19.128.1 to 85.19.255.25485.19.255.25532,766
4185.20.0.0/1785.20.0.1 to 85.20.127.25485.20.127.25532,766
4285.20.128.0/1785.20.128.1 to 85.20.255.25485.20.255.25532,766
4385.21.0.0/1785.21.0.1 to 85.21.127.25485.21.127.25532,766
4485.21.128.0/1785.21.128.1 to 85.21.255.25485.21.255.25532,766
4585.22.0.0/1785.22.0.1 to 85.22.127.25485.22.127.25532,766
4685.22.128.0/1785.22.128.1 to 85.22.255.25485.22.255.25532,766
4785.23.0.0/1785.23.0.1 to 85.23.127.25485.23.127.25532,766
4885.23.128.0/1785.23.128.1 to 85.23.255.25485.23.255.25532,766
4985.24.0.0/1785.24.0.1 to 85.24.127.25485.24.127.25532,766
5085.24.128.0/1785.24.128.1 to 85.24.255.25485.24.255.25532,766
5185.25.0.0/1785.25.0.1 to 85.25.127.25485.25.127.25532,766
5285.25.128.0/1785.25.128.1 to 85.25.255.25485.25.255.25532,766
5385.26.0.0/1785.26.0.1 to 85.26.127.25485.26.127.25532,766
5485.26.128.0/1785.26.128.1 to 85.26.255.25485.26.255.25532,766
5585.27.0.0/1785.27.0.1 to 85.27.127.25485.27.127.25532,766
5685.27.128.0/1785.27.128.1 to 85.27.255.25485.27.255.25532,766
5785.28.0.0/1785.28.0.1 to 85.28.127.25485.28.127.25532,766
5885.28.128.0/1785.28.128.1 to 85.28.255.25485.28.255.25532,766
5985.29.0.0/1785.29.0.1 to 85.29.127.25485.29.127.25532,766
6085.29.128.0/1785.29.128.1 to 85.29.255.25485.29.255.25532,766
6185.30.0.0/1785.30.0.1 to 85.30.127.25485.30.127.25532,766
6285.30.128.0/1785.30.128.1 to 85.30.255.25485.30.255.25532,766
6385.31.0.0/1785.31.0.1 to 85.31.127.25485.31.127.25532,766
6485.31.128.0/1785.31.128.1 to 85.31.255.25485.31.255.25532,766
6585.32.0.0/1785.32.0.1 to 85.32.127.25485.32.127.25532,766
6685.32.128.0/1785.32.128.1 to 85.32.255.25485.32.255.25532,766
6785.33.0.0/1785.33.0.1 to 85.33.127.25485.33.127.25532,766
6885.33.128.0/1785.33.128.1 to 85.33.255.25485.33.255.25532,766
6985.34.0.0/1785.34.0.1 to 85.34.127.25485.34.127.25532,766
7085.34.128.0/1785.34.128.1 to 85.34.255.25485.34.255.25532,766
7185.35.0.0/1785.35.0.1 to 85.35.127.25485.35.127.25532,766
7285.35.128.0/1785.35.128.1 to 85.35.255.25485.35.255.25532,766
7385.36.0.0/1785.36.0.1 to 85.36.127.25485.36.127.25532,766
7485.36.128.0/1785.36.128.1 to 85.36.255.25485.36.255.25532,766
7585.37.0.0/1785.37.0.1 to 85.37.127.25485.37.127.25532,766
7685.37.128.0/1785.37.128.1 to 85.37.255.25485.37.255.25532,766
7785.38.0.0/1785.38.0.1 to 85.38.127.25485.38.127.25532,766
7885.38.128.0/1785.38.128.1 to 85.38.255.25485.38.255.25532,766
7985.39.0.0/1785.39.0.1 to 85.39.127.25485.39.127.25532,766
8085.39.128.0/1785.39.128.1 to 85.39.255.25485.39.255.25532,766
8185.40.0.0/1785.40.0.1 to 85.40.127.25485.40.127.25532,766
8285.40.128.0/1785.40.128.1 to 85.40.255.25485.40.255.25532,766
8385.41.0.0/1785.41.0.1 to 85.41.127.25485.41.127.25532,766
8485.41.128.0/1785.41.128.1 to 85.41.255.25485.41.255.25532,766
8585.42.0.0/1785.42.0.1 to 85.42.127.25485.42.127.25532,766
8685.42.128.0/1785.42.128.1 to 85.42.255.25485.42.255.25532,766
8785.43.0.0/1785.43.0.1 to 85.43.127.25485.43.127.25532,766
8885.43.128.0/1785.43.128.1 to 85.43.255.25485.43.255.25532,766
8985.44.0.0/1785.44.0.1 to 85.44.127.25485.44.127.25532,766
9085.44.128.0/1785.44.128.1 to 85.44.255.25485.44.255.25532,766
9185.45.0.0/1785.45.0.1 to 85.45.127.25485.45.127.25532,766
9285.45.128.0/1785.45.128.1 to 85.45.255.25485.45.255.25532,766
9385.46.0.0/1785.46.0.1 to 85.46.127.25485.46.127.25532,766
9485.46.128.0/1785.46.128.1 to 85.46.255.25485.46.255.25532,766
9585.47.0.0/1785.47.0.1 to 85.47.127.25485.47.127.25532,766
9685.47.128.0/1785.47.128.1 to 85.47.255.25485.47.255.25532,766
9785.48.0.0/1785.48.0.1 to 85.48.127.25485.48.127.25532,766
9885.48.128.0/1785.48.128.1 to 85.48.255.25485.48.255.25532,766
9985.49.0.0/1785.49.0.1 to 85.49.127.25485.49.127.25532,766
10085.49.128.0/1785.49.128.1 to 85.49.255.25485.49.255.25532,766
10185.50.0.0/1785.50.0.1 to 85.50.127.25485.50.127.25532,766
10285.50.128.0/1785.50.128.1 to 85.50.255.25485.50.255.25532,766
10385.51.0.0/1785.51.0.1 to 85.51.127.25485.51.127.25532,766
10485.51.128.0/1785.51.128.1 to 85.51.255.25485.51.255.25532,766
10585.52.0.0/1785.52.0.1 to 85.52.127.25485.52.127.25532,766
10685.52.128.0/1785.52.128.1 to 85.52.255.25485.52.255.25532,766
10785.53.0.0/1785.53.0.1 to 85.53.127.25485.53.127.25532,766
10885.53.128.0/1785.53.128.1 to 85.53.255.25485.53.255.25532,766
10985.54.0.0/1785.54.0.1 to 85.54.127.25485.54.127.25532,766
11085.54.128.0/1785.54.128.1 to 85.54.255.25485.54.255.25532,766
11185.55.0.0/1785.55.0.1 to 85.55.127.25485.55.127.25532,766
11285.55.128.0/1785.55.128.1 to 85.55.255.25485.55.255.25532,766
11385.56.0.0/1785.56.0.1 to 85.56.127.25485.56.127.25532,766
11485.56.128.0/1785.56.128.1 to 85.56.255.25485.56.255.25532,766
11585.57.0.0/1785.57.0.1 to 85.57.127.25485.57.127.25532,766
11685.57.128.0/1785.57.128.1 to 85.57.255.25485.57.255.25532,766
11785.58.0.0/1785.58.0.1 to 85.58.127.25485.58.127.25532,766
11885.58.128.0/1785.58.128.1 to 85.58.255.25485.58.255.25532,766
11985.59.0.0/1785.59.0.1 to 85.59.127.25485.59.127.25532,766
12085.59.128.0/1785.59.128.1 to 85.59.255.25485.59.255.25532,766
12185.60.0.0/1785.60.0.1 to 85.60.127.25485.60.127.25532,766
12285.60.128.0/1785.60.128.1 to 85.60.255.25485.60.255.25532,766
12385.61.0.0/1785.61.0.1 to 85.61.127.25485.61.127.25532,766
12485.61.128.0/1785.61.128.1 to 85.61.255.25485.61.255.25532,766
12585.62.0.0/1785.62.0.1 to 85.62.127.25485.62.127.25532,766
12685.62.128.0/1785.62.128.1 to 85.62.255.25485.62.255.25532,766
12785.63.0.0/1785.63.0.1 to 85.63.127.25485.63.127.25532,766
12885.63.128.0/1785.63.128.1 to 85.63.255.25485.63.255.25532,766
12985.64.0.0/1785.64.0.1 to 85.64.127.25485.64.127.25532,766
13085.64.128.0/1785.64.128.1 to 85.64.255.25485.64.255.25532,766
13185.65.0.0/1785.65.0.1 to 85.65.127.25485.65.127.25532,766
13285.65.128.0/1785.65.128.1 to 85.65.255.25485.65.255.25532,766
13385.66.0.0/1785.66.0.1 to 85.66.127.25485.66.127.25532,766
13485.66.128.0/1785.66.128.1 to 85.66.255.25485.66.255.25532,766
13585.67.0.0/1785.67.0.1 to 85.67.127.25485.67.127.25532,766
13685.67.128.0/1785.67.128.1 to 85.67.255.25485.67.255.25532,766
13785.68.0.0/1785.68.0.1 to 85.68.127.25485.68.127.25532,766
13885.68.128.0/1785.68.128.1 to 85.68.255.25485.68.255.25532,766
13985.69.0.0/1785.69.0.1 to 85.69.127.25485.69.127.25532,766
14085.69.128.0/1785.69.128.1 to 85.69.255.25485.69.255.25532,766
14185.70.0.0/1785.70.0.1 to 85.70.127.25485.70.127.25532,766
14285.70.128.0/1785.70.128.1 to 85.70.255.25485.70.255.25532,766
14385.71.0.0/1785.71.0.1 to 85.71.127.25485.71.127.25532,766
14485.71.128.0/1785.71.128.1 to 85.71.255.25485.71.255.25532,766
14585.72.0.0/1785.72.0.1 to 85.72.127.25485.72.127.25532,766
14685.72.128.0/1785.72.128.1 to 85.72.255.25485.72.255.25532,766
14785.73.0.0/1785.73.0.1 to 85.73.127.25485.73.127.25532,766
14885.73.128.0/1785.73.128.1 to 85.73.255.25485.73.255.25532,766
14985.74.0.0/1785.74.0.1 to 85.74.127.25485.74.127.25532,766
15085.74.128.0/1785.74.128.1 to 85.74.255.25485.74.255.25532,766
15185.75.0.0/1785.75.0.1 to 85.75.127.25485.75.127.25532,766
15285.75.128.0/1785.75.128.1 to 85.75.255.25485.75.255.25532,766
15385.76.0.0/1785.76.0.1 to 85.76.127.25485.76.127.25532,766
15485.76.128.0/1785.76.128.1 to 85.76.255.25485.76.255.25532,766
15585.77.0.0/1785.77.0.1 to 85.77.127.25485.77.127.25532,766
15685.77.128.0/1785.77.128.1 to 85.77.255.25485.77.255.25532,766
15785.78.0.0/1785.78.0.1 to 85.78.127.25485.78.127.25532,766
15885.78.128.0/1785.78.128.1 to 85.78.255.25485.78.255.25532,766
15985.79.0.0/1785.79.0.1 to 85.79.127.25485.79.127.25532,766
16085.79.128.0/1785.79.128.1 to 85.79.255.25485.79.255.25532,766
16185.80.0.0/1785.80.0.1 to 85.80.127.25485.80.127.25532,766
16285.80.128.0/1785.80.128.1 to 85.80.255.25485.80.255.25532,766
16385.81.0.0/1785.81.0.1 to 85.81.127.25485.81.127.25532,766
16485.81.128.0/1785.81.128.1 to 85.81.255.25485.81.255.25532,766
16585.82.0.0/1785.82.0.1 to 85.82.127.25485.82.127.25532,766
16685.82.128.0/1785.82.128.1 to 85.82.255.25485.82.255.25532,766
16785.83.0.0/1785.83.0.1 to 85.83.127.25485.83.127.25532,766
16885.83.128.0/1785.83.128.1 to 85.83.255.25485.83.255.25532,766
16985.84.0.0/1785.84.0.1 to 85.84.127.25485.84.127.25532,766
17085.84.128.0/1785.84.128.1 to 85.84.255.25485.84.255.25532,766
17185.85.0.0/1785.85.0.1 to 85.85.127.25485.85.127.25532,766
17285.85.128.0/1785.85.128.1 to 85.85.255.25485.85.255.25532,766
17385.86.0.0/1785.86.0.1 to 85.86.127.25485.86.127.25532,766
17485.86.128.0/1785.86.128.1 to 85.86.255.25485.86.255.25532,766
17585.87.0.0/1785.87.0.1 to 85.87.127.25485.87.127.25532,766
17685.87.128.0/1785.87.128.1 to 85.87.255.25485.87.255.25532,766
17785.88.0.0/1785.88.0.1 to 85.88.127.25485.88.127.25532,766
17885.88.128.0/1785.88.128.1 to 85.88.255.25485.88.255.25532,766
17985.89.0.0/1785.89.0.1 to 85.89.127.25485.89.127.25532,766
18085.89.128.0/1785.89.128.1 to 85.89.255.25485.89.255.25532,766
18185.90.0.0/1785.90.0.1 to 85.90.127.25485.90.127.25532,766
18285.90.128.0/1785.90.128.1 to 85.90.255.25485.90.255.25532,766
18385.91.0.0/1785.91.0.1 to 85.91.127.25485.91.127.25532,766
18485.91.128.0/1785.91.128.1 to 85.91.255.25485.91.255.25532,766
18585.92.0.0/1785.92.0.1 to 85.92.127.25485.92.127.25532,766
18685.92.128.0/1785.92.128.1 to 85.92.255.25485.92.255.25532,766
18785.93.0.0/1785.93.0.1 to 85.93.127.25485.93.127.25532,766
18885.93.128.0/1785.93.128.1 to 85.93.255.25485.93.255.25532,766
18985.94.0.0/1785.94.0.1 to 85.94.127.25485.94.127.25532,766
19085.94.128.0/1785.94.128.1 to 85.94.255.25485.94.255.25532,766
19185.95.0.0/1785.95.0.1 to 85.95.127.25485.95.127.25532,766
19285.95.128.0/1785.95.128.1 to 85.95.255.25485.95.255.25532,766
19385.96.0.0/1785.96.0.1 to 85.96.127.25485.96.127.25532,766
19485.96.128.0/1785.96.128.1 to 85.96.255.25485.96.255.25532,766
19585.97.0.0/1785.97.0.1 to 85.97.127.25485.97.127.25532,766
19685.97.128.0/1785.97.128.1 to 85.97.255.25485.97.255.25532,766
19785.98.0.0/1785.98.0.1 to 85.98.127.25485.98.127.25532,766
19885.98.128.0/1785.98.128.1 to 85.98.255.25485.98.255.25532,766
19985.99.0.0/1785.99.0.1 to 85.99.127.25485.99.127.25532,766
20085.99.128.0/1785.99.128.1 to 85.99.255.25485.99.255.25532,766
20185.100.0.0/1785.100.0.1 to 85.100.127.25485.100.127.25532,766
20285.100.128.0/1785.100.128.1 to 85.100.255.25485.100.255.25532,766
20385.101.0.0/1785.101.0.1 to 85.101.127.25485.101.127.25532,766
20485.101.128.0/1785.101.128.1 to 85.101.255.25485.101.255.25532,766
20585.102.0.0/1785.102.0.1 to 85.102.127.25485.102.127.25532,766
20685.102.128.0/1785.102.128.1 to 85.102.255.25485.102.255.25532,766
20785.103.0.0/1785.103.0.1 to 85.103.127.25485.103.127.25532,766
20885.103.128.0/1785.103.128.1 to 85.103.255.25485.103.255.25532,766
20985.104.0.0/1785.104.0.1 to 85.104.127.25485.104.127.25532,766
21085.104.128.0/1785.104.128.1 to 85.104.255.25485.104.255.25532,766
21185.105.0.0/1785.105.0.1 to 85.105.127.25485.105.127.25532,766
21285.105.128.0/1785.105.128.1 to 85.105.255.25485.105.255.25532,766
21385.106.0.0/1785.106.0.1 to 85.106.127.25485.106.127.25532,766
21485.106.128.0/1785.106.128.1 to 85.106.255.25485.106.255.25532,766
21585.107.0.0/1785.107.0.1 to 85.107.127.25485.107.127.25532,766
21685.107.128.0/1785.107.128.1 to 85.107.255.25485.107.255.25532,766
21785.108.0.0/1785.108.0.1 to 85.108.127.25485.108.127.25532,766
21885.108.128.0/1785.108.128.1 to 85.108.255.25485.108.255.25532,766
21985.109.0.0/1785.109.0.1 to 85.109.127.25485.109.127.25532,766
22085.109.128.0/1785.109.128.1 to 85.109.255.25485.109.255.25532,766
22185.110.0.0/1785.110.0.1 to 85.110.127.25485.110.127.25532,766
22285.110.128.0/1785.110.128.1 to 85.110.255.25485.110.255.25532,766
22385.111.0.0/1785.111.0.1 to 85.111.127.25485.111.127.25532,766
22485.111.128.0/1785.111.128.1 to 85.111.255.25485.111.255.25532,766
22585.112.0.0/1785.112.0.1 to 85.112.127.25485.112.127.25532,766
22685.112.128.0/1785.112.128.1 to 85.112.255.25485.112.255.25532,766
22785.113.0.0/1785.113.0.1 to 85.113.127.25485.113.127.25532,766
22885.113.128.0/1785.113.128.1 to 85.113.255.25485.113.255.25532,766
22985.114.0.0/1785.114.0.1 to 85.114.127.25485.114.127.25532,766
23085.114.128.0/1785.114.128.1 to 85.114.255.25485.114.255.25532,766
23185.115.0.0/1785.115.0.1 to 85.115.127.25485.115.127.25532,766
23285.115.128.0/1785.115.128.1 to 85.115.255.25485.115.255.25532,766
23385.116.0.0/1785.116.0.1 to 85.116.127.25485.116.127.25532,766
23485.116.128.0/1785.116.128.1 to 85.116.255.25485.116.255.25532,766
23585.117.0.0/1785.117.0.1 to 85.117.127.25485.117.127.25532,766
23685.117.128.0/1785.117.128.1 to 85.117.255.25485.117.255.25532,766
23785.118.0.0/1785.118.0.1 to 85.118.127.25485.118.127.25532,766
23885.118.128.0/1785.118.128.1 to 85.118.255.25485.118.255.25532,766
23985.119.0.0/1785.119.0.1 to 85.119.127.25485.119.127.25532,766
24085.119.128.0/1785.119.128.1 to 85.119.255.25485.119.255.25532,766
24185.120.0.0/1785.120.0.1 to 85.120.127.25485.120.127.25532,766
24285.120.128.0/1785.120.128.1 to 85.120.255.25485.120.255.25532,766
24385.121.0.0/1785.121.0.1 to 85.121.127.25485.121.127.25532,766
24485.121.128.0/1785.121.128.1 to 85.121.255.25485.121.255.25532,766
24585.122.0.0/1785.122.0.1 to 85.122.127.25485.122.127.25532,766
24685.122.128.0/1785.122.128.1 to 85.122.255.25485.122.255.25532,766
24785.123.0.0/1785.123.0.1 to 85.123.127.25485.123.127.25532,766
24885.123.128.0/1785.123.128.1 to 85.123.255.25485.123.255.25532,766
24985.124.0.0/1785.124.0.1 to 85.124.127.25485.124.127.25532,766
25085.124.128.0/1785.124.128.1 to 85.124.255.25485.124.255.25532,766
25185.125.0.0/1785.125.0.1 to 85.125.127.25485.125.127.25532,766
25285.125.128.0/1785.125.128.1 to 85.125.255.25485.125.255.25532,766
25385.126.0.0/1785.126.0.1 to 85.126.127.25485.126.127.25532,766
25485.126.128.0/1785.126.128.1 to 85.126.255.25485.126.255.25532,766
25585.127.0.0/1785.127.0.1 to 85.127.127.25485.127.127.25532,766
25685.127.128.0/1785.127.128.1 to 85.127.255.25485.127.255.25532,766

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.