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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.

Network70.0.0.0/9
Usable hosts8,388,606
Subnet mask255.128.0.0
Addresses8,388,608
Network address
70.0.0.0
Broadcast address
70.127.255.255
First usable
70.0.0.1
Last usable
70.127.255.254
Usable hosts
8,388,606 (8,388,608 less the network and broadcast addresses)
Subnet mask
255.128.0.0
Wildcard mask
0.127.255.255 (Cisco ACLs, OSPF)
Prefix length
/9
Type
Public public
Old class
A (default /8)
As numbers
Hex 46000000 · Integer 1174405120 to 1182793727
Reverse DNS zones
0.70.in-addr.arpa
1.70.in-addr.arpa
2.70.in-addr.arpa
3.70.in-addr.arpa
4.70.in-addr.arpa
5.70.in-addr.arpa
6.70.in-addr.arpa
7.70.in-addr.arpa
8.70.in-addr.arpa
9.70.in-addr.arpa
10.70.in-addr.arpa
11.70.in-addr.arpa
12.70.in-addr.arpa
13.70.in-addr.arpa
14.70.in-addr.arpa
15.70.in-addr.arpa
and 112 more
/9 is not on a 8-bit boundary, so it takes 128 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address01000110.00000000.00000000.0000000070.0.0.0
Subnet mask11111111.10000000.00000000.00000000255.128.0.0
Network01000110.00000000.00000000.0000000070.0.0.0
Broadcast01000110.01111111.11111111.1111111170.127.255.255
Split into smaller subnets/17
/10 (2)/11 (4)/12 (8)/13 (16)/14 (32)/15 (64)/16 (128)/17 (256)/18 (512)/19 (1,024)/20 (2,048)/21 (4,096)

70.0.0.0/9 makes 256 subnets of /17.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
170.0.0.0/1770.0.0.1 to 70.0.127.25470.0.127.25532,766
270.0.128.0/1770.0.128.1 to 70.0.255.25470.0.255.25532,766
370.1.0.0/1770.1.0.1 to 70.1.127.25470.1.127.25532,766
470.1.128.0/1770.1.128.1 to 70.1.255.25470.1.255.25532,766
570.2.0.0/1770.2.0.1 to 70.2.127.25470.2.127.25532,766
670.2.128.0/1770.2.128.1 to 70.2.255.25470.2.255.25532,766
770.3.0.0/1770.3.0.1 to 70.3.127.25470.3.127.25532,766
870.3.128.0/1770.3.128.1 to 70.3.255.25470.3.255.25532,766
970.4.0.0/1770.4.0.1 to 70.4.127.25470.4.127.25532,766
1070.4.128.0/1770.4.128.1 to 70.4.255.25470.4.255.25532,766
1170.5.0.0/1770.5.0.1 to 70.5.127.25470.5.127.25532,766
1270.5.128.0/1770.5.128.1 to 70.5.255.25470.5.255.25532,766
1370.6.0.0/1770.6.0.1 to 70.6.127.25470.6.127.25532,766
1470.6.128.0/1770.6.128.1 to 70.6.255.25470.6.255.25532,766
1570.7.0.0/1770.7.0.1 to 70.7.127.25470.7.127.25532,766
1670.7.128.0/1770.7.128.1 to 70.7.255.25470.7.255.25532,766
1770.8.0.0/1770.8.0.1 to 70.8.127.25470.8.127.25532,766
1870.8.128.0/1770.8.128.1 to 70.8.255.25470.8.255.25532,766
1970.9.0.0/1770.9.0.1 to 70.9.127.25470.9.127.25532,766
2070.9.128.0/1770.9.128.1 to 70.9.255.25470.9.255.25532,766
2170.10.0.0/1770.10.0.1 to 70.10.127.25470.10.127.25532,766
2270.10.128.0/1770.10.128.1 to 70.10.255.25470.10.255.25532,766
2370.11.0.0/1770.11.0.1 to 70.11.127.25470.11.127.25532,766
2470.11.128.0/1770.11.128.1 to 70.11.255.25470.11.255.25532,766
2570.12.0.0/1770.12.0.1 to 70.12.127.25470.12.127.25532,766
2670.12.128.0/1770.12.128.1 to 70.12.255.25470.12.255.25532,766
2770.13.0.0/1770.13.0.1 to 70.13.127.25470.13.127.25532,766
2870.13.128.0/1770.13.128.1 to 70.13.255.25470.13.255.25532,766
2970.14.0.0/1770.14.0.1 to 70.14.127.25470.14.127.25532,766
3070.14.128.0/1770.14.128.1 to 70.14.255.25470.14.255.25532,766
3170.15.0.0/1770.15.0.1 to 70.15.127.25470.15.127.25532,766
3270.15.128.0/1770.15.128.1 to 70.15.255.25470.15.255.25532,766
3370.16.0.0/1770.16.0.1 to 70.16.127.25470.16.127.25532,766
3470.16.128.0/1770.16.128.1 to 70.16.255.25470.16.255.25532,766
3570.17.0.0/1770.17.0.1 to 70.17.127.25470.17.127.25532,766
3670.17.128.0/1770.17.128.1 to 70.17.255.25470.17.255.25532,766
3770.18.0.0/1770.18.0.1 to 70.18.127.25470.18.127.25532,766
3870.18.128.0/1770.18.128.1 to 70.18.255.25470.18.255.25532,766
3970.19.0.0/1770.19.0.1 to 70.19.127.25470.19.127.25532,766
4070.19.128.0/1770.19.128.1 to 70.19.255.25470.19.255.25532,766
4170.20.0.0/1770.20.0.1 to 70.20.127.25470.20.127.25532,766
4270.20.128.0/1770.20.128.1 to 70.20.255.25470.20.255.25532,766
4370.21.0.0/1770.21.0.1 to 70.21.127.25470.21.127.25532,766
4470.21.128.0/1770.21.128.1 to 70.21.255.25470.21.255.25532,766
4570.22.0.0/1770.22.0.1 to 70.22.127.25470.22.127.25532,766
4670.22.128.0/1770.22.128.1 to 70.22.255.25470.22.255.25532,766
4770.23.0.0/1770.23.0.1 to 70.23.127.25470.23.127.25532,766
4870.23.128.0/1770.23.128.1 to 70.23.255.25470.23.255.25532,766
4970.24.0.0/1770.24.0.1 to 70.24.127.25470.24.127.25532,766
5070.24.128.0/1770.24.128.1 to 70.24.255.25470.24.255.25532,766
5170.25.0.0/1770.25.0.1 to 70.25.127.25470.25.127.25532,766
5270.25.128.0/1770.25.128.1 to 70.25.255.25470.25.255.25532,766
5370.26.0.0/1770.26.0.1 to 70.26.127.25470.26.127.25532,766
5470.26.128.0/1770.26.128.1 to 70.26.255.25470.26.255.25532,766
5570.27.0.0/1770.27.0.1 to 70.27.127.25470.27.127.25532,766
5670.27.128.0/1770.27.128.1 to 70.27.255.25470.27.255.25532,766
5770.28.0.0/1770.28.0.1 to 70.28.127.25470.28.127.25532,766
5870.28.128.0/1770.28.128.1 to 70.28.255.25470.28.255.25532,766
5970.29.0.0/1770.29.0.1 to 70.29.127.25470.29.127.25532,766
6070.29.128.0/1770.29.128.1 to 70.29.255.25470.29.255.25532,766
6170.30.0.0/1770.30.0.1 to 70.30.127.25470.30.127.25532,766
6270.30.128.0/1770.30.128.1 to 70.30.255.25470.30.255.25532,766
6370.31.0.0/1770.31.0.1 to 70.31.127.25470.31.127.25532,766
6470.31.128.0/1770.31.128.1 to 70.31.255.25470.31.255.25532,766
6570.32.0.0/1770.32.0.1 to 70.32.127.25470.32.127.25532,766
6670.32.128.0/1770.32.128.1 to 70.32.255.25470.32.255.25532,766
6770.33.0.0/1770.33.0.1 to 70.33.127.25470.33.127.25532,766
6870.33.128.0/1770.33.128.1 to 70.33.255.25470.33.255.25532,766
6970.34.0.0/1770.34.0.1 to 70.34.127.25470.34.127.25532,766
7070.34.128.0/1770.34.128.1 to 70.34.255.25470.34.255.25532,766
7170.35.0.0/1770.35.0.1 to 70.35.127.25470.35.127.25532,766
7270.35.128.0/1770.35.128.1 to 70.35.255.25470.35.255.25532,766
7370.36.0.0/1770.36.0.1 to 70.36.127.25470.36.127.25532,766
7470.36.128.0/1770.36.128.1 to 70.36.255.25470.36.255.25532,766
7570.37.0.0/1770.37.0.1 to 70.37.127.25470.37.127.25532,766
7670.37.128.0/1770.37.128.1 to 70.37.255.25470.37.255.25532,766
7770.38.0.0/1770.38.0.1 to 70.38.127.25470.38.127.25532,766
7870.38.128.0/1770.38.128.1 to 70.38.255.25470.38.255.25532,766
7970.39.0.0/1770.39.0.1 to 70.39.127.25470.39.127.25532,766
8070.39.128.0/1770.39.128.1 to 70.39.255.25470.39.255.25532,766
8170.40.0.0/1770.40.0.1 to 70.40.127.25470.40.127.25532,766
8270.40.128.0/1770.40.128.1 to 70.40.255.25470.40.255.25532,766
8370.41.0.0/1770.41.0.1 to 70.41.127.25470.41.127.25532,766
8470.41.128.0/1770.41.128.1 to 70.41.255.25470.41.255.25532,766
8570.42.0.0/1770.42.0.1 to 70.42.127.25470.42.127.25532,766
8670.42.128.0/1770.42.128.1 to 70.42.255.25470.42.255.25532,766
8770.43.0.0/1770.43.0.1 to 70.43.127.25470.43.127.25532,766
8870.43.128.0/1770.43.128.1 to 70.43.255.25470.43.255.25532,766
8970.44.0.0/1770.44.0.1 to 70.44.127.25470.44.127.25532,766
9070.44.128.0/1770.44.128.1 to 70.44.255.25470.44.255.25532,766
9170.45.0.0/1770.45.0.1 to 70.45.127.25470.45.127.25532,766
9270.45.128.0/1770.45.128.1 to 70.45.255.25470.45.255.25532,766
9370.46.0.0/1770.46.0.1 to 70.46.127.25470.46.127.25532,766
9470.46.128.0/1770.46.128.1 to 70.46.255.25470.46.255.25532,766
9570.47.0.0/1770.47.0.1 to 70.47.127.25470.47.127.25532,766
9670.47.128.0/1770.47.128.1 to 70.47.255.25470.47.255.25532,766
9770.48.0.0/1770.48.0.1 to 70.48.127.25470.48.127.25532,766
9870.48.128.0/1770.48.128.1 to 70.48.255.25470.48.255.25532,766
9970.49.0.0/1770.49.0.1 to 70.49.127.25470.49.127.25532,766
10070.49.128.0/1770.49.128.1 to 70.49.255.25470.49.255.25532,766
10170.50.0.0/1770.50.0.1 to 70.50.127.25470.50.127.25532,766
10270.50.128.0/1770.50.128.1 to 70.50.255.25470.50.255.25532,766
10370.51.0.0/1770.51.0.1 to 70.51.127.25470.51.127.25532,766
10470.51.128.0/1770.51.128.1 to 70.51.255.25470.51.255.25532,766
10570.52.0.0/1770.52.0.1 to 70.52.127.25470.52.127.25532,766
10670.52.128.0/1770.52.128.1 to 70.52.255.25470.52.255.25532,766
10770.53.0.0/1770.53.0.1 to 70.53.127.25470.53.127.25532,766
10870.53.128.0/1770.53.128.1 to 70.53.255.25470.53.255.25532,766
10970.54.0.0/1770.54.0.1 to 70.54.127.25470.54.127.25532,766
11070.54.128.0/1770.54.128.1 to 70.54.255.25470.54.255.25532,766
11170.55.0.0/1770.55.0.1 to 70.55.127.25470.55.127.25532,766
11270.55.128.0/1770.55.128.1 to 70.55.255.25470.55.255.25532,766
11370.56.0.0/1770.56.0.1 to 70.56.127.25470.56.127.25532,766
11470.56.128.0/1770.56.128.1 to 70.56.255.25470.56.255.25532,766
11570.57.0.0/1770.57.0.1 to 70.57.127.25470.57.127.25532,766
11670.57.128.0/1770.57.128.1 to 70.57.255.25470.57.255.25532,766
11770.58.0.0/1770.58.0.1 to 70.58.127.25470.58.127.25532,766
11870.58.128.0/1770.58.128.1 to 70.58.255.25470.58.255.25532,766
11970.59.0.0/1770.59.0.1 to 70.59.127.25470.59.127.25532,766
12070.59.128.0/1770.59.128.1 to 70.59.255.25470.59.255.25532,766
12170.60.0.0/1770.60.0.1 to 70.60.127.25470.60.127.25532,766
12270.60.128.0/1770.60.128.1 to 70.60.255.25470.60.255.25532,766
12370.61.0.0/1770.61.0.1 to 70.61.127.25470.61.127.25532,766
12470.61.128.0/1770.61.128.1 to 70.61.255.25470.61.255.25532,766
12570.62.0.0/1770.62.0.1 to 70.62.127.25470.62.127.25532,766
12670.62.128.0/1770.62.128.1 to 70.62.255.25470.62.255.25532,766
12770.63.0.0/1770.63.0.1 to 70.63.127.25470.63.127.25532,766
12870.63.128.0/1770.63.128.1 to 70.63.255.25470.63.255.25532,766
12970.64.0.0/1770.64.0.1 to 70.64.127.25470.64.127.25532,766
13070.64.128.0/1770.64.128.1 to 70.64.255.25470.64.255.25532,766
13170.65.0.0/1770.65.0.1 to 70.65.127.25470.65.127.25532,766
13270.65.128.0/1770.65.128.1 to 70.65.255.25470.65.255.25532,766
13370.66.0.0/1770.66.0.1 to 70.66.127.25470.66.127.25532,766
13470.66.128.0/1770.66.128.1 to 70.66.255.25470.66.255.25532,766
13570.67.0.0/1770.67.0.1 to 70.67.127.25470.67.127.25532,766
13670.67.128.0/1770.67.128.1 to 70.67.255.25470.67.255.25532,766
13770.68.0.0/1770.68.0.1 to 70.68.127.25470.68.127.25532,766
13870.68.128.0/1770.68.128.1 to 70.68.255.25470.68.255.25532,766
13970.69.0.0/1770.69.0.1 to 70.69.127.25470.69.127.25532,766
14070.69.128.0/1770.69.128.1 to 70.69.255.25470.69.255.25532,766
14170.70.0.0/1770.70.0.1 to 70.70.127.25470.70.127.25532,766
14270.70.128.0/1770.70.128.1 to 70.70.255.25470.70.255.25532,766
14370.71.0.0/1770.71.0.1 to 70.71.127.25470.71.127.25532,766
14470.71.128.0/1770.71.128.1 to 70.71.255.25470.71.255.25532,766
14570.72.0.0/1770.72.0.1 to 70.72.127.25470.72.127.25532,766
14670.72.128.0/1770.72.128.1 to 70.72.255.25470.72.255.25532,766
14770.73.0.0/1770.73.0.1 to 70.73.127.25470.73.127.25532,766
14870.73.128.0/1770.73.128.1 to 70.73.255.25470.73.255.25532,766
14970.74.0.0/1770.74.0.1 to 70.74.127.25470.74.127.25532,766
15070.74.128.0/1770.74.128.1 to 70.74.255.25470.74.255.25532,766
15170.75.0.0/1770.75.0.1 to 70.75.127.25470.75.127.25532,766
15270.75.128.0/1770.75.128.1 to 70.75.255.25470.75.255.25532,766
15370.76.0.0/1770.76.0.1 to 70.76.127.25470.76.127.25532,766
15470.76.128.0/1770.76.128.1 to 70.76.255.25470.76.255.25532,766
15570.77.0.0/1770.77.0.1 to 70.77.127.25470.77.127.25532,766
15670.77.128.0/1770.77.128.1 to 70.77.255.25470.77.255.25532,766
15770.78.0.0/1770.78.0.1 to 70.78.127.25470.78.127.25532,766
15870.78.128.0/1770.78.128.1 to 70.78.255.25470.78.255.25532,766
15970.79.0.0/1770.79.0.1 to 70.79.127.25470.79.127.25532,766
16070.79.128.0/1770.79.128.1 to 70.79.255.25470.79.255.25532,766
16170.80.0.0/1770.80.0.1 to 70.80.127.25470.80.127.25532,766
16270.80.128.0/1770.80.128.1 to 70.80.255.25470.80.255.25532,766
16370.81.0.0/1770.81.0.1 to 70.81.127.25470.81.127.25532,766
16470.81.128.0/1770.81.128.1 to 70.81.255.25470.81.255.25532,766
16570.82.0.0/1770.82.0.1 to 70.82.127.25470.82.127.25532,766
16670.82.128.0/1770.82.128.1 to 70.82.255.25470.82.255.25532,766
16770.83.0.0/1770.83.0.1 to 70.83.127.25470.83.127.25532,766
16870.83.128.0/1770.83.128.1 to 70.83.255.25470.83.255.25532,766
16970.84.0.0/1770.84.0.1 to 70.84.127.25470.84.127.25532,766
17070.84.128.0/1770.84.128.1 to 70.84.255.25470.84.255.25532,766
17170.85.0.0/1770.85.0.1 to 70.85.127.25470.85.127.25532,766
17270.85.128.0/1770.85.128.1 to 70.85.255.25470.85.255.25532,766
17370.86.0.0/1770.86.0.1 to 70.86.127.25470.86.127.25532,766
17470.86.128.0/1770.86.128.1 to 70.86.255.25470.86.255.25532,766
17570.87.0.0/1770.87.0.1 to 70.87.127.25470.87.127.25532,766
17670.87.128.0/1770.87.128.1 to 70.87.255.25470.87.255.25532,766
17770.88.0.0/1770.88.0.1 to 70.88.127.25470.88.127.25532,766
17870.88.128.0/1770.88.128.1 to 70.88.255.25470.88.255.25532,766
17970.89.0.0/1770.89.0.1 to 70.89.127.25470.89.127.25532,766
18070.89.128.0/1770.89.128.1 to 70.89.255.25470.89.255.25532,766
18170.90.0.0/1770.90.0.1 to 70.90.127.25470.90.127.25532,766
18270.90.128.0/1770.90.128.1 to 70.90.255.25470.90.255.25532,766
18370.91.0.0/1770.91.0.1 to 70.91.127.25470.91.127.25532,766
18470.91.128.0/1770.91.128.1 to 70.91.255.25470.91.255.25532,766
18570.92.0.0/1770.92.0.1 to 70.92.127.25470.92.127.25532,766
18670.92.128.0/1770.92.128.1 to 70.92.255.25470.92.255.25532,766
18770.93.0.0/1770.93.0.1 to 70.93.127.25470.93.127.25532,766
18870.93.128.0/1770.93.128.1 to 70.93.255.25470.93.255.25532,766
18970.94.0.0/1770.94.0.1 to 70.94.127.25470.94.127.25532,766
19070.94.128.0/1770.94.128.1 to 70.94.255.25470.94.255.25532,766
19170.95.0.0/1770.95.0.1 to 70.95.127.25470.95.127.25532,766
19270.95.128.0/1770.95.128.1 to 70.95.255.25470.95.255.25532,766
19370.96.0.0/1770.96.0.1 to 70.96.127.25470.96.127.25532,766
19470.96.128.0/1770.96.128.1 to 70.96.255.25470.96.255.25532,766
19570.97.0.0/1770.97.0.1 to 70.97.127.25470.97.127.25532,766
19670.97.128.0/1770.97.128.1 to 70.97.255.25470.97.255.25532,766
19770.98.0.0/1770.98.0.1 to 70.98.127.25470.98.127.25532,766
19870.98.128.0/1770.98.128.1 to 70.98.255.25470.98.255.25532,766
19970.99.0.0/1770.99.0.1 to 70.99.127.25470.99.127.25532,766
20070.99.128.0/1770.99.128.1 to 70.99.255.25470.99.255.25532,766
20170.100.0.0/1770.100.0.1 to 70.100.127.25470.100.127.25532,766
20270.100.128.0/1770.100.128.1 to 70.100.255.25470.100.255.25532,766
20370.101.0.0/1770.101.0.1 to 70.101.127.25470.101.127.25532,766
20470.101.128.0/1770.101.128.1 to 70.101.255.25470.101.255.25532,766
20570.102.0.0/1770.102.0.1 to 70.102.127.25470.102.127.25532,766
20670.102.128.0/1770.102.128.1 to 70.102.255.25470.102.255.25532,766
20770.103.0.0/1770.103.0.1 to 70.103.127.25470.103.127.25532,766
20870.103.128.0/1770.103.128.1 to 70.103.255.25470.103.255.25532,766
20970.104.0.0/1770.104.0.1 to 70.104.127.25470.104.127.25532,766
21070.104.128.0/1770.104.128.1 to 70.104.255.25470.104.255.25532,766
21170.105.0.0/1770.105.0.1 to 70.105.127.25470.105.127.25532,766
21270.105.128.0/1770.105.128.1 to 70.105.255.25470.105.255.25532,766
21370.106.0.0/1770.106.0.1 to 70.106.127.25470.106.127.25532,766
21470.106.128.0/1770.106.128.1 to 70.106.255.25470.106.255.25532,766
21570.107.0.0/1770.107.0.1 to 70.107.127.25470.107.127.25532,766
21670.107.128.0/1770.107.128.1 to 70.107.255.25470.107.255.25532,766
21770.108.0.0/1770.108.0.1 to 70.108.127.25470.108.127.25532,766
21870.108.128.0/1770.108.128.1 to 70.108.255.25470.108.255.25532,766
21970.109.0.0/1770.109.0.1 to 70.109.127.25470.109.127.25532,766
22070.109.128.0/1770.109.128.1 to 70.109.255.25470.109.255.25532,766
22170.110.0.0/1770.110.0.1 to 70.110.127.25470.110.127.25532,766
22270.110.128.0/1770.110.128.1 to 70.110.255.25470.110.255.25532,766
22370.111.0.0/1770.111.0.1 to 70.111.127.25470.111.127.25532,766
22470.111.128.0/1770.111.128.1 to 70.111.255.25470.111.255.25532,766
22570.112.0.0/1770.112.0.1 to 70.112.127.25470.112.127.25532,766
22670.112.128.0/1770.112.128.1 to 70.112.255.25470.112.255.25532,766
22770.113.0.0/1770.113.0.1 to 70.113.127.25470.113.127.25532,766
22870.113.128.0/1770.113.128.1 to 70.113.255.25470.113.255.25532,766
22970.114.0.0/1770.114.0.1 to 70.114.127.25470.114.127.25532,766
23070.114.128.0/1770.114.128.1 to 70.114.255.25470.114.255.25532,766
23170.115.0.0/1770.115.0.1 to 70.115.127.25470.115.127.25532,766
23270.115.128.0/1770.115.128.1 to 70.115.255.25470.115.255.25532,766
23370.116.0.0/1770.116.0.1 to 70.116.127.25470.116.127.25532,766
23470.116.128.0/1770.116.128.1 to 70.116.255.25470.116.255.25532,766
23570.117.0.0/1770.117.0.1 to 70.117.127.25470.117.127.25532,766
23670.117.128.0/1770.117.128.1 to 70.117.255.25470.117.255.25532,766
23770.118.0.0/1770.118.0.1 to 70.118.127.25470.118.127.25532,766
23870.118.128.0/1770.118.128.1 to 70.118.255.25470.118.255.25532,766
23970.119.0.0/1770.119.0.1 to 70.119.127.25470.119.127.25532,766
24070.119.128.0/1770.119.128.1 to 70.119.255.25470.119.255.25532,766
24170.120.0.0/1770.120.0.1 to 70.120.127.25470.120.127.25532,766
24270.120.128.0/1770.120.128.1 to 70.120.255.25470.120.255.25532,766
24370.121.0.0/1770.121.0.1 to 70.121.127.25470.121.127.25532,766
24470.121.128.0/1770.121.128.1 to 70.121.255.25470.121.255.25532,766
24570.122.0.0/1770.122.0.1 to 70.122.127.25470.122.127.25532,766
24670.122.128.0/1770.122.128.1 to 70.122.255.25470.122.255.25532,766
24770.123.0.0/1770.123.0.1 to 70.123.127.25470.123.127.25532,766
24870.123.128.0/1770.123.128.1 to 70.123.255.25470.123.255.25532,766
24970.124.0.0/1770.124.0.1 to 70.124.127.25470.124.127.25532,766
25070.124.128.0/1770.124.128.1 to 70.124.255.25470.124.255.25532,766
25170.125.0.0/1770.125.0.1 to 70.125.127.25470.125.127.25532,766
25270.125.128.0/1770.125.128.1 to 70.125.255.25470.125.255.25532,766
25370.126.0.0/1770.126.0.1 to 70.126.127.25470.126.127.25532,766
25470.126.128.0/1770.126.128.1 to 70.126.255.25470.126.255.25532,766
25570.127.0.0/1770.127.0.1 to 70.127.127.25470.127.127.25532,766
25670.127.128.0/1770.127.128.1 to 70.127.255.25470.127.255.25532,766

IPv4 CIDR reference (/0 to /32)

IPv4 prefix lengths
PrefixSubnet maskWildcardAddressesUsable hostsSizeTypical use
/00.0.0.0255.255.255.2554,294,967,2964,294,967,29416,777,216 × /24
/1128.0.0.0127.255.255.2552,147,483,6482,147,483,6468,388,608 × /24
/2192.0.0.063.255.255.2551,073,741,8241,073,741,8224,194,304 × /24
/3224.0.0.031.255.255.255536,870,912536,870,9102,097,152 × /24
/4240.0.0.015.255.255.255268,435,456268,435,4541,048,576 × /24
/5248.0.0.07.255.255.255134,217,728134,217,726524,288 × /24
/6252.0.0.03.255.255.25567,108,86467,108,862262,144 × /24
/7254.0.0.01.255.255.25533,554,43233,554,430131,072 × /24
/8255.0.0.00.255.255.25516,777,21616,777,21465,536 × /24Old class A; 10.0.0.0/8
/9255.128.0.00.127.255.2558,388,6088,388,60632,768 × /24
/10255.192.0.00.63.255.2554,194,3044,194,30216,384 × /24
/11255.224.0.00.31.255.2552,097,1522,097,1508,192 × /24
/12255.240.0.00.15.255.2551,048,5761,048,5744,096 × /24172.16.0.0/12
/13255.248.0.00.7.255.255524,288524,2862,048 × /24
/14255.252.0.00.3.255.255262,144262,1421,024 × /24
/15255.254.0.00.1.255.255131,072131,070512 × /24
/16255.255.0.00.0.255.25565,53665,534256 × /24Old class B; 192.168.0.0/16
/17255.255.128.00.0.127.25532,76832,766128 × /24
/18255.255.192.00.0.63.25516,38416,38264 × /24
/19255.255.224.00.0.31.2558,1928,19032 × /24
/20255.255.240.00.0.15.2554,0964,09416 × /24
/21255.255.248.00.0.7.2552,0482,0468 × /24
/22255.255.252.00.0.3.2551,0241,0224 × /24Large office or guest Wi-Fi (1,022 hosts)
/23255.255.254.00.0.1.2555125102 × /24Larger office LAN (510 hosts)
/24255.255.255.00.0.0.2552562541 × /24Typical office LAN (old class C)
/25255.255.255.1280.0.0.1271281261/2 of a /24Smaller LAN or VLAN
/26255.255.255.1920.0.0.6364621/4 of a /24Smaller LAN or VLAN
/27255.255.255.2240.0.0.3132301/8 of a /24Small VLAN, phones, cameras
/28255.255.255.2400.0.0.1516141/16 of a /24Small VLAN, phones, cameras
/29255.255.255.2480.0.0.7861/32 of a /24Small fixed public block (5 usable)
/30255.255.255.2520.0.0.3421/64 of a /24Point-to-point (old style)
/31255.255.255.2540.0.0.1221/128 of a /24Point-to-point link (RFC 3021)
/32255.255.255.2550.0.0.0111/256 of a /24One host

IPv6 prefix reference

IPv6 prefix lengths
PrefixAddresses/64 LANs/48 sitesNibbleTypical use
/342,535,295,865,117,307,932,921,825,928,971,026,432 (2^125)2,305,843,009,213,693,95235,184,372,088,832NoAll global unicast (2000::/3)
/165,192,296,858,534,827,628,530,496,329,220,096 (2^112)281,474,976,710,6564,294,967,296Yes
/20324,518,553,658,426,726,783,156,020,576,256 (2^108)17,592,186,044,416268,435,456YesLarge provider allocation (RIPE minimum for some)
/29633,825,300,114,114,700,748,351,602,688 (2^99)34,359,738,368524,288NoRIPE allocation to a provider (often)
/3279,228,162,514,264,337,593,543,950,336 (2^96)4,294,967,29665,536YesProvider allocation (RIPE default)
/364,951,760,157,141,521,099,596,496,896 (2^92)268,435,4564,096Yes
/40309,485,009,821,345,068,724,781,056 (2^88)16,777,216256Yes
/4419,342,813,113,834,066,795,298,816 (2^84)1,048,57616Yes
/481,208,925,819,614,629,174,706,176 (2^80)65,5361YesOne site or organisation (RIPE PI / assignment)
/5275,557,863,725,914,323,419,136 (2^76)4,096Yes
/564,722,366,482,869,645,213,696 (2^72)256YesSmall site or home (common provider assignment)
/60295,147,905,179,352,825,856 (2^68)16YesSome home broadband (16 LANs)
/6418,446,744,073,709,551,616 (2^64)1YesOne LAN or VLAN (needed for SLAAC)
/7272,057,594,037,927,936 (2^56)1/256 of a /64Yes
/80281,474,976,710,656 (2^48)1/65,536 of a /64Yes
/964,294,967,2961/4,294,967,296 of a /64YesEmbeds an IPv4 address (NAT64)
/11265,5361/281,474,976,710,656 of a /64Yes
/1202561/72,057,594,037,927,936 of a /64Yes
/124161/1,152,921,504,606,846,976 of a /64Yes
/12641/4,611,686,018,427,387,904 of a /64No
/12721/9,223,372,036,854,775,808 of a /64NoPoint-to-point link (RFC 6164)
/12811/18,446,744,073,709,551,616 of a /64YesOne host or loopback

Private and special ranges

IPv4

Special-purpose ranges
RangeNameWhat it is
255.255.255.255/32Limited broadcastEvery host on the local network
0.0.0.0/8This networkNot routed; 0.0.0.0 means "any address" in settings
10.0.0.0/8Private (RFC 1918)Office and home networks; not routed on the internet
100.64.0.0/10Shared address space (CGNAT)Used by providers behind carrier-grade NAT (RFC 6598)
127.0.0.0/8LoopbackThis computer
169.254.0.0/16Link-local (APIPA)Self-assigned when no DHCP server answers
172.16.0.0/12Private (RFC 1918)Office and home networks; not routed on the internet
192.0.0.0/24IETF protocol assignmentsSpecial uses such as DS-Lite
192.0.2.0/24Documentation (TEST-NET-1)For examples; never used on a network
192.88.99.0/246to4 relay (deprecated)Formerly anycast for 6to4
192.168.0.0/16Private (RFC 1918)Office and home networks; not routed on the internet
198.18.0.0/15BenchmarkingNetwork equipment testing (RFC 2544)
198.51.100.0/24Documentation (TEST-NET-2)For examples; never used on a network
203.0.113.0/24Documentation (TEST-NET-3)For examples; never used on a network
224.0.0.0/4MulticastOne-to-many traffic, such as IPTV and routing protocols
240.0.0.0/4ReservedFuture use; not usable on most systems

IPv6

Special-purpose ranges
RangeNameWhat it is
::/128UnspecifiedNo address; :: means "any address" in settings
::1/128LoopbackThis computer
::ffff:0:0/96IPv4-mappedAn IPv4 address written as IPv6
64:ff9b::/96NAT64IPv4 addresses reached through a NAT64 gateway
100::/64Discard onlyTraffic sent here is dropped (RFC 6666)
2001:db8::/32DocumentationFor examples; never used on a network
2001::/32TeredoIPv6 tunnelled over IPv4 UDP
2002::/166to4IPv6 tunnelled over IPv4 (largely retired)
3fff::/20DocumentationFor examples (RFC 9637)
fc00::/7Unique local (ULA)Private IPv6, like RFC 1918; usually fd00::/8
fe80::/10Link-localEvery IPv6 interface has one; not routed
ff00::/8MulticastOne-to-many traffic; replaces broadcast
2000::/3Global unicastPublic internet addresses

About this tool

A network is written as an address and a prefix length, such as 192.168.1.0/24: the first 24 bits name the network and the rest number the devices on it. The calculator works out where the network starts and ends, how many devices it holds, its subnet and wildcard masks, and the reverse DNS zone to ask your provider for.

It also splits a network into equal smaller ones (one per VLAN or site), turns a range of addresses into the fewest CIDR blocks for a firewall rule, and lists every IPv4 prefix length and the common IPv6 ones in reference tables.

Common questions

Why are two addresses lost in every IPv4 subnet?

The first address names the network and the last is the broadcast address, so a /24 has 256 addresses but 254 for devices. A /31 (a link between two routers) and a /32 (one host) are the exceptions.

What size of IPv6 network should a LAN use?

Always /64. Devices pick their own address within it (SLAAC), which needs the full 64 bits. A site usually gets a /48 or /56 from its provider, which holds 65,536 or 256 LANs.

What is a wildcard mask?

The subnet mask turned inside out: 255.255.255.0 becomes 0.0.0.255. Cisco access lists and OSPF use it to say which bits must match.

Which ranges can I use inside an office?

IPv4: 10.0.0.0/8, 172.16.0.0/12 and 192.168.0.0/16. IPv6: unique local addresses from fd00::/8, though most networks use the public prefix from their provider.