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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.

Network41.0.0.0/8
Usable hosts16,777,214
Subnet mask255.0.0.0
Addresses16,777,216
Network address
41.0.0.0
Broadcast address
41.255.255.255
First usable
41.0.0.1
Last usable
41.255.255.254
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 29000000 · Integer 687865856 to 704643071
Reverse DNS zone
41.in-addr.arpa
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address00101001..00000000.00000000.0000000041.0.0.0
Subnet mask11111111..00000000.00000000.00000000255.0.0.0
Network00101001..00000000.00000000.0000000041.0.0.0
Broadcast00101001..11111111.11111111.1111111141.255.255.255
Split into smaller subnets/18
/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)

41.0.0.0/8 makes 1,024 subnets of /18; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
141.0.0.0/1841.0.0.1 to 41.0.63.25441.0.63.25516,382
241.0.64.0/1841.0.64.1 to 41.0.127.25441.0.127.25516,382
341.0.128.0/1841.0.128.1 to 41.0.191.25441.0.191.25516,382
441.0.192.0/1841.0.192.1 to 41.0.255.25441.0.255.25516,382
541.1.0.0/1841.1.0.1 to 41.1.63.25441.1.63.25516,382
641.1.64.0/1841.1.64.1 to 41.1.127.25441.1.127.25516,382
741.1.128.0/1841.1.128.1 to 41.1.191.25441.1.191.25516,382
841.1.192.0/1841.1.192.1 to 41.1.255.25441.1.255.25516,382
941.2.0.0/1841.2.0.1 to 41.2.63.25441.2.63.25516,382
1041.2.64.0/1841.2.64.1 to 41.2.127.25441.2.127.25516,382
1141.2.128.0/1841.2.128.1 to 41.2.191.25441.2.191.25516,382
1241.2.192.0/1841.2.192.1 to 41.2.255.25441.2.255.25516,382
1341.3.0.0/1841.3.0.1 to 41.3.63.25441.3.63.25516,382
1441.3.64.0/1841.3.64.1 to 41.3.127.25441.3.127.25516,382
1541.3.128.0/1841.3.128.1 to 41.3.191.25441.3.191.25516,382
1641.3.192.0/1841.3.192.1 to 41.3.255.25441.3.255.25516,382
1741.4.0.0/1841.4.0.1 to 41.4.63.25441.4.63.25516,382
1841.4.64.0/1841.4.64.1 to 41.4.127.25441.4.127.25516,382
1941.4.128.0/1841.4.128.1 to 41.4.191.25441.4.191.25516,382
2041.4.192.0/1841.4.192.1 to 41.4.255.25441.4.255.25516,382
2141.5.0.0/1841.5.0.1 to 41.5.63.25441.5.63.25516,382
2241.5.64.0/1841.5.64.1 to 41.5.127.25441.5.127.25516,382
2341.5.128.0/1841.5.128.1 to 41.5.191.25441.5.191.25516,382
2441.5.192.0/1841.5.192.1 to 41.5.255.25441.5.255.25516,382
2541.6.0.0/1841.6.0.1 to 41.6.63.25441.6.63.25516,382
2641.6.64.0/1841.6.64.1 to 41.6.127.25441.6.127.25516,382
2741.6.128.0/1841.6.128.1 to 41.6.191.25441.6.191.25516,382
2841.6.192.0/1841.6.192.1 to 41.6.255.25441.6.255.25516,382
2941.7.0.0/1841.7.0.1 to 41.7.63.25441.7.63.25516,382
3041.7.64.0/1841.7.64.1 to 41.7.127.25441.7.127.25516,382
3141.7.128.0/1841.7.128.1 to 41.7.191.25441.7.191.25516,382
3241.7.192.0/1841.7.192.1 to 41.7.255.25441.7.255.25516,382
3341.8.0.0/1841.8.0.1 to 41.8.63.25441.8.63.25516,382
3441.8.64.0/1841.8.64.1 to 41.8.127.25441.8.127.25516,382
3541.8.128.0/1841.8.128.1 to 41.8.191.25441.8.191.25516,382
3641.8.192.0/1841.8.192.1 to 41.8.255.25441.8.255.25516,382
3741.9.0.0/1841.9.0.1 to 41.9.63.25441.9.63.25516,382
3841.9.64.0/1841.9.64.1 to 41.9.127.25441.9.127.25516,382
3941.9.128.0/1841.9.128.1 to 41.9.191.25441.9.191.25516,382
4041.9.192.0/1841.9.192.1 to 41.9.255.25441.9.255.25516,382
4141.10.0.0/1841.10.0.1 to 41.10.63.25441.10.63.25516,382
4241.10.64.0/1841.10.64.1 to 41.10.127.25441.10.127.25516,382
4341.10.128.0/1841.10.128.1 to 41.10.191.25441.10.191.25516,382
4441.10.192.0/1841.10.192.1 to 41.10.255.25441.10.255.25516,382
4541.11.0.0/1841.11.0.1 to 41.11.63.25441.11.63.25516,382
4641.11.64.0/1841.11.64.1 to 41.11.127.25441.11.127.25516,382
4741.11.128.0/1841.11.128.1 to 41.11.191.25441.11.191.25516,382
4841.11.192.0/1841.11.192.1 to 41.11.255.25441.11.255.25516,382
4941.12.0.0/1841.12.0.1 to 41.12.63.25441.12.63.25516,382
5041.12.64.0/1841.12.64.1 to 41.12.127.25441.12.127.25516,382
5141.12.128.0/1841.12.128.1 to 41.12.191.25441.12.191.25516,382
5241.12.192.0/1841.12.192.1 to 41.12.255.25441.12.255.25516,382
5341.13.0.0/1841.13.0.1 to 41.13.63.25441.13.63.25516,382
5441.13.64.0/1841.13.64.1 to 41.13.127.25441.13.127.25516,382
5541.13.128.0/1841.13.128.1 to 41.13.191.25441.13.191.25516,382
5641.13.192.0/1841.13.192.1 to 41.13.255.25441.13.255.25516,382
5741.14.0.0/1841.14.0.1 to 41.14.63.25441.14.63.25516,382
5841.14.64.0/1841.14.64.1 to 41.14.127.25441.14.127.25516,382
5941.14.128.0/1841.14.128.1 to 41.14.191.25441.14.191.25516,382
6041.14.192.0/1841.14.192.1 to 41.14.255.25441.14.255.25516,382
6141.15.0.0/1841.15.0.1 to 41.15.63.25441.15.63.25516,382
6241.15.64.0/1841.15.64.1 to 41.15.127.25441.15.127.25516,382
6341.15.128.0/1841.15.128.1 to 41.15.191.25441.15.191.25516,382
6441.15.192.0/1841.15.192.1 to 41.15.255.25441.15.255.25516,382
6541.16.0.0/1841.16.0.1 to 41.16.63.25441.16.63.25516,382
6641.16.64.0/1841.16.64.1 to 41.16.127.25441.16.127.25516,382
6741.16.128.0/1841.16.128.1 to 41.16.191.25441.16.191.25516,382
6841.16.192.0/1841.16.192.1 to 41.16.255.25441.16.255.25516,382
6941.17.0.0/1841.17.0.1 to 41.17.63.25441.17.63.25516,382
7041.17.64.0/1841.17.64.1 to 41.17.127.25441.17.127.25516,382
7141.17.128.0/1841.17.128.1 to 41.17.191.25441.17.191.25516,382
7241.17.192.0/1841.17.192.1 to 41.17.255.25441.17.255.25516,382
7341.18.0.0/1841.18.0.1 to 41.18.63.25441.18.63.25516,382
7441.18.64.0/1841.18.64.1 to 41.18.127.25441.18.127.25516,382
7541.18.128.0/1841.18.128.1 to 41.18.191.25441.18.191.25516,382
7641.18.192.0/1841.18.192.1 to 41.18.255.25441.18.255.25516,382
7741.19.0.0/1841.19.0.1 to 41.19.63.25441.19.63.25516,382
7841.19.64.0/1841.19.64.1 to 41.19.127.25441.19.127.25516,382
7941.19.128.0/1841.19.128.1 to 41.19.191.25441.19.191.25516,382
8041.19.192.0/1841.19.192.1 to 41.19.255.25441.19.255.25516,382
8141.20.0.0/1841.20.0.1 to 41.20.63.25441.20.63.25516,382
8241.20.64.0/1841.20.64.1 to 41.20.127.25441.20.127.25516,382
8341.20.128.0/1841.20.128.1 to 41.20.191.25441.20.191.25516,382
8441.20.192.0/1841.20.192.1 to 41.20.255.25441.20.255.25516,382
8541.21.0.0/1841.21.0.1 to 41.21.63.25441.21.63.25516,382
8641.21.64.0/1841.21.64.1 to 41.21.127.25441.21.127.25516,382
8741.21.128.0/1841.21.128.1 to 41.21.191.25441.21.191.25516,382
8841.21.192.0/1841.21.192.1 to 41.21.255.25441.21.255.25516,382
8941.22.0.0/1841.22.0.1 to 41.22.63.25441.22.63.25516,382
9041.22.64.0/1841.22.64.1 to 41.22.127.25441.22.127.25516,382
9141.22.128.0/1841.22.128.1 to 41.22.191.25441.22.191.25516,382
9241.22.192.0/1841.22.192.1 to 41.22.255.25441.22.255.25516,382
9341.23.0.0/1841.23.0.1 to 41.23.63.25441.23.63.25516,382
9441.23.64.0/1841.23.64.1 to 41.23.127.25441.23.127.25516,382
9541.23.128.0/1841.23.128.1 to 41.23.191.25441.23.191.25516,382
9641.23.192.0/1841.23.192.1 to 41.23.255.25441.23.255.25516,382
9741.24.0.0/1841.24.0.1 to 41.24.63.25441.24.63.25516,382
9841.24.64.0/1841.24.64.1 to 41.24.127.25441.24.127.25516,382
9941.24.128.0/1841.24.128.1 to 41.24.191.25441.24.191.25516,382
10041.24.192.0/1841.24.192.1 to 41.24.255.25441.24.255.25516,382
10141.25.0.0/1841.25.0.1 to 41.25.63.25441.25.63.25516,382
10241.25.64.0/1841.25.64.1 to 41.25.127.25441.25.127.25516,382
10341.25.128.0/1841.25.128.1 to 41.25.191.25441.25.191.25516,382
10441.25.192.0/1841.25.192.1 to 41.25.255.25441.25.255.25516,382
10541.26.0.0/1841.26.0.1 to 41.26.63.25441.26.63.25516,382
10641.26.64.0/1841.26.64.1 to 41.26.127.25441.26.127.25516,382
10741.26.128.0/1841.26.128.1 to 41.26.191.25441.26.191.25516,382
10841.26.192.0/1841.26.192.1 to 41.26.255.25441.26.255.25516,382
10941.27.0.0/1841.27.0.1 to 41.27.63.25441.27.63.25516,382
11041.27.64.0/1841.27.64.1 to 41.27.127.25441.27.127.25516,382
11141.27.128.0/1841.27.128.1 to 41.27.191.25441.27.191.25516,382
11241.27.192.0/1841.27.192.1 to 41.27.255.25441.27.255.25516,382
11341.28.0.0/1841.28.0.1 to 41.28.63.25441.28.63.25516,382
11441.28.64.0/1841.28.64.1 to 41.28.127.25441.28.127.25516,382
11541.28.128.0/1841.28.128.1 to 41.28.191.25441.28.191.25516,382
11641.28.192.0/1841.28.192.1 to 41.28.255.25441.28.255.25516,382
11741.29.0.0/1841.29.0.1 to 41.29.63.25441.29.63.25516,382
11841.29.64.0/1841.29.64.1 to 41.29.127.25441.29.127.25516,382
11941.29.128.0/1841.29.128.1 to 41.29.191.25441.29.191.25516,382
12041.29.192.0/1841.29.192.1 to 41.29.255.25441.29.255.25516,382
12141.30.0.0/1841.30.0.1 to 41.30.63.25441.30.63.25516,382
12241.30.64.0/1841.30.64.1 to 41.30.127.25441.30.127.25516,382
12341.30.128.0/1841.30.128.1 to 41.30.191.25441.30.191.25516,382
12441.30.192.0/1841.30.192.1 to 41.30.255.25441.30.255.25516,382
12541.31.0.0/1841.31.0.1 to 41.31.63.25441.31.63.25516,382
12641.31.64.0/1841.31.64.1 to 41.31.127.25441.31.127.25516,382
12741.31.128.0/1841.31.128.1 to 41.31.191.25441.31.191.25516,382
12841.31.192.0/1841.31.192.1 to 41.31.255.25441.31.255.25516,382
12941.32.0.0/1841.32.0.1 to 41.32.63.25441.32.63.25516,382
13041.32.64.0/1841.32.64.1 to 41.32.127.25441.32.127.25516,382
13141.32.128.0/1841.32.128.1 to 41.32.191.25441.32.191.25516,382
13241.32.192.0/1841.32.192.1 to 41.32.255.25441.32.255.25516,382
13341.33.0.0/1841.33.0.1 to 41.33.63.25441.33.63.25516,382
13441.33.64.0/1841.33.64.1 to 41.33.127.25441.33.127.25516,382
13541.33.128.0/1841.33.128.1 to 41.33.191.25441.33.191.25516,382
13641.33.192.0/1841.33.192.1 to 41.33.255.25441.33.255.25516,382
13741.34.0.0/1841.34.0.1 to 41.34.63.25441.34.63.25516,382
13841.34.64.0/1841.34.64.1 to 41.34.127.25441.34.127.25516,382
13941.34.128.0/1841.34.128.1 to 41.34.191.25441.34.191.25516,382
14041.34.192.0/1841.34.192.1 to 41.34.255.25441.34.255.25516,382
14141.35.0.0/1841.35.0.1 to 41.35.63.25441.35.63.25516,382
14241.35.64.0/1841.35.64.1 to 41.35.127.25441.35.127.25516,382
14341.35.128.0/1841.35.128.1 to 41.35.191.25441.35.191.25516,382
14441.35.192.0/1841.35.192.1 to 41.35.255.25441.35.255.25516,382
14541.36.0.0/1841.36.0.1 to 41.36.63.25441.36.63.25516,382
14641.36.64.0/1841.36.64.1 to 41.36.127.25441.36.127.25516,382
14741.36.128.0/1841.36.128.1 to 41.36.191.25441.36.191.25516,382
14841.36.192.0/1841.36.192.1 to 41.36.255.25441.36.255.25516,382
14941.37.0.0/1841.37.0.1 to 41.37.63.25441.37.63.25516,382
15041.37.64.0/1841.37.64.1 to 41.37.127.25441.37.127.25516,382
15141.37.128.0/1841.37.128.1 to 41.37.191.25441.37.191.25516,382
15241.37.192.0/1841.37.192.1 to 41.37.255.25441.37.255.25516,382
15341.38.0.0/1841.38.0.1 to 41.38.63.25441.38.63.25516,382
15441.38.64.0/1841.38.64.1 to 41.38.127.25441.38.127.25516,382
15541.38.128.0/1841.38.128.1 to 41.38.191.25441.38.191.25516,382
15641.38.192.0/1841.38.192.1 to 41.38.255.25441.38.255.25516,382
15741.39.0.0/1841.39.0.1 to 41.39.63.25441.39.63.25516,382
15841.39.64.0/1841.39.64.1 to 41.39.127.25441.39.127.25516,382
15941.39.128.0/1841.39.128.1 to 41.39.191.25441.39.191.25516,382
16041.39.192.0/1841.39.192.1 to 41.39.255.25441.39.255.25516,382
16141.40.0.0/1841.40.0.1 to 41.40.63.25441.40.63.25516,382
16241.40.64.0/1841.40.64.1 to 41.40.127.25441.40.127.25516,382
16341.40.128.0/1841.40.128.1 to 41.40.191.25441.40.191.25516,382
16441.40.192.0/1841.40.192.1 to 41.40.255.25441.40.255.25516,382
16541.41.0.0/1841.41.0.1 to 41.41.63.25441.41.63.25516,382
16641.41.64.0/1841.41.64.1 to 41.41.127.25441.41.127.25516,382
16741.41.128.0/1841.41.128.1 to 41.41.191.25441.41.191.25516,382
16841.41.192.0/1841.41.192.1 to 41.41.255.25441.41.255.25516,382
16941.42.0.0/1841.42.0.1 to 41.42.63.25441.42.63.25516,382
17041.42.64.0/1841.42.64.1 to 41.42.127.25441.42.127.25516,382
17141.42.128.0/1841.42.128.1 to 41.42.191.25441.42.191.25516,382
17241.42.192.0/1841.42.192.1 to 41.42.255.25441.42.255.25516,382
17341.43.0.0/1841.43.0.1 to 41.43.63.25441.43.63.25516,382
17441.43.64.0/1841.43.64.1 to 41.43.127.25441.43.127.25516,382
17541.43.128.0/1841.43.128.1 to 41.43.191.25441.43.191.25516,382
17641.43.192.0/1841.43.192.1 to 41.43.255.25441.43.255.25516,382
17741.44.0.0/1841.44.0.1 to 41.44.63.25441.44.63.25516,382
17841.44.64.0/1841.44.64.1 to 41.44.127.25441.44.127.25516,382
17941.44.128.0/1841.44.128.1 to 41.44.191.25441.44.191.25516,382
18041.44.192.0/1841.44.192.1 to 41.44.255.25441.44.255.25516,382
18141.45.0.0/1841.45.0.1 to 41.45.63.25441.45.63.25516,382
18241.45.64.0/1841.45.64.1 to 41.45.127.25441.45.127.25516,382
18341.45.128.0/1841.45.128.1 to 41.45.191.25441.45.191.25516,382
18441.45.192.0/1841.45.192.1 to 41.45.255.25441.45.255.25516,382
18541.46.0.0/1841.46.0.1 to 41.46.63.25441.46.63.25516,382
18641.46.64.0/1841.46.64.1 to 41.46.127.25441.46.127.25516,382
18741.46.128.0/1841.46.128.1 to 41.46.191.25441.46.191.25516,382
18841.46.192.0/1841.46.192.1 to 41.46.255.25441.46.255.25516,382
18941.47.0.0/1841.47.0.1 to 41.47.63.25441.47.63.25516,382
19041.47.64.0/1841.47.64.1 to 41.47.127.25441.47.127.25516,382
19141.47.128.0/1841.47.128.1 to 41.47.191.25441.47.191.25516,382
19241.47.192.0/1841.47.192.1 to 41.47.255.25441.47.255.25516,382
19341.48.0.0/1841.48.0.1 to 41.48.63.25441.48.63.25516,382
19441.48.64.0/1841.48.64.1 to 41.48.127.25441.48.127.25516,382
19541.48.128.0/1841.48.128.1 to 41.48.191.25441.48.191.25516,382
19641.48.192.0/1841.48.192.1 to 41.48.255.25441.48.255.25516,382
19741.49.0.0/1841.49.0.1 to 41.49.63.25441.49.63.25516,382
19841.49.64.0/1841.49.64.1 to 41.49.127.25441.49.127.25516,382
19941.49.128.0/1841.49.128.1 to 41.49.191.25441.49.191.25516,382
20041.49.192.0/1841.49.192.1 to 41.49.255.25441.49.255.25516,382
20141.50.0.0/1841.50.0.1 to 41.50.63.25441.50.63.25516,382
20241.50.64.0/1841.50.64.1 to 41.50.127.25441.50.127.25516,382
20341.50.128.0/1841.50.128.1 to 41.50.191.25441.50.191.25516,382
20441.50.192.0/1841.50.192.1 to 41.50.255.25441.50.255.25516,382
20541.51.0.0/1841.51.0.1 to 41.51.63.25441.51.63.25516,382
20641.51.64.0/1841.51.64.1 to 41.51.127.25441.51.127.25516,382
20741.51.128.0/1841.51.128.1 to 41.51.191.25441.51.191.25516,382
20841.51.192.0/1841.51.192.1 to 41.51.255.25441.51.255.25516,382
20941.52.0.0/1841.52.0.1 to 41.52.63.25441.52.63.25516,382
21041.52.64.0/1841.52.64.1 to 41.52.127.25441.52.127.25516,382
21141.52.128.0/1841.52.128.1 to 41.52.191.25441.52.191.25516,382
21241.52.192.0/1841.52.192.1 to 41.52.255.25441.52.255.25516,382
21341.53.0.0/1841.53.0.1 to 41.53.63.25441.53.63.25516,382
21441.53.64.0/1841.53.64.1 to 41.53.127.25441.53.127.25516,382
21541.53.128.0/1841.53.128.1 to 41.53.191.25441.53.191.25516,382
21641.53.192.0/1841.53.192.1 to 41.53.255.25441.53.255.25516,382
21741.54.0.0/1841.54.0.1 to 41.54.63.25441.54.63.25516,382
21841.54.64.0/1841.54.64.1 to 41.54.127.25441.54.127.25516,382
21941.54.128.0/1841.54.128.1 to 41.54.191.25441.54.191.25516,382
22041.54.192.0/1841.54.192.1 to 41.54.255.25441.54.255.25516,382
22141.55.0.0/1841.55.0.1 to 41.55.63.25441.55.63.25516,382
22241.55.64.0/1841.55.64.1 to 41.55.127.25441.55.127.25516,382
22341.55.128.0/1841.55.128.1 to 41.55.191.25441.55.191.25516,382
22441.55.192.0/1841.55.192.1 to 41.55.255.25441.55.255.25516,382
22541.56.0.0/1841.56.0.1 to 41.56.63.25441.56.63.25516,382
22641.56.64.0/1841.56.64.1 to 41.56.127.25441.56.127.25516,382
22741.56.128.0/1841.56.128.1 to 41.56.191.25441.56.191.25516,382
22841.56.192.0/1841.56.192.1 to 41.56.255.25441.56.255.25516,382
22941.57.0.0/1841.57.0.1 to 41.57.63.25441.57.63.25516,382
23041.57.64.0/1841.57.64.1 to 41.57.127.25441.57.127.25516,382
23141.57.128.0/1841.57.128.1 to 41.57.191.25441.57.191.25516,382
23241.57.192.0/1841.57.192.1 to 41.57.255.25441.57.255.25516,382
23341.58.0.0/1841.58.0.1 to 41.58.63.25441.58.63.25516,382
23441.58.64.0/1841.58.64.1 to 41.58.127.25441.58.127.25516,382
23541.58.128.0/1841.58.128.1 to 41.58.191.25441.58.191.25516,382
23641.58.192.0/1841.58.192.1 to 41.58.255.25441.58.255.25516,382
23741.59.0.0/1841.59.0.1 to 41.59.63.25441.59.63.25516,382
23841.59.64.0/1841.59.64.1 to 41.59.127.25441.59.127.25516,382
23941.59.128.0/1841.59.128.1 to 41.59.191.25441.59.191.25516,382
24041.59.192.0/1841.59.192.1 to 41.59.255.25441.59.255.25516,382
24141.60.0.0/1841.60.0.1 to 41.60.63.25441.60.63.25516,382
24241.60.64.0/1841.60.64.1 to 41.60.127.25441.60.127.25516,382
24341.60.128.0/1841.60.128.1 to 41.60.191.25441.60.191.25516,382
24441.60.192.0/1841.60.192.1 to 41.60.255.25441.60.255.25516,382
24541.61.0.0/1841.61.0.1 to 41.61.63.25441.61.63.25516,382
24641.61.64.0/1841.61.64.1 to 41.61.127.25441.61.127.25516,382
24741.61.128.0/1841.61.128.1 to 41.61.191.25441.61.191.25516,382
24841.61.192.0/1841.61.192.1 to 41.61.255.25441.61.255.25516,382
24941.62.0.0/1841.62.0.1 to 41.62.63.25441.62.63.25516,382
25041.62.64.0/1841.62.64.1 to 41.62.127.25441.62.127.25516,382
25141.62.128.0/1841.62.128.1 to 41.62.191.25441.62.191.25516,382
25241.62.192.0/1841.62.192.1 to 41.62.255.25441.62.255.25516,382
25341.63.0.0/1841.63.0.1 to 41.63.63.25441.63.63.25516,382
25441.63.64.0/1841.63.64.1 to 41.63.127.25441.63.127.25516,382
25541.63.128.0/1841.63.128.1 to 41.63.191.25441.63.191.25516,382
25641.63.192.0/1841.63.192.1 to 41.63.255.25441.63.255.25516,382

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.