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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.

Network76.0.0.0/6
Usable hosts67,108,862
Subnet mask252.0.0.0
Addresses67,108,864
Network address
76.0.0.0
Broadcast address
79.255.255.255
First usable
76.0.0.1
Last usable
79.255.255.254
Usable hosts
67,108,862 (67,108,864 less the network and broadcast addresses)
Subnet mask
252.0.0.0
Wildcard mask
3.255.255.255 (Cisco ACLs, OSPF)
Prefix length
/6
Type
Public public
Old class
A (default /8)
As numbers
Hex 4C000000 · Integer 1275068416 to 1342177279
Reverse DNS zones
76.in-addr.arpa
77.in-addr.arpa
78.in-addr.arpa
79.in-addr.arpa
/6 is not on a 8-bit boundary, so it takes 4 /8 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address01001100.00000000.00000000.0000000076.0.0.0
Subnet mask11111100.00000000.00000000.00000000252.0.0.0
Network01001100.00000000.00000000.0000000076.0.0.0
Broadcast01001111.11111111.11111111.1111111179.255.255.255
Split into smaller subnets/18
/7 (2)/8 (4)/9 (8)/10 (16)/11 (32)/12 (64)/13 (128)/14 (256)/15 (512)/16 (1,024)/17 (2,048)/18 (4,096)

76.0.0.0/6 makes 4,096 subnets of /18; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
176.0.0.0/1876.0.0.1 to 76.0.63.25476.0.63.25516,382
276.0.64.0/1876.0.64.1 to 76.0.127.25476.0.127.25516,382
376.0.128.0/1876.0.128.1 to 76.0.191.25476.0.191.25516,382
476.0.192.0/1876.0.192.1 to 76.0.255.25476.0.255.25516,382
576.1.0.0/1876.1.0.1 to 76.1.63.25476.1.63.25516,382
676.1.64.0/1876.1.64.1 to 76.1.127.25476.1.127.25516,382
776.1.128.0/1876.1.128.1 to 76.1.191.25476.1.191.25516,382
876.1.192.0/1876.1.192.1 to 76.1.255.25476.1.255.25516,382
976.2.0.0/1876.2.0.1 to 76.2.63.25476.2.63.25516,382
1076.2.64.0/1876.2.64.1 to 76.2.127.25476.2.127.25516,382
1176.2.128.0/1876.2.128.1 to 76.2.191.25476.2.191.25516,382
1276.2.192.0/1876.2.192.1 to 76.2.255.25476.2.255.25516,382
1376.3.0.0/1876.3.0.1 to 76.3.63.25476.3.63.25516,382
1476.3.64.0/1876.3.64.1 to 76.3.127.25476.3.127.25516,382
1576.3.128.0/1876.3.128.1 to 76.3.191.25476.3.191.25516,382
1676.3.192.0/1876.3.192.1 to 76.3.255.25476.3.255.25516,382
1776.4.0.0/1876.4.0.1 to 76.4.63.25476.4.63.25516,382
1876.4.64.0/1876.4.64.1 to 76.4.127.25476.4.127.25516,382
1976.4.128.0/1876.4.128.1 to 76.4.191.25476.4.191.25516,382
2076.4.192.0/1876.4.192.1 to 76.4.255.25476.4.255.25516,382
2176.5.0.0/1876.5.0.1 to 76.5.63.25476.5.63.25516,382
2276.5.64.0/1876.5.64.1 to 76.5.127.25476.5.127.25516,382
2376.5.128.0/1876.5.128.1 to 76.5.191.25476.5.191.25516,382
2476.5.192.0/1876.5.192.1 to 76.5.255.25476.5.255.25516,382
2576.6.0.0/1876.6.0.1 to 76.6.63.25476.6.63.25516,382
2676.6.64.0/1876.6.64.1 to 76.6.127.25476.6.127.25516,382
2776.6.128.0/1876.6.128.1 to 76.6.191.25476.6.191.25516,382
2876.6.192.0/1876.6.192.1 to 76.6.255.25476.6.255.25516,382
2976.7.0.0/1876.7.0.1 to 76.7.63.25476.7.63.25516,382
3076.7.64.0/1876.7.64.1 to 76.7.127.25476.7.127.25516,382
3176.7.128.0/1876.7.128.1 to 76.7.191.25476.7.191.25516,382
3276.7.192.0/1876.7.192.1 to 76.7.255.25476.7.255.25516,382
3376.8.0.0/1876.8.0.1 to 76.8.63.25476.8.63.25516,382
3476.8.64.0/1876.8.64.1 to 76.8.127.25476.8.127.25516,382
3576.8.128.0/1876.8.128.1 to 76.8.191.25476.8.191.25516,382
3676.8.192.0/1876.8.192.1 to 76.8.255.25476.8.255.25516,382
3776.9.0.0/1876.9.0.1 to 76.9.63.25476.9.63.25516,382
3876.9.64.0/1876.9.64.1 to 76.9.127.25476.9.127.25516,382
3976.9.128.0/1876.9.128.1 to 76.9.191.25476.9.191.25516,382
4076.9.192.0/1876.9.192.1 to 76.9.255.25476.9.255.25516,382
4176.10.0.0/1876.10.0.1 to 76.10.63.25476.10.63.25516,382
4276.10.64.0/1876.10.64.1 to 76.10.127.25476.10.127.25516,382
4376.10.128.0/1876.10.128.1 to 76.10.191.25476.10.191.25516,382
4476.10.192.0/1876.10.192.1 to 76.10.255.25476.10.255.25516,382
4576.11.0.0/1876.11.0.1 to 76.11.63.25476.11.63.25516,382
4676.11.64.0/1876.11.64.1 to 76.11.127.25476.11.127.25516,382
4776.11.128.0/1876.11.128.1 to 76.11.191.25476.11.191.25516,382
4876.11.192.0/1876.11.192.1 to 76.11.255.25476.11.255.25516,382
4976.12.0.0/1876.12.0.1 to 76.12.63.25476.12.63.25516,382
5076.12.64.0/1876.12.64.1 to 76.12.127.25476.12.127.25516,382
5176.12.128.0/1876.12.128.1 to 76.12.191.25476.12.191.25516,382
5276.12.192.0/1876.12.192.1 to 76.12.255.25476.12.255.25516,382
5376.13.0.0/1876.13.0.1 to 76.13.63.25476.13.63.25516,382
5476.13.64.0/1876.13.64.1 to 76.13.127.25476.13.127.25516,382
5576.13.128.0/1876.13.128.1 to 76.13.191.25476.13.191.25516,382
5676.13.192.0/1876.13.192.1 to 76.13.255.25476.13.255.25516,382
5776.14.0.0/1876.14.0.1 to 76.14.63.25476.14.63.25516,382
5876.14.64.0/1876.14.64.1 to 76.14.127.25476.14.127.25516,382
5976.14.128.0/1876.14.128.1 to 76.14.191.25476.14.191.25516,382
6076.14.192.0/1876.14.192.1 to 76.14.255.25476.14.255.25516,382
6176.15.0.0/1876.15.0.1 to 76.15.63.25476.15.63.25516,382
6276.15.64.0/1876.15.64.1 to 76.15.127.25476.15.127.25516,382
6376.15.128.0/1876.15.128.1 to 76.15.191.25476.15.191.25516,382
6476.15.192.0/1876.15.192.1 to 76.15.255.25476.15.255.25516,382
6576.16.0.0/1876.16.0.1 to 76.16.63.25476.16.63.25516,382
6676.16.64.0/1876.16.64.1 to 76.16.127.25476.16.127.25516,382
6776.16.128.0/1876.16.128.1 to 76.16.191.25476.16.191.25516,382
6876.16.192.0/1876.16.192.1 to 76.16.255.25476.16.255.25516,382
6976.17.0.0/1876.17.0.1 to 76.17.63.25476.17.63.25516,382
7076.17.64.0/1876.17.64.1 to 76.17.127.25476.17.127.25516,382
7176.17.128.0/1876.17.128.1 to 76.17.191.25476.17.191.25516,382
7276.17.192.0/1876.17.192.1 to 76.17.255.25476.17.255.25516,382
7376.18.0.0/1876.18.0.1 to 76.18.63.25476.18.63.25516,382
7476.18.64.0/1876.18.64.1 to 76.18.127.25476.18.127.25516,382
7576.18.128.0/1876.18.128.1 to 76.18.191.25476.18.191.25516,382
7676.18.192.0/1876.18.192.1 to 76.18.255.25476.18.255.25516,382
7776.19.0.0/1876.19.0.1 to 76.19.63.25476.19.63.25516,382
7876.19.64.0/1876.19.64.1 to 76.19.127.25476.19.127.25516,382
7976.19.128.0/1876.19.128.1 to 76.19.191.25476.19.191.25516,382
8076.19.192.0/1876.19.192.1 to 76.19.255.25476.19.255.25516,382
8176.20.0.0/1876.20.0.1 to 76.20.63.25476.20.63.25516,382
8276.20.64.0/1876.20.64.1 to 76.20.127.25476.20.127.25516,382
8376.20.128.0/1876.20.128.1 to 76.20.191.25476.20.191.25516,382
8476.20.192.0/1876.20.192.1 to 76.20.255.25476.20.255.25516,382
8576.21.0.0/1876.21.0.1 to 76.21.63.25476.21.63.25516,382
8676.21.64.0/1876.21.64.1 to 76.21.127.25476.21.127.25516,382
8776.21.128.0/1876.21.128.1 to 76.21.191.25476.21.191.25516,382
8876.21.192.0/1876.21.192.1 to 76.21.255.25476.21.255.25516,382
8976.22.0.0/1876.22.0.1 to 76.22.63.25476.22.63.25516,382
9076.22.64.0/1876.22.64.1 to 76.22.127.25476.22.127.25516,382
9176.22.128.0/1876.22.128.1 to 76.22.191.25476.22.191.25516,382
9276.22.192.0/1876.22.192.1 to 76.22.255.25476.22.255.25516,382
9376.23.0.0/1876.23.0.1 to 76.23.63.25476.23.63.25516,382
9476.23.64.0/1876.23.64.1 to 76.23.127.25476.23.127.25516,382
9576.23.128.0/1876.23.128.1 to 76.23.191.25476.23.191.25516,382
9676.23.192.0/1876.23.192.1 to 76.23.255.25476.23.255.25516,382
9776.24.0.0/1876.24.0.1 to 76.24.63.25476.24.63.25516,382
9876.24.64.0/1876.24.64.1 to 76.24.127.25476.24.127.25516,382
9976.24.128.0/1876.24.128.1 to 76.24.191.25476.24.191.25516,382
10076.24.192.0/1876.24.192.1 to 76.24.255.25476.24.255.25516,382
10176.25.0.0/1876.25.0.1 to 76.25.63.25476.25.63.25516,382
10276.25.64.0/1876.25.64.1 to 76.25.127.25476.25.127.25516,382
10376.25.128.0/1876.25.128.1 to 76.25.191.25476.25.191.25516,382
10476.25.192.0/1876.25.192.1 to 76.25.255.25476.25.255.25516,382
10576.26.0.0/1876.26.0.1 to 76.26.63.25476.26.63.25516,382
10676.26.64.0/1876.26.64.1 to 76.26.127.25476.26.127.25516,382
10776.26.128.0/1876.26.128.1 to 76.26.191.25476.26.191.25516,382
10876.26.192.0/1876.26.192.1 to 76.26.255.25476.26.255.25516,382
10976.27.0.0/1876.27.0.1 to 76.27.63.25476.27.63.25516,382
11076.27.64.0/1876.27.64.1 to 76.27.127.25476.27.127.25516,382
11176.27.128.0/1876.27.128.1 to 76.27.191.25476.27.191.25516,382
11276.27.192.0/1876.27.192.1 to 76.27.255.25476.27.255.25516,382
11376.28.0.0/1876.28.0.1 to 76.28.63.25476.28.63.25516,382
11476.28.64.0/1876.28.64.1 to 76.28.127.25476.28.127.25516,382
11576.28.128.0/1876.28.128.1 to 76.28.191.25476.28.191.25516,382
11676.28.192.0/1876.28.192.1 to 76.28.255.25476.28.255.25516,382
11776.29.0.0/1876.29.0.1 to 76.29.63.25476.29.63.25516,382
11876.29.64.0/1876.29.64.1 to 76.29.127.25476.29.127.25516,382
11976.29.128.0/1876.29.128.1 to 76.29.191.25476.29.191.25516,382
12076.29.192.0/1876.29.192.1 to 76.29.255.25476.29.255.25516,382
12176.30.0.0/1876.30.0.1 to 76.30.63.25476.30.63.25516,382
12276.30.64.0/1876.30.64.1 to 76.30.127.25476.30.127.25516,382
12376.30.128.0/1876.30.128.1 to 76.30.191.25476.30.191.25516,382
12476.30.192.0/1876.30.192.1 to 76.30.255.25476.30.255.25516,382
12576.31.0.0/1876.31.0.1 to 76.31.63.25476.31.63.25516,382
12676.31.64.0/1876.31.64.1 to 76.31.127.25476.31.127.25516,382
12776.31.128.0/1876.31.128.1 to 76.31.191.25476.31.191.25516,382
12876.31.192.0/1876.31.192.1 to 76.31.255.25476.31.255.25516,382
12976.32.0.0/1876.32.0.1 to 76.32.63.25476.32.63.25516,382
13076.32.64.0/1876.32.64.1 to 76.32.127.25476.32.127.25516,382
13176.32.128.0/1876.32.128.1 to 76.32.191.25476.32.191.25516,382
13276.32.192.0/1876.32.192.1 to 76.32.255.25476.32.255.25516,382
13376.33.0.0/1876.33.0.1 to 76.33.63.25476.33.63.25516,382
13476.33.64.0/1876.33.64.1 to 76.33.127.25476.33.127.25516,382
13576.33.128.0/1876.33.128.1 to 76.33.191.25476.33.191.25516,382
13676.33.192.0/1876.33.192.1 to 76.33.255.25476.33.255.25516,382
13776.34.0.0/1876.34.0.1 to 76.34.63.25476.34.63.25516,382
13876.34.64.0/1876.34.64.1 to 76.34.127.25476.34.127.25516,382
13976.34.128.0/1876.34.128.1 to 76.34.191.25476.34.191.25516,382
14076.34.192.0/1876.34.192.1 to 76.34.255.25476.34.255.25516,382
14176.35.0.0/1876.35.0.1 to 76.35.63.25476.35.63.25516,382
14276.35.64.0/1876.35.64.1 to 76.35.127.25476.35.127.25516,382
14376.35.128.0/1876.35.128.1 to 76.35.191.25476.35.191.25516,382
14476.35.192.0/1876.35.192.1 to 76.35.255.25476.35.255.25516,382
14576.36.0.0/1876.36.0.1 to 76.36.63.25476.36.63.25516,382
14676.36.64.0/1876.36.64.1 to 76.36.127.25476.36.127.25516,382
14776.36.128.0/1876.36.128.1 to 76.36.191.25476.36.191.25516,382
14876.36.192.0/1876.36.192.1 to 76.36.255.25476.36.255.25516,382
14976.37.0.0/1876.37.0.1 to 76.37.63.25476.37.63.25516,382
15076.37.64.0/1876.37.64.1 to 76.37.127.25476.37.127.25516,382
15176.37.128.0/1876.37.128.1 to 76.37.191.25476.37.191.25516,382
15276.37.192.0/1876.37.192.1 to 76.37.255.25476.37.255.25516,382
15376.38.0.0/1876.38.0.1 to 76.38.63.25476.38.63.25516,382
15476.38.64.0/1876.38.64.1 to 76.38.127.25476.38.127.25516,382
15576.38.128.0/1876.38.128.1 to 76.38.191.25476.38.191.25516,382
15676.38.192.0/1876.38.192.1 to 76.38.255.25476.38.255.25516,382
15776.39.0.0/1876.39.0.1 to 76.39.63.25476.39.63.25516,382
15876.39.64.0/1876.39.64.1 to 76.39.127.25476.39.127.25516,382
15976.39.128.0/1876.39.128.1 to 76.39.191.25476.39.191.25516,382
16076.39.192.0/1876.39.192.1 to 76.39.255.25476.39.255.25516,382
16176.40.0.0/1876.40.0.1 to 76.40.63.25476.40.63.25516,382
16276.40.64.0/1876.40.64.1 to 76.40.127.25476.40.127.25516,382
16376.40.128.0/1876.40.128.1 to 76.40.191.25476.40.191.25516,382
16476.40.192.0/1876.40.192.1 to 76.40.255.25476.40.255.25516,382
16576.41.0.0/1876.41.0.1 to 76.41.63.25476.41.63.25516,382
16676.41.64.0/1876.41.64.1 to 76.41.127.25476.41.127.25516,382
16776.41.128.0/1876.41.128.1 to 76.41.191.25476.41.191.25516,382
16876.41.192.0/1876.41.192.1 to 76.41.255.25476.41.255.25516,382
16976.42.0.0/1876.42.0.1 to 76.42.63.25476.42.63.25516,382
17076.42.64.0/1876.42.64.1 to 76.42.127.25476.42.127.25516,382
17176.42.128.0/1876.42.128.1 to 76.42.191.25476.42.191.25516,382
17276.42.192.0/1876.42.192.1 to 76.42.255.25476.42.255.25516,382
17376.43.0.0/1876.43.0.1 to 76.43.63.25476.43.63.25516,382
17476.43.64.0/1876.43.64.1 to 76.43.127.25476.43.127.25516,382
17576.43.128.0/1876.43.128.1 to 76.43.191.25476.43.191.25516,382
17676.43.192.0/1876.43.192.1 to 76.43.255.25476.43.255.25516,382
17776.44.0.0/1876.44.0.1 to 76.44.63.25476.44.63.25516,382
17876.44.64.0/1876.44.64.1 to 76.44.127.25476.44.127.25516,382
17976.44.128.0/1876.44.128.1 to 76.44.191.25476.44.191.25516,382
18076.44.192.0/1876.44.192.1 to 76.44.255.25476.44.255.25516,382
18176.45.0.0/1876.45.0.1 to 76.45.63.25476.45.63.25516,382
18276.45.64.0/1876.45.64.1 to 76.45.127.25476.45.127.25516,382
18376.45.128.0/1876.45.128.1 to 76.45.191.25476.45.191.25516,382
18476.45.192.0/1876.45.192.1 to 76.45.255.25476.45.255.25516,382
18576.46.0.0/1876.46.0.1 to 76.46.63.25476.46.63.25516,382
18676.46.64.0/1876.46.64.1 to 76.46.127.25476.46.127.25516,382
18776.46.128.0/1876.46.128.1 to 76.46.191.25476.46.191.25516,382
18876.46.192.0/1876.46.192.1 to 76.46.255.25476.46.255.25516,382
18976.47.0.0/1876.47.0.1 to 76.47.63.25476.47.63.25516,382
19076.47.64.0/1876.47.64.1 to 76.47.127.25476.47.127.25516,382
19176.47.128.0/1876.47.128.1 to 76.47.191.25476.47.191.25516,382
19276.47.192.0/1876.47.192.1 to 76.47.255.25476.47.255.25516,382
19376.48.0.0/1876.48.0.1 to 76.48.63.25476.48.63.25516,382
19476.48.64.0/1876.48.64.1 to 76.48.127.25476.48.127.25516,382
19576.48.128.0/1876.48.128.1 to 76.48.191.25476.48.191.25516,382
19676.48.192.0/1876.48.192.1 to 76.48.255.25476.48.255.25516,382
19776.49.0.0/1876.49.0.1 to 76.49.63.25476.49.63.25516,382
19876.49.64.0/1876.49.64.1 to 76.49.127.25476.49.127.25516,382
19976.49.128.0/1876.49.128.1 to 76.49.191.25476.49.191.25516,382
20076.49.192.0/1876.49.192.1 to 76.49.255.25476.49.255.25516,382
20176.50.0.0/1876.50.0.1 to 76.50.63.25476.50.63.25516,382
20276.50.64.0/1876.50.64.1 to 76.50.127.25476.50.127.25516,382
20376.50.128.0/1876.50.128.1 to 76.50.191.25476.50.191.25516,382
20476.50.192.0/1876.50.192.1 to 76.50.255.25476.50.255.25516,382
20576.51.0.0/1876.51.0.1 to 76.51.63.25476.51.63.25516,382
20676.51.64.0/1876.51.64.1 to 76.51.127.25476.51.127.25516,382
20776.51.128.0/1876.51.128.1 to 76.51.191.25476.51.191.25516,382
20876.51.192.0/1876.51.192.1 to 76.51.255.25476.51.255.25516,382
20976.52.0.0/1876.52.0.1 to 76.52.63.25476.52.63.25516,382
21076.52.64.0/1876.52.64.1 to 76.52.127.25476.52.127.25516,382
21176.52.128.0/1876.52.128.1 to 76.52.191.25476.52.191.25516,382
21276.52.192.0/1876.52.192.1 to 76.52.255.25476.52.255.25516,382
21376.53.0.0/1876.53.0.1 to 76.53.63.25476.53.63.25516,382
21476.53.64.0/1876.53.64.1 to 76.53.127.25476.53.127.25516,382
21576.53.128.0/1876.53.128.1 to 76.53.191.25476.53.191.25516,382
21676.53.192.0/1876.53.192.1 to 76.53.255.25476.53.255.25516,382
21776.54.0.0/1876.54.0.1 to 76.54.63.25476.54.63.25516,382
21876.54.64.0/1876.54.64.1 to 76.54.127.25476.54.127.25516,382
21976.54.128.0/1876.54.128.1 to 76.54.191.25476.54.191.25516,382
22076.54.192.0/1876.54.192.1 to 76.54.255.25476.54.255.25516,382
22176.55.0.0/1876.55.0.1 to 76.55.63.25476.55.63.25516,382
22276.55.64.0/1876.55.64.1 to 76.55.127.25476.55.127.25516,382
22376.55.128.0/1876.55.128.1 to 76.55.191.25476.55.191.25516,382
22476.55.192.0/1876.55.192.1 to 76.55.255.25476.55.255.25516,382
22576.56.0.0/1876.56.0.1 to 76.56.63.25476.56.63.25516,382
22676.56.64.0/1876.56.64.1 to 76.56.127.25476.56.127.25516,382
22776.56.128.0/1876.56.128.1 to 76.56.191.25476.56.191.25516,382
22876.56.192.0/1876.56.192.1 to 76.56.255.25476.56.255.25516,382
22976.57.0.0/1876.57.0.1 to 76.57.63.25476.57.63.25516,382
23076.57.64.0/1876.57.64.1 to 76.57.127.25476.57.127.25516,382
23176.57.128.0/1876.57.128.1 to 76.57.191.25476.57.191.25516,382
23276.57.192.0/1876.57.192.1 to 76.57.255.25476.57.255.25516,382
23376.58.0.0/1876.58.0.1 to 76.58.63.25476.58.63.25516,382
23476.58.64.0/1876.58.64.1 to 76.58.127.25476.58.127.25516,382
23576.58.128.0/1876.58.128.1 to 76.58.191.25476.58.191.25516,382
23676.58.192.0/1876.58.192.1 to 76.58.255.25476.58.255.25516,382
23776.59.0.0/1876.59.0.1 to 76.59.63.25476.59.63.25516,382
23876.59.64.0/1876.59.64.1 to 76.59.127.25476.59.127.25516,382
23976.59.128.0/1876.59.128.1 to 76.59.191.25476.59.191.25516,382
24076.59.192.0/1876.59.192.1 to 76.59.255.25476.59.255.25516,382
24176.60.0.0/1876.60.0.1 to 76.60.63.25476.60.63.25516,382
24276.60.64.0/1876.60.64.1 to 76.60.127.25476.60.127.25516,382
24376.60.128.0/1876.60.128.1 to 76.60.191.25476.60.191.25516,382
24476.60.192.0/1876.60.192.1 to 76.60.255.25476.60.255.25516,382
24576.61.0.0/1876.61.0.1 to 76.61.63.25476.61.63.25516,382
24676.61.64.0/1876.61.64.1 to 76.61.127.25476.61.127.25516,382
24776.61.128.0/1876.61.128.1 to 76.61.191.25476.61.191.25516,382
24876.61.192.0/1876.61.192.1 to 76.61.255.25476.61.255.25516,382
24976.62.0.0/1876.62.0.1 to 76.62.63.25476.62.63.25516,382
25076.62.64.0/1876.62.64.1 to 76.62.127.25476.62.127.25516,382
25176.62.128.0/1876.62.128.1 to 76.62.191.25476.62.191.25516,382
25276.62.192.0/1876.62.192.1 to 76.62.255.25476.62.255.25516,382
25376.63.0.0/1876.63.0.1 to 76.63.63.25476.63.63.25516,382
25476.63.64.0/1876.63.64.1 to 76.63.127.25476.63.127.25516,382
25576.63.128.0/1876.63.128.1 to 76.63.191.25476.63.191.25516,382
25676.63.192.0/1876.63.192.1 to 76.63.255.25476.63.255.25516,382

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.