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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.

Network57.0.0.0/8
Usable hosts16,777,214
Subnet mask255.0.0.0
Addresses16,777,216
Network address
57.0.0.0
Broadcast address
57.255.255.255
First usable
57.0.0.1
Last usable
57.255.255.254
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 39000000 · Integer 956301312 to 973078527
Reverse DNS zone
57.in-addr.arpa
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address00111001..00000000.00000000.0000000057.0.0.0
Subnet mask11111111..00000000.00000000.00000000255.0.0.0
Network00111001..00000000.00000000.0000000057.0.0.0
Broadcast00111001..11111111.11111111.1111111157.255.255.255
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)

57.0.0.0/8 makes 1,024 subnets of /18; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
157.0.0.0/1857.0.0.1 to 57.0.63.25457.0.63.25516,382
257.0.64.0/1857.0.64.1 to 57.0.127.25457.0.127.25516,382
357.0.128.0/1857.0.128.1 to 57.0.191.25457.0.191.25516,382
457.0.192.0/1857.0.192.1 to 57.0.255.25457.0.255.25516,382
557.1.0.0/1857.1.0.1 to 57.1.63.25457.1.63.25516,382
657.1.64.0/1857.1.64.1 to 57.1.127.25457.1.127.25516,382
757.1.128.0/1857.1.128.1 to 57.1.191.25457.1.191.25516,382
857.1.192.0/1857.1.192.1 to 57.1.255.25457.1.255.25516,382
957.2.0.0/1857.2.0.1 to 57.2.63.25457.2.63.25516,382
1057.2.64.0/1857.2.64.1 to 57.2.127.25457.2.127.25516,382
1157.2.128.0/1857.2.128.1 to 57.2.191.25457.2.191.25516,382
1257.2.192.0/1857.2.192.1 to 57.2.255.25457.2.255.25516,382
1357.3.0.0/1857.3.0.1 to 57.3.63.25457.3.63.25516,382
1457.3.64.0/1857.3.64.1 to 57.3.127.25457.3.127.25516,382
1557.3.128.0/1857.3.128.1 to 57.3.191.25457.3.191.25516,382
1657.3.192.0/1857.3.192.1 to 57.3.255.25457.3.255.25516,382
1757.4.0.0/1857.4.0.1 to 57.4.63.25457.4.63.25516,382
1857.4.64.0/1857.4.64.1 to 57.4.127.25457.4.127.25516,382
1957.4.128.0/1857.4.128.1 to 57.4.191.25457.4.191.25516,382
2057.4.192.0/1857.4.192.1 to 57.4.255.25457.4.255.25516,382
2157.5.0.0/1857.5.0.1 to 57.5.63.25457.5.63.25516,382
2257.5.64.0/1857.5.64.1 to 57.5.127.25457.5.127.25516,382
2357.5.128.0/1857.5.128.1 to 57.5.191.25457.5.191.25516,382
2457.5.192.0/1857.5.192.1 to 57.5.255.25457.5.255.25516,382
2557.6.0.0/1857.6.0.1 to 57.6.63.25457.6.63.25516,382
2657.6.64.0/1857.6.64.1 to 57.6.127.25457.6.127.25516,382
2757.6.128.0/1857.6.128.1 to 57.6.191.25457.6.191.25516,382
2857.6.192.0/1857.6.192.1 to 57.6.255.25457.6.255.25516,382
2957.7.0.0/1857.7.0.1 to 57.7.63.25457.7.63.25516,382
3057.7.64.0/1857.7.64.1 to 57.7.127.25457.7.127.25516,382
3157.7.128.0/1857.7.128.1 to 57.7.191.25457.7.191.25516,382
3257.7.192.0/1857.7.192.1 to 57.7.255.25457.7.255.25516,382
3357.8.0.0/1857.8.0.1 to 57.8.63.25457.8.63.25516,382
3457.8.64.0/1857.8.64.1 to 57.8.127.25457.8.127.25516,382
3557.8.128.0/1857.8.128.1 to 57.8.191.25457.8.191.25516,382
3657.8.192.0/1857.8.192.1 to 57.8.255.25457.8.255.25516,382
3757.9.0.0/1857.9.0.1 to 57.9.63.25457.9.63.25516,382
3857.9.64.0/1857.9.64.1 to 57.9.127.25457.9.127.25516,382
3957.9.128.0/1857.9.128.1 to 57.9.191.25457.9.191.25516,382
4057.9.192.0/1857.9.192.1 to 57.9.255.25457.9.255.25516,382
4157.10.0.0/1857.10.0.1 to 57.10.63.25457.10.63.25516,382
4257.10.64.0/1857.10.64.1 to 57.10.127.25457.10.127.25516,382
4357.10.128.0/1857.10.128.1 to 57.10.191.25457.10.191.25516,382
4457.10.192.0/1857.10.192.1 to 57.10.255.25457.10.255.25516,382
4557.11.0.0/1857.11.0.1 to 57.11.63.25457.11.63.25516,382
4657.11.64.0/1857.11.64.1 to 57.11.127.25457.11.127.25516,382
4757.11.128.0/1857.11.128.1 to 57.11.191.25457.11.191.25516,382
4857.11.192.0/1857.11.192.1 to 57.11.255.25457.11.255.25516,382
4957.12.0.0/1857.12.0.1 to 57.12.63.25457.12.63.25516,382
5057.12.64.0/1857.12.64.1 to 57.12.127.25457.12.127.25516,382
5157.12.128.0/1857.12.128.1 to 57.12.191.25457.12.191.25516,382
5257.12.192.0/1857.12.192.1 to 57.12.255.25457.12.255.25516,382
5357.13.0.0/1857.13.0.1 to 57.13.63.25457.13.63.25516,382
5457.13.64.0/1857.13.64.1 to 57.13.127.25457.13.127.25516,382
5557.13.128.0/1857.13.128.1 to 57.13.191.25457.13.191.25516,382
5657.13.192.0/1857.13.192.1 to 57.13.255.25457.13.255.25516,382
5757.14.0.0/1857.14.0.1 to 57.14.63.25457.14.63.25516,382
5857.14.64.0/1857.14.64.1 to 57.14.127.25457.14.127.25516,382
5957.14.128.0/1857.14.128.1 to 57.14.191.25457.14.191.25516,382
6057.14.192.0/1857.14.192.1 to 57.14.255.25457.14.255.25516,382
6157.15.0.0/1857.15.0.1 to 57.15.63.25457.15.63.25516,382
6257.15.64.0/1857.15.64.1 to 57.15.127.25457.15.127.25516,382
6357.15.128.0/1857.15.128.1 to 57.15.191.25457.15.191.25516,382
6457.15.192.0/1857.15.192.1 to 57.15.255.25457.15.255.25516,382
6557.16.0.0/1857.16.0.1 to 57.16.63.25457.16.63.25516,382
6657.16.64.0/1857.16.64.1 to 57.16.127.25457.16.127.25516,382
6757.16.128.0/1857.16.128.1 to 57.16.191.25457.16.191.25516,382
6857.16.192.0/1857.16.192.1 to 57.16.255.25457.16.255.25516,382
6957.17.0.0/1857.17.0.1 to 57.17.63.25457.17.63.25516,382
7057.17.64.0/1857.17.64.1 to 57.17.127.25457.17.127.25516,382
7157.17.128.0/1857.17.128.1 to 57.17.191.25457.17.191.25516,382
7257.17.192.0/1857.17.192.1 to 57.17.255.25457.17.255.25516,382
7357.18.0.0/1857.18.0.1 to 57.18.63.25457.18.63.25516,382
7457.18.64.0/1857.18.64.1 to 57.18.127.25457.18.127.25516,382
7557.18.128.0/1857.18.128.1 to 57.18.191.25457.18.191.25516,382
7657.18.192.0/1857.18.192.1 to 57.18.255.25457.18.255.25516,382
7757.19.0.0/1857.19.0.1 to 57.19.63.25457.19.63.25516,382
7857.19.64.0/1857.19.64.1 to 57.19.127.25457.19.127.25516,382
7957.19.128.0/1857.19.128.1 to 57.19.191.25457.19.191.25516,382
8057.19.192.0/1857.19.192.1 to 57.19.255.25457.19.255.25516,382
8157.20.0.0/1857.20.0.1 to 57.20.63.25457.20.63.25516,382
8257.20.64.0/1857.20.64.1 to 57.20.127.25457.20.127.25516,382
8357.20.128.0/1857.20.128.1 to 57.20.191.25457.20.191.25516,382
8457.20.192.0/1857.20.192.1 to 57.20.255.25457.20.255.25516,382
8557.21.0.0/1857.21.0.1 to 57.21.63.25457.21.63.25516,382
8657.21.64.0/1857.21.64.1 to 57.21.127.25457.21.127.25516,382
8757.21.128.0/1857.21.128.1 to 57.21.191.25457.21.191.25516,382
8857.21.192.0/1857.21.192.1 to 57.21.255.25457.21.255.25516,382
8957.22.0.0/1857.22.0.1 to 57.22.63.25457.22.63.25516,382
9057.22.64.0/1857.22.64.1 to 57.22.127.25457.22.127.25516,382
9157.22.128.0/1857.22.128.1 to 57.22.191.25457.22.191.25516,382
9257.22.192.0/1857.22.192.1 to 57.22.255.25457.22.255.25516,382
9357.23.0.0/1857.23.0.1 to 57.23.63.25457.23.63.25516,382
9457.23.64.0/1857.23.64.1 to 57.23.127.25457.23.127.25516,382
9557.23.128.0/1857.23.128.1 to 57.23.191.25457.23.191.25516,382
9657.23.192.0/1857.23.192.1 to 57.23.255.25457.23.255.25516,382
9757.24.0.0/1857.24.0.1 to 57.24.63.25457.24.63.25516,382
9857.24.64.0/1857.24.64.1 to 57.24.127.25457.24.127.25516,382
9957.24.128.0/1857.24.128.1 to 57.24.191.25457.24.191.25516,382
10057.24.192.0/1857.24.192.1 to 57.24.255.25457.24.255.25516,382
10157.25.0.0/1857.25.0.1 to 57.25.63.25457.25.63.25516,382
10257.25.64.0/1857.25.64.1 to 57.25.127.25457.25.127.25516,382
10357.25.128.0/1857.25.128.1 to 57.25.191.25457.25.191.25516,382
10457.25.192.0/1857.25.192.1 to 57.25.255.25457.25.255.25516,382
10557.26.0.0/1857.26.0.1 to 57.26.63.25457.26.63.25516,382
10657.26.64.0/1857.26.64.1 to 57.26.127.25457.26.127.25516,382
10757.26.128.0/1857.26.128.1 to 57.26.191.25457.26.191.25516,382
10857.26.192.0/1857.26.192.1 to 57.26.255.25457.26.255.25516,382
10957.27.0.0/1857.27.0.1 to 57.27.63.25457.27.63.25516,382
11057.27.64.0/1857.27.64.1 to 57.27.127.25457.27.127.25516,382
11157.27.128.0/1857.27.128.1 to 57.27.191.25457.27.191.25516,382
11257.27.192.0/1857.27.192.1 to 57.27.255.25457.27.255.25516,382
11357.28.0.0/1857.28.0.1 to 57.28.63.25457.28.63.25516,382
11457.28.64.0/1857.28.64.1 to 57.28.127.25457.28.127.25516,382
11557.28.128.0/1857.28.128.1 to 57.28.191.25457.28.191.25516,382
11657.28.192.0/1857.28.192.1 to 57.28.255.25457.28.255.25516,382
11757.29.0.0/1857.29.0.1 to 57.29.63.25457.29.63.25516,382
11857.29.64.0/1857.29.64.1 to 57.29.127.25457.29.127.25516,382
11957.29.128.0/1857.29.128.1 to 57.29.191.25457.29.191.25516,382
12057.29.192.0/1857.29.192.1 to 57.29.255.25457.29.255.25516,382
12157.30.0.0/1857.30.0.1 to 57.30.63.25457.30.63.25516,382
12257.30.64.0/1857.30.64.1 to 57.30.127.25457.30.127.25516,382
12357.30.128.0/1857.30.128.1 to 57.30.191.25457.30.191.25516,382
12457.30.192.0/1857.30.192.1 to 57.30.255.25457.30.255.25516,382
12557.31.0.0/1857.31.0.1 to 57.31.63.25457.31.63.25516,382
12657.31.64.0/1857.31.64.1 to 57.31.127.25457.31.127.25516,382
12757.31.128.0/1857.31.128.1 to 57.31.191.25457.31.191.25516,382
12857.31.192.0/1857.31.192.1 to 57.31.255.25457.31.255.25516,382
12957.32.0.0/1857.32.0.1 to 57.32.63.25457.32.63.25516,382
13057.32.64.0/1857.32.64.1 to 57.32.127.25457.32.127.25516,382
13157.32.128.0/1857.32.128.1 to 57.32.191.25457.32.191.25516,382
13257.32.192.0/1857.32.192.1 to 57.32.255.25457.32.255.25516,382
13357.33.0.0/1857.33.0.1 to 57.33.63.25457.33.63.25516,382
13457.33.64.0/1857.33.64.1 to 57.33.127.25457.33.127.25516,382
13557.33.128.0/1857.33.128.1 to 57.33.191.25457.33.191.25516,382
13657.33.192.0/1857.33.192.1 to 57.33.255.25457.33.255.25516,382
13757.34.0.0/1857.34.0.1 to 57.34.63.25457.34.63.25516,382
13857.34.64.0/1857.34.64.1 to 57.34.127.25457.34.127.25516,382
13957.34.128.0/1857.34.128.1 to 57.34.191.25457.34.191.25516,382
14057.34.192.0/1857.34.192.1 to 57.34.255.25457.34.255.25516,382
14157.35.0.0/1857.35.0.1 to 57.35.63.25457.35.63.25516,382
14257.35.64.0/1857.35.64.1 to 57.35.127.25457.35.127.25516,382
14357.35.128.0/1857.35.128.1 to 57.35.191.25457.35.191.25516,382
14457.35.192.0/1857.35.192.1 to 57.35.255.25457.35.255.25516,382
14557.36.0.0/1857.36.0.1 to 57.36.63.25457.36.63.25516,382
14657.36.64.0/1857.36.64.1 to 57.36.127.25457.36.127.25516,382
14757.36.128.0/1857.36.128.1 to 57.36.191.25457.36.191.25516,382
14857.36.192.0/1857.36.192.1 to 57.36.255.25457.36.255.25516,382
14957.37.0.0/1857.37.0.1 to 57.37.63.25457.37.63.25516,382
15057.37.64.0/1857.37.64.1 to 57.37.127.25457.37.127.25516,382
15157.37.128.0/1857.37.128.1 to 57.37.191.25457.37.191.25516,382
15257.37.192.0/1857.37.192.1 to 57.37.255.25457.37.255.25516,382
15357.38.0.0/1857.38.0.1 to 57.38.63.25457.38.63.25516,382
15457.38.64.0/1857.38.64.1 to 57.38.127.25457.38.127.25516,382
15557.38.128.0/1857.38.128.1 to 57.38.191.25457.38.191.25516,382
15657.38.192.0/1857.38.192.1 to 57.38.255.25457.38.255.25516,382
15757.39.0.0/1857.39.0.1 to 57.39.63.25457.39.63.25516,382
15857.39.64.0/1857.39.64.1 to 57.39.127.25457.39.127.25516,382
15957.39.128.0/1857.39.128.1 to 57.39.191.25457.39.191.25516,382
16057.39.192.0/1857.39.192.1 to 57.39.255.25457.39.255.25516,382
16157.40.0.0/1857.40.0.1 to 57.40.63.25457.40.63.25516,382
16257.40.64.0/1857.40.64.1 to 57.40.127.25457.40.127.25516,382
16357.40.128.0/1857.40.128.1 to 57.40.191.25457.40.191.25516,382
16457.40.192.0/1857.40.192.1 to 57.40.255.25457.40.255.25516,382
16557.41.0.0/1857.41.0.1 to 57.41.63.25457.41.63.25516,382
16657.41.64.0/1857.41.64.1 to 57.41.127.25457.41.127.25516,382
16757.41.128.0/1857.41.128.1 to 57.41.191.25457.41.191.25516,382
16857.41.192.0/1857.41.192.1 to 57.41.255.25457.41.255.25516,382
16957.42.0.0/1857.42.0.1 to 57.42.63.25457.42.63.25516,382
17057.42.64.0/1857.42.64.1 to 57.42.127.25457.42.127.25516,382
17157.42.128.0/1857.42.128.1 to 57.42.191.25457.42.191.25516,382
17257.42.192.0/1857.42.192.1 to 57.42.255.25457.42.255.25516,382
17357.43.0.0/1857.43.0.1 to 57.43.63.25457.43.63.25516,382
17457.43.64.0/1857.43.64.1 to 57.43.127.25457.43.127.25516,382
17557.43.128.0/1857.43.128.1 to 57.43.191.25457.43.191.25516,382
17657.43.192.0/1857.43.192.1 to 57.43.255.25457.43.255.25516,382
17757.44.0.0/1857.44.0.1 to 57.44.63.25457.44.63.25516,382
17857.44.64.0/1857.44.64.1 to 57.44.127.25457.44.127.25516,382
17957.44.128.0/1857.44.128.1 to 57.44.191.25457.44.191.25516,382
18057.44.192.0/1857.44.192.1 to 57.44.255.25457.44.255.25516,382
18157.45.0.0/1857.45.0.1 to 57.45.63.25457.45.63.25516,382
18257.45.64.0/1857.45.64.1 to 57.45.127.25457.45.127.25516,382
18357.45.128.0/1857.45.128.1 to 57.45.191.25457.45.191.25516,382
18457.45.192.0/1857.45.192.1 to 57.45.255.25457.45.255.25516,382
18557.46.0.0/1857.46.0.1 to 57.46.63.25457.46.63.25516,382
18657.46.64.0/1857.46.64.1 to 57.46.127.25457.46.127.25516,382
18757.46.128.0/1857.46.128.1 to 57.46.191.25457.46.191.25516,382
18857.46.192.0/1857.46.192.1 to 57.46.255.25457.46.255.25516,382
18957.47.0.0/1857.47.0.1 to 57.47.63.25457.47.63.25516,382
19057.47.64.0/1857.47.64.1 to 57.47.127.25457.47.127.25516,382
19157.47.128.0/1857.47.128.1 to 57.47.191.25457.47.191.25516,382
19257.47.192.0/1857.47.192.1 to 57.47.255.25457.47.255.25516,382
19357.48.0.0/1857.48.0.1 to 57.48.63.25457.48.63.25516,382
19457.48.64.0/1857.48.64.1 to 57.48.127.25457.48.127.25516,382
19557.48.128.0/1857.48.128.1 to 57.48.191.25457.48.191.25516,382
19657.48.192.0/1857.48.192.1 to 57.48.255.25457.48.255.25516,382
19757.49.0.0/1857.49.0.1 to 57.49.63.25457.49.63.25516,382
19857.49.64.0/1857.49.64.1 to 57.49.127.25457.49.127.25516,382
19957.49.128.0/1857.49.128.1 to 57.49.191.25457.49.191.25516,382
20057.49.192.0/1857.49.192.1 to 57.49.255.25457.49.255.25516,382
20157.50.0.0/1857.50.0.1 to 57.50.63.25457.50.63.25516,382
20257.50.64.0/1857.50.64.1 to 57.50.127.25457.50.127.25516,382
20357.50.128.0/1857.50.128.1 to 57.50.191.25457.50.191.25516,382
20457.50.192.0/1857.50.192.1 to 57.50.255.25457.50.255.25516,382
20557.51.0.0/1857.51.0.1 to 57.51.63.25457.51.63.25516,382
20657.51.64.0/1857.51.64.1 to 57.51.127.25457.51.127.25516,382
20757.51.128.0/1857.51.128.1 to 57.51.191.25457.51.191.25516,382
20857.51.192.0/1857.51.192.1 to 57.51.255.25457.51.255.25516,382
20957.52.0.0/1857.52.0.1 to 57.52.63.25457.52.63.25516,382
21057.52.64.0/1857.52.64.1 to 57.52.127.25457.52.127.25516,382
21157.52.128.0/1857.52.128.1 to 57.52.191.25457.52.191.25516,382
21257.52.192.0/1857.52.192.1 to 57.52.255.25457.52.255.25516,382
21357.53.0.0/1857.53.0.1 to 57.53.63.25457.53.63.25516,382
21457.53.64.0/1857.53.64.1 to 57.53.127.25457.53.127.25516,382
21557.53.128.0/1857.53.128.1 to 57.53.191.25457.53.191.25516,382
21657.53.192.0/1857.53.192.1 to 57.53.255.25457.53.255.25516,382
21757.54.0.0/1857.54.0.1 to 57.54.63.25457.54.63.25516,382
21857.54.64.0/1857.54.64.1 to 57.54.127.25457.54.127.25516,382
21957.54.128.0/1857.54.128.1 to 57.54.191.25457.54.191.25516,382
22057.54.192.0/1857.54.192.1 to 57.54.255.25457.54.255.25516,382
22157.55.0.0/1857.55.0.1 to 57.55.63.25457.55.63.25516,382
22257.55.64.0/1857.55.64.1 to 57.55.127.25457.55.127.25516,382
22357.55.128.0/1857.55.128.1 to 57.55.191.25457.55.191.25516,382
22457.55.192.0/1857.55.192.1 to 57.55.255.25457.55.255.25516,382
22557.56.0.0/1857.56.0.1 to 57.56.63.25457.56.63.25516,382
22657.56.64.0/1857.56.64.1 to 57.56.127.25457.56.127.25516,382
22757.56.128.0/1857.56.128.1 to 57.56.191.25457.56.191.25516,382
22857.56.192.0/1857.56.192.1 to 57.56.255.25457.56.255.25516,382
22957.57.0.0/1857.57.0.1 to 57.57.63.25457.57.63.25516,382
23057.57.64.0/1857.57.64.1 to 57.57.127.25457.57.127.25516,382
23157.57.128.0/1857.57.128.1 to 57.57.191.25457.57.191.25516,382
23257.57.192.0/1857.57.192.1 to 57.57.255.25457.57.255.25516,382
23357.58.0.0/1857.58.0.1 to 57.58.63.25457.58.63.25516,382
23457.58.64.0/1857.58.64.1 to 57.58.127.25457.58.127.25516,382
23557.58.128.0/1857.58.128.1 to 57.58.191.25457.58.191.25516,382
23657.58.192.0/1857.58.192.1 to 57.58.255.25457.58.255.25516,382
23757.59.0.0/1857.59.0.1 to 57.59.63.25457.59.63.25516,382
23857.59.64.0/1857.59.64.1 to 57.59.127.25457.59.127.25516,382
23957.59.128.0/1857.59.128.1 to 57.59.191.25457.59.191.25516,382
24057.59.192.0/1857.59.192.1 to 57.59.255.25457.59.255.25516,382
24157.60.0.0/1857.60.0.1 to 57.60.63.25457.60.63.25516,382
24257.60.64.0/1857.60.64.1 to 57.60.127.25457.60.127.25516,382
24357.60.128.0/1857.60.128.1 to 57.60.191.25457.60.191.25516,382
24457.60.192.0/1857.60.192.1 to 57.60.255.25457.60.255.25516,382
24557.61.0.0/1857.61.0.1 to 57.61.63.25457.61.63.25516,382
24657.61.64.0/1857.61.64.1 to 57.61.127.25457.61.127.25516,382
24757.61.128.0/1857.61.128.1 to 57.61.191.25457.61.191.25516,382
24857.61.192.0/1857.61.192.1 to 57.61.255.25457.61.255.25516,382
24957.62.0.0/1857.62.0.1 to 57.62.63.25457.62.63.25516,382
25057.62.64.0/1857.62.64.1 to 57.62.127.25457.62.127.25516,382
25157.62.128.0/1857.62.128.1 to 57.62.191.25457.62.191.25516,382
25257.62.192.0/1857.62.192.1 to 57.62.255.25457.62.255.25516,382
25357.63.0.0/1857.63.0.1 to 57.63.63.25457.63.63.25516,382
25457.63.64.0/1857.63.64.1 to 57.63.127.25457.63.127.25516,382
25557.63.128.0/1857.63.128.1 to 57.63.191.25457.63.191.25516,382
25657.63.192.0/1857.63.192.1 to 57.63.255.25457.63.255.25516,382

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.