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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.

Network54.78.0.0/17
Usable hosts32,766
Subnet mask255.255.128.0
Addresses32,768
Network address
54.78.0.0
Broadcast address
54.78.127.255
First usable
54.78.0.1
Last usable
54.78.127.254
Usable hosts
32,766 (32,768 less the network and broadcast addresses)
Subnet mask
255.255.128.0
Wildcard mask
0.0.127.255 (Cisco ACLs, OSPF)
Prefix length
/17
Type
Public public
Old class
A (default /8)
As numbers
Hex 364E0000 · Integer 911081472 to 911114239
Reverse DNS zones
0.78.54.in-addr.arpa
1.78.54.in-addr.arpa
2.78.54.in-addr.arpa
3.78.54.in-addr.arpa
4.78.54.in-addr.arpa
5.78.54.in-addr.arpa
6.78.54.in-addr.arpa
7.78.54.in-addr.arpa
8.78.54.in-addr.arpa
9.78.54.in-addr.arpa
10.78.54.in-addr.arpa
11.78.54.in-addr.arpa
12.78.54.in-addr.arpa
13.78.54.in-addr.arpa
14.78.54.in-addr.arpa
15.78.54.in-addr.arpa
and 112 more
/17 is not on a 8-bit boundary, so it takes 128 /24 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address00110110.01001110.00000000.0000000054.78.0.0
Subnet mask11111111.11111111.10000000.00000000255.255.128.0
Network00110110.01001110.00000000.0000000054.78.0.0
Broadcast00110110.01001110.01111111.1111111154.78.127.255
Split into smaller subnets/25
/18 (2)/19 (4)/20 (8)/21 (16)/22 (32)/23 (64)/24 (128)/25 (256)/26 (512)/27 (1,024)/28 (2,048)/29 (4,096)

54.78.0.0/17 makes 256 subnets of /25.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
154.78.0.0/2554.78.0.1 to 54.78.0.12654.78.0.127126
254.78.0.128/2554.78.0.129 to 54.78.0.25454.78.0.255126
354.78.1.0/2554.78.1.1 to 54.78.1.12654.78.1.127126
454.78.1.128/2554.78.1.129 to 54.78.1.25454.78.1.255126
554.78.2.0/2554.78.2.1 to 54.78.2.12654.78.2.127126
654.78.2.128/2554.78.2.129 to 54.78.2.25454.78.2.255126
754.78.3.0/2554.78.3.1 to 54.78.3.12654.78.3.127126
854.78.3.128/2554.78.3.129 to 54.78.3.25454.78.3.255126
954.78.4.0/2554.78.4.1 to 54.78.4.12654.78.4.127126
1054.78.4.128/2554.78.4.129 to 54.78.4.25454.78.4.255126
1154.78.5.0/2554.78.5.1 to 54.78.5.12654.78.5.127126
1254.78.5.128/2554.78.5.129 to 54.78.5.25454.78.5.255126
1354.78.6.0/2554.78.6.1 to 54.78.6.12654.78.6.127126
1454.78.6.128/2554.78.6.129 to 54.78.6.25454.78.6.255126
1554.78.7.0/2554.78.7.1 to 54.78.7.12654.78.7.127126
1654.78.7.128/2554.78.7.129 to 54.78.7.25454.78.7.255126
1754.78.8.0/2554.78.8.1 to 54.78.8.12654.78.8.127126
1854.78.8.128/2554.78.8.129 to 54.78.8.25454.78.8.255126
1954.78.9.0/2554.78.9.1 to 54.78.9.12654.78.9.127126
2054.78.9.128/2554.78.9.129 to 54.78.9.25454.78.9.255126
2154.78.10.0/2554.78.10.1 to 54.78.10.12654.78.10.127126
2254.78.10.128/2554.78.10.129 to 54.78.10.25454.78.10.255126
2354.78.11.0/2554.78.11.1 to 54.78.11.12654.78.11.127126
2454.78.11.128/2554.78.11.129 to 54.78.11.25454.78.11.255126
2554.78.12.0/2554.78.12.1 to 54.78.12.12654.78.12.127126
2654.78.12.128/2554.78.12.129 to 54.78.12.25454.78.12.255126
2754.78.13.0/2554.78.13.1 to 54.78.13.12654.78.13.127126
2854.78.13.128/2554.78.13.129 to 54.78.13.25454.78.13.255126
2954.78.14.0/2554.78.14.1 to 54.78.14.12654.78.14.127126
3054.78.14.128/2554.78.14.129 to 54.78.14.25454.78.14.255126
3154.78.15.0/2554.78.15.1 to 54.78.15.12654.78.15.127126
3254.78.15.128/2554.78.15.129 to 54.78.15.25454.78.15.255126
3354.78.16.0/2554.78.16.1 to 54.78.16.12654.78.16.127126
3454.78.16.128/2554.78.16.129 to 54.78.16.25454.78.16.255126
3554.78.17.0/2554.78.17.1 to 54.78.17.12654.78.17.127126
3654.78.17.128/2554.78.17.129 to 54.78.17.25454.78.17.255126
3754.78.18.0/2554.78.18.1 to 54.78.18.12654.78.18.127126
3854.78.18.128/2554.78.18.129 to 54.78.18.25454.78.18.255126
3954.78.19.0/2554.78.19.1 to 54.78.19.12654.78.19.127126
4054.78.19.128/2554.78.19.129 to 54.78.19.25454.78.19.255126
4154.78.20.0/2554.78.20.1 to 54.78.20.12654.78.20.127126
4254.78.20.128/2554.78.20.129 to 54.78.20.25454.78.20.255126
4354.78.21.0/2554.78.21.1 to 54.78.21.12654.78.21.127126
4454.78.21.128/2554.78.21.129 to 54.78.21.25454.78.21.255126
4554.78.22.0/2554.78.22.1 to 54.78.22.12654.78.22.127126
4654.78.22.128/2554.78.22.129 to 54.78.22.25454.78.22.255126
4754.78.23.0/2554.78.23.1 to 54.78.23.12654.78.23.127126
4854.78.23.128/2554.78.23.129 to 54.78.23.25454.78.23.255126
4954.78.24.0/2554.78.24.1 to 54.78.24.12654.78.24.127126
5054.78.24.128/2554.78.24.129 to 54.78.24.25454.78.24.255126
5154.78.25.0/2554.78.25.1 to 54.78.25.12654.78.25.127126
5254.78.25.128/2554.78.25.129 to 54.78.25.25454.78.25.255126
5354.78.26.0/2554.78.26.1 to 54.78.26.12654.78.26.127126
5454.78.26.128/2554.78.26.129 to 54.78.26.25454.78.26.255126
5554.78.27.0/2554.78.27.1 to 54.78.27.12654.78.27.127126
5654.78.27.128/2554.78.27.129 to 54.78.27.25454.78.27.255126
5754.78.28.0/2554.78.28.1 to 54.78.28.12654.78.28.127126
5854.78.28.128/2554.78.28.129 to 54.78.28.25454.78.28.255126
5954.78.29.0/2554.78.29.1 to 54.78.29.12654.78.29.127126
6054.78.29.128/2554.78.29.129 to 54.78.29.25454.78.29.255126
6154.78.30.0/2554.78.30.1 to 54.78.30.12654.78.30.127126
6254.78.30.128/2554.78.30.129 to 54.78.30.25454.78.30.255126
6354.78.31.0/2554.78.31.1 to 54.78.31.12654.78.31.127126
6454.78.31.128/2554.78.31.129 to 54.78.31.25454.78.31.255126
6554.78.32.0/2554.78.32.1 to 54.78.32.12654.78.32.127126
6654.78.32.128/2554.78.32.129 to 54.78.32.25454.78.32.255126
6754.78.33.0/2554.78.33.1 to 54.78.33.12654.78.33.127126
6854.78.33.128/2554.78.33.129 to 54.78.33.25454.78.33.255126
6954.78.34.0/2554.78.34.1 to 54.78.34.12654.78.34.127126
7054.78.34.128/2554.78.34.129 to 54.78.34.25454.78.34.255126
7154.78.35.0/2554.78.35.1 to 54.78.35.12654.78.35.127126
7254.78.35.128/2554.78.35.129 to 54.78.35.25454.78.35.255126
7354.78.36.0/2554.78.36.1 to 54.78.36.12654.78.36.127126
7454.78.36.128/2554.78.36.129 to 54.78.36.25454.78.36.255126
7554.78.37.0/2554.78.37.1 to 54.78.37.12654.78.37.127126
7654.78.37.128/2554.78.37.129 to 54.78.37.25454.78.37.255126
7754.78.38.0/2554.78.38.1 to 54.78.38.12654.78.38.127126
7854.78.38.128/2554.78.38.129 to 54.78.38.25454.78.38.255126
7954.78.39.0/2554.78.39.1 to 54.78.39.12654.78.39.127126
8054.78.39.128/2554.78.39.129 to 54.78.39.25454.78.39.255126
8154.78.40.0/2554.78.40.1 to 54.78.40.12654.78.40.127126
8254.78.40.128/2554.78.40.129 to 54.78.40.25454.78.40.255126
8354.78.41.0/2554.78.41.1 to 54.78.41.12654.78.41.127126
8454.78.41.128/2554.78.41.129 to 54.78.41.25454.78.41.255126
8554.78.42.0/2554.78.42.1 to 54.78.42.12654.78.42.127126
8654.78.42.128/2554.78.42.129 to 54.78.42.25454.78.42.255126
8754.78.43.0/2554.78.43.1 to 54.78.43.12654.78.43.127126
8854.78.43.128/2554.78.43.129 to 54.78.43.25454.78.43.255126
8954.78.44.0/2554.78.44.1 to 54.78.44.12654.78.44.127126
9054.78.44.128/2554.78.44.129 to 54.78.44.25454.78.44.255126
9154.78.45.0/2554.78.45.1 to 54.78.45.12654.78.45.127126
9254.78.45.128/2554.78.45.129 to 54.78.45.25454.78.45.255126
9354.78.46.0/2554.78.46.1 to 54.78.46.12654.78.46.127126
9454.78.46.128/2554.78.46.129 to 54.78.46.25454.78.46.255126
9554.78.47.0/2554.78.47.1 to 54.78.47.12654.78.47.127126
9654.78.47.128/2554.78.47.129 to 54.78.47.25454.78.47.255126
9754.78.48.0/2554.78.48.1 to 54.78.48.12654.78.48.127126
9854.78.48.128/2554.78.48.129 to 54.78.48.25454.78.48.255126
9954.78.49.0/2554.78.49.1 to 54.78.49.12654.78.49.127126
10054.78.49.128/2554.78.49.129 to 54.78.49.25454.78.49.255126
10154.78.50.0/2554.78.50.1 to 54.78.50.12654.78.50.127126
10254.78.50.128/2554.78.50.129 to 54.78.50.25454.78.50.255126
10354.78.51.0/2554.78.51.1 to 54.78.51.12654.78.51.127126
10454.78.51.128/2554.78.51.129 to 54.78.51.25454.78.51.255126
10554.78.52.0/2554.78.52.1 to 54.78.52.12654.78.52.127126
10654.78.52.128/2554.78.52.129 to 54.78.52.25454.78.52.255126
10754.78.53.0/2554.78.53.1 to 54.78.53.12654.78.53.127126
10854.78.53.128/2554.78.53.129 to 54.78.53.25454.78.53.255126
10954.78.54.0/2554.78.54.1 to 54.78.54.12654.78.54.127126
11054.78.54.128/2554.78.54.129 to 54.78.54.25454.78.54.255126
11154.78.55.0/2554.78.55.1 to 54.78.55.12654.78.55.127126
11254.78.55.128/2554.78.55.129 to 54.78.55.25454.78.55.255126
11354.78.56.0/2554.78.56.1 to 54.78.56.12654.78.56.127126
11454.78.56.128/2554.78.56.129 to 54.78.56.25454.78.56.255126
11554.78.57.0/2554.78.57.1 to 54.78.57.12654.78.57.127126
11654.78.57.128/2554.78.57.129 to 54.78.57.25454.78.57.255126
11754.78.58.0/2554.78.58.1 to 54.78.58.12654.78.58.127126
11854.78.58.128/2554.78.58.129 to 54.78.58.25454.78.58.255126
11954.78.59.0/2554.78.59.1 to 54.78.59.12654.78.59.127126
12054.78.59.128/2554.78.59.129 to 54.78.59.25454.78.59.255126
12154.78.60.0/2554.78.60.1 to 54.78.60.12654.78.60.127126
12254.78.60.128/2554.78.60.129 to 54.78.60.25454.78.60.255126
12354.78.61.0/2554.78.61.1 to 54.78.61.12654.78.61.127126
12454.78.61.128/2554.78.61.129 to 54.78.61.25454.78.61.255126
12554.78.62.0/2554.78.62.1 to 54.78.62.12654.78.62.127126
12654.78.62.128/2554.78.62.129 to 54.78.62.25454.78.62.255126
12754.78.63.0/2554.78.63.1 to 54.78.63.12654.78.63.127126
12854.78.63.128/2554.78.63.129 to 54.78.63.25454.78.63.255126
12954.78.64.0/2554.78.64.1 to 54.78.64.12654.78.64.127126
13054.78.64.128/2554.78.64.129 to 54.78.64.25454.78.64.255126
13154.78.65.0/2554.78.65.1 to 54.78.65.12654.78.65.127126
13254.78.65.128/2554.78.65.129 to 54.78.65.25454.78.65.255126
13354.78.66.0/2554.78.66.1 to 54.78.66.12654.78.66.127126
13454.78.66.128/2554.78.66.129 to 54.78.66.25454.78.66.255126
13554.78.67.0/2554.78.67.1 to 54.78.67.12654.78.67.127126
13654.78.67.128/2554.78.67.129 to 54.78.67.25454.78.67.255126
13754.78.68.0/2554.78.68.1 to 54.78.68.12654.78.68.127126
13854.78.68.128/2554.78.68.129 to 54.78.68.25454.78.68.255126
13954.78.69.0/2554.78.69.1 to 54.78.69.12654.78.69.127126
14054.78.69.128/2554.78.69.129 to 54.78.69.25454.78.69.255126
14154.78.70.0/2554.78.70.1 to 54.78.70.12654.78.70.127126
14254.78.70.128/2554.78.70.129 to 54.78.70.25454.78.70.255126
14354.78.71.0/2554.78.71.1 to 54.78.71.12654.78.71.127126
14454.78.71.128/2554.78.71.129 to 54.78.71.25454.78.71.255126
14554.78.72.0/2554.78.72.1 to 54.78.72.12654.78.72.127126
14654.78.72.128/2554.78.72.129 to 54.78.72.25454.78.72.255126
14754.78.73.0/2554.78.73.1 to 54.78.73.12654.78.73.127126
14854.78.73.128/2554.78.73.129 to 54.78.73.25454.78.73.255126
14954.78.74.0/2554.78.74.1 to 54.78.74.12654.78.74.127126
15054.78.74.128/2554.78.74.129 to 54.78.74.25454.78.74.255126
15154.78.75.0/2554.78.75.1 to 54.78.75.12654.78.75.127126
15254.78.75.128/2554.78.75.129 to 54.78.75.25454.78.75.255126
15354.78.76.0/2554.78.76.1 to 54.78.76.12654.78.76.127126
15454.78.76.128/2554.78.76.129 to 54.78.76.25454.78.76.255126
15554.78.77.0/2554.78.77.1 to 54.78.77.12654.78.77.127126
15654.78.77.128/2554.78.77.129 to 54.78.77.25454.78.77.255126
15754.78.78.0/2554.78.78.1 to 54.78.78.12654.78.78.127126
15854.78.78.128/2554.78.78.129 to 54.78.78.25454.78.78.255126
15954.78.79.0/2554.78.79.1 to 54.78.79.12654.78.79.127126
16054.78.79.128/2554.78.79.129 to 54.78.79.25454.78.79.255126
16154.78.80.0/2554.78.80.1 to 54.78.80.12654.78.80.127126
16254.78.80.128/2554.78.80.129 to 54.78.80.25454.78.80.255126
16354.78.81.0/2554.78.81.1 to 54.78.81.12654.78.81.127126
16454.78.81.128/2554.78.81.129 to 54.78.81.25454.78.81.255126
16554.78.82.0/2554.78.82.1 to 54.78.82.12654.78.82.127126
16654.78.82.128/2554.78.82.129 to 54.78.82.25454.78.82.255126
16754.78.83.0/2554.78.83.1 to 54.78.83.12654.78.83.127126
16854.78.83.128/2554.78.83.129 to 54.78.83.25454.78.83.255126
16954.78.84.0/2554.78.84.1 to 54.78.84.12654.78.84.127126
17054.78.84.128/2554.78.84.129 to 54.78.84.25454.78.84.255126
17154.78.85.0/2554.78.85.1 to 54.78.85.12654.78.85.127126
17254.78.85.128/2554.78.85.129 to 54.78.85.25454.78.85.255126
17354.78.86.0/2554.78.86.1 to 54.78.86.12654.78.86.127126
17454.78.86.128/2554.78.86.129 to 54.78.86.25454.78.86.255126
17554.78.87.0/2554.78.87.1 to 54.78.87.12654.78.87.127126
17654.78.87.128/2554.78.87.129 to 54.78.87.25454.78.87.255126
17754.78.88.0/2554.78.88.1 to 54.78.88.12654.78.88.127126
17854.78.88.128/2554.78.88.129 to 54.78.88.25454.78.88.255126
17954.78.89.0/2554.78.89.1 to 54.78.89.12654.78.89.127126
18054.78.89.128/2554.78.89.129 to 54.78.89.25454.78.89.255126
18154.78.90.0/2554.78.90.1 to 54.78.90.12654.78.90.127126
18254.78.90.128/2554.78.90.129 to 54.78.90.25454.78.90.255126
18354.78.91.0/2554.78.91.1 to 54.78.91.12654.78.91.127126
18454.78.91.128/2554.78.91.129 to 54.78.91.25454.78.91.255126
18554.78.92.0/2554.78.92.1 to 54.78.92.12654.78.92.127126
18654.78.92.128/2554.78.92.129 to 54.78.92.25454.78.92.255126
18754.78.93.0/2554.78.93.1 to 54.78.93.12654.78.93.127126
18854.78.93.128/2554.78.93.129 to 54.78.93.25454.78.93.255126
18954.78.94.0/2554.78.94.1 to 54.78.94.12654.78.94.127126
19054.78.94.128/2554.78.94.129 to 54.78.94.25454.78.94.255126
19154.78.95.0/2554.78.95.1 to 54.78.95.12654.78.95.127126
19254.78.95.128/2554.78.95.129 to 54.78.95.25454.78.95.255126
19354.78.96.0/2554.78.96.1 to 54.78.96.12654.78.96.127126
19454.78.96.128/2554.78.96.129 to 54.78.96.25454.78.96.255126
19554.78.97.0/2554.78.97.1 to 54.78.97.12654.78.97.127126
19654.78.97.128/2554.78.97.129 to 54.78.97.25454.78.97.255126
19754.78.98.0/2554.78.98.1 to 54.78.98.12654.78.98.127126
19854.78.98.128/2554.78.98.129 to 54.78.98.25454.78.98.255126
19954.78.99.0/2554.78.99.1 to 54.78.99.12654.78.99.127126
20054.78.99.128/2554.78.99.129 to 54.78.99.25454.78.99.255126
20154.78.100.0/2554.78.100.1 to 54.78.100.12654.78.100.127126
20254.78.100.128/2554.78.100.129 to 54.78.100.25454.78.100.255126
20354.78.101.0/2554.78.101.1 to 54.78.101.12654.78.101.127126
20454.78.101.128/2554.78.101.129 to 54.78.101.25454.78.101.255126
20554.78.102.0/2554.78.102.1 to 54.78.102.12654.78.102.127126
20654.78.102.128/2554.78.102.129 to 54.78.102.25454.78.102.255126
20754.78.103.0/2554.78.103.1 to 54.78.103.12654.78.103.127126
20854.78.103.128/2554.78.103.129 to 54.78.103.25454.78.103.255126
20954.78.104.0/2554.78.104.1 to 54.78.104.12654.78.104.127126
21054.78.104.128/2554.78.104.129 to 54.78.104.25454.78.104.255126
21154.78.105.0/2554.78.105.1 to 54.78.105.12654.78.105.127126
21254.78.105.128/2554.78.105.129 to 54.78.105.25454.78.105.255126
21354.78.106.0/2554.78.106.1 to 54.78.106.12654.78.106.127126
21454.78.106.128/2554.78.106.129 to 54.78.106.25454.78.106.255126
21554.78.107.0/2554.78.107.1 to 54.78.107.12654.78.107.127126
21654.78.107.128/2554.78.107.129 to 54.78.107.25454.78.107.255126
21754.78.108.0/2554.78.108.1 to 54.78.108.12654.78.108.127126
21854.78.108.128/2554.78.108.129 to 54.78.108.25454.78.108.255126
21954.78.109.0/2554.78.109.1 to 54.78.109.12654.78.109.127126
22054.78.109.128/2554.78.109.129 to 54.78.109.25454.78.109.255126
22154.78.110.0/2554.78.110.1 to 54.78.110.12654.78.110.127126
22254.78.110.128/2554.78.110.129 to 54.78.110.25454.78.110.255126
22354.78.111.0/2554.78.111.1 to 54.78.111.12654.78.111.127126
22454.78.111.128/2554.78.111.129 to 54.78.111.25454.78.111.255126
22554.78.112.0/2554.78.112.1 to 54.78.112.12654.78.112.127126
22654.78.112.128/2554.78.112.129 to 54.78.112.25454.78.112.255126
22754.78.113.0/2554.78.113.1 to 54.78.113.12654.78.113.127126
22854.78.113.128/2554.78.113.129 to 54.78.113.25454.78.113.255126
22954.78.114.0/2554.78.114.1 to 54.78.114.12654.78.114.127126
23054.78.114.128/2554.78.114.129 to 54.78.114.25454.78.114.255126
23154.78.115.0/2554.78.115.1 to 54.78.115.12654.78.115.127126
23254.78.115.128/2554.78.115.129 to 54.78.115.25454.78.115.255126
23354.78.116.0/2554.78.116.1 to 54.78.116.12654.78.116.127126
23454.78.116.128/2554.78.116.129 to 54.78.116.25454.78.116.255126
23554.78.117.0/2554.78.117.1 to 54.78.117.12654.78.117.127126
23654.78.117.128/2554.78.117.129 to 54.78.117.25454.78.117.255126
23754.78.118.0/2554.78.118.1 to 54.78.118.12654.78.118.127126
23854.78.118.128/2554.78.118.129 to 54.78.118.25454.78.118.255126
23954.78.119.0/2554.78.119.1 to 54.78.119.12654.78.119.127126
24054.78.119.128/2554.78.119.129 to 54.78.119.25454.78.119.255126
24154.78.120.0/2554.78.120.1 to 54.78.120.12654.78.120.127126
24254.78.120.128/2554.78.120.129 to 54.78.120.25454.78.120.255126
24354.78.121.0/2554.78.121.1 to 54.78.121.12654.78.121.127126
24454.78.121.128/2554.78.121.129 to 54.78.121.25454.78.121.255126
24554.78.122.0/2554.78.122.1 to 54.78.122.12654.78.122.127126
24654.78.122.128/2554.78.122.129 to 54.78.122.25454.78.122.255126
24754.78.123.0/2554.78.123.1 to 54.78.123.12654.78.123.127126
24854.78.123.128/2554.78.123.129 to 54.78.123.25454.78.123.255126
24954.78.124.0/2554.78.124.1 to 54.78.124.12654.78.124.127126
25054.78.124.128/2554.78.124.129 to 54.78.124.25454.78.124.255126
25154.78.125.0/2554.78.125.1 to 54.78.125.12654.78.125.127126
25254.78.125.128/2554.78.125.129 to 54.78.125.25454.78.125.255126
25354.78.126.0/2554.78.126.1 to 54.78.126.12654.78.126.127126
25454.78.126.128/2554.78.126.129 to 54.78.126.25454.78.126.255126
25554.78.127.0/2554.78.127.1 to 54.78.127.12654.78.127.127126
25654.78.127.128/2554.78.127.129 to 54.78.127.25454.78.127.255126

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.