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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.

Network50.0.0.0/7
Usable hosts33,554,430
Subnet mask254.0.0.0
Addresses33,554,432
Network address
50.0.0.0
Broadcast address
51.255.255.255
First usable
50.0.0.1
Last usable
51.255.255.254
Usable hosts
33,554,430 (33,554,432 less the network and broadcast addresses)
Subnet mask
254.0.0.0
Wildcard mask
1.255.255.255 (Cisco ACLs, OSPF)
Prefix length
/7
Type
Public public
Old class
A (default /8)
As numbers
Hex 32000000 · Integer 838860800 to 872415231
Reverse DNS zones
50.in-addr.arpa
51.in-addr.arpa
/7 is not on a 8-bit boundary, so it takes 2 /8 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address00110010.00000000.00000000.0000000050.0.0.0
Subnet mask11111110.00000000.00000000.00000000254.0.0.0
Network00110010.00000000.00000000.0000000050.0.0.0
Broadcast00110011.11111111.11111111.1111111151.255.255.255
Split into smaller subnets/17
/8 (2)/9 (4)/10 (8)/11 (16)/12 (32)/13 (64)/14 (128)/15 (256)/16 (512)/17 (1,024)/18 (2,048)/19 (4,096)

50.0.0.0/7 makes 1,024 subnets of /17; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
150.0.0.0/1750.0.0.1 to 50.0.127.25450.0.127.25532,766
250.0.128.0/1750.0.128.1 to 50.0.255.25450.0.255.25532,766
350.1.0.0/1750.1.0.1 to 50.1.127.25450.1.127.25532,766
450.1.128.0/1750.1.128.1 to 50.1.255.25450.1.255.25532,766
550.2.0.0/1750.2.0.1 to 50.2.127.25450.2.127.25532,766
650.2.128.0/1750.2.128.1 to 50.2.255.25450.2.255.25532,766
750.3.0.0/1750.3.0.1 to 50.3.127.25450.3.127.25532,766
850.3.128.0/1750.3.128.1 to 50.3.255.25450.3.255.25532,766
950.4.0.0/1750.4.0.1 to 50.4.127.25450.4.127.25532,766
1050.4.128.0/1750.4.128.1 to 50.4.255.25450.4.255.25532,766
1150.5.0.0/1750.5.0.1 to 50.5.127.25450.5.127.25532,766
1250.5.128.0/1750.5.128.1 to 50.5.255.25450.5.255.25532,766
1350.6.0.0/1750.6.0.1 to 50.6.127.25450.6.127.25532,766
1450.6.128.0/1750.6.128.1 to 50.6.255.25450.6.255.25532,766
1550.7.0.0/1750.7.0.1 to 50.7.127.25450.7.127.25532,766
1650.7.128.0/1750.7.128.1 to 50.7.255.25450.7.255.25532,766
1750.8.0.0/1750.8.0.1 to 50.8.127.25450.8.127.25532,766
1850.8.128.0/1750.8.128.1 to 50.8.255.25450.8.255.25532,766
1950.9.0.0/1750.9.0.1 to 50.9.127.25450.9.127.25532,766
2050.9.128.0/1750.9.128.1 to 50.9.255.25450.9.255.25532,766
2150.10.0.0/1750.10.0.1 to 50.10.127.25450.10.127.25532,766
2250.10.128.0/1750.10.128.1 to 50.10.255.25450.10.255.25532,766
2350.11.0.0/1750.11.0.1 to 50.11.127.25450.11.127.25532,766
2450.11.128.0/1750.11.128.1 to 50.11.255.25450.11.255.25532,766
2550.12.0.0/1750.12.0.1 to 50.12.127.25450.12.127.25532,766
2650.12.128.0/1750.12.128.1 to 50.12.255.25450.12.255.25532,766
2750.13.0.0/1750.13.0.1 to 50.13.127.25450.13.127.25532,766
2850.13.128.0/1750.13.128.1 to 50.13.255.25450.13.255.25532,766
2950.14.0.0/1750.14.0.1 to 50.14.127.25450.14.127.25532,766
3050.14.128.0/1750.14.128.1 to 50.14.255.25450.14.255.25532,766
3150.15.0.0/1750.15.0.1 to 50.15.127.25450.15.127.25532,766
3250.15.128.0/1750.15.128.1 to 50.15.255.25450.15.255.25532,766
3350.16.0.0/1750.16.0.1 to 50.16.127.25450.16.127.25532,766
3450.16.128.0/1750.16.128.1 to 50.16.255.25450.16.255.25532,766
3550.17.0.0/1750.17.0.1 to 50.17.127.25450.17.127.25532,766
3650.17.128.0/1750.17.128.1 to 50.17.255.25450.17.255.25532,766
3750.18.0.0/1750.18.0.1 to 50.18.127.25450.18.127.25532,766
3850.18.128.0/1750.18.128.1 to 50.18.255.25450.18.255.25532,766
3950.19.0.0/1750.19.0.1 to 50.19.127.25450.19.127.25532,766
4050.19.128.0/1750.19.128.1 to 50.19.255.25450.19.255.25532,766
4150.20.0.0/1750.20.0.1 to 50.20.127.25450.20.127.25532,766
4250.20.128.0/1750.20.128.1 to 50.20.255.25450.20.255.25532,766
4350.21.0.0/1750.21.0.1 to 50.21.127.25450.21.127.25532,766
4450.21.128.0/1750.21.128.1 to 50.21.255.25450.21.255.25532,766
4550.22.0.0/1750.22.0.1 to 50.22.127.25450.22.127.25532,766
4650.22.128.0/1750.22.128.1 to 50.22.255.25450.22.255.25532,766
4750.23.0.0/1750.23.0.1 to 50.23.127.25450.23.127.25532,766
4850.23.128.0/1750.23.128.1 to 50.23.255.25450.23.255.25532,766
4950.24.0.0/1750.24.0.1 to 50.24.127.25450.24.127.25532,766
5050.24.128.0/1750.24.128.1 to 50.24.255.25450.24.255.25532,766
5150.25.0.0/1750.25.0.1 to 50.25.127.25450.25.127.25532,766
5250.25.128.0/1750.25.128.1 to 50.25.255.25450.25.255.25532,766
5350.26.0.0/1750.26.0.1 to 50.26.127.25450.26.127.25532,766
5450.26.128.0/1750.26.128.1 to 50.26.255.25450.26.255.25532,766
5550.27.0.0/1750.27.0.1 to 50.27.127.25450.27.127.25532,766
5650.27.128.0/1750.27.128.1 to 50.27.255.25450.27.255.25532,766
5750.28.0.0/1750.28.0.1 to 50.28.127.25450.28.127.25532,766
5850.28.128.0/1750.28.128.1 to 50.28.255.25450.28.255.25532,766
5950.29.0.0/1750.29.0.1 to 50.29.127.25450.29.127.25532,766
6050.29.128.0/1750.29.128.1 to 50.29.255.25450.29.255.25532,766
6150.30.0.0/1750.30.0.1 to 50.30.127.25450.30.127.25532,766
6250.30.128.0/1750.30.128.1 to 50.30.255.25450.30.255.25532,766
6350.31.0.0/1750.31.0.1 to 50.31.127.25450.31.127.25532,766
6450.31.128.0/1750.31.128.1 to 50.31.255.25450.31.255.25532,766
6550.32.0.0/1750.32.0.1 to 50.32.127.25450.32.127.25532,766
6650.32.128.0/1750.32.128.1 to 50.32.255.25450.32.255.25532,766
6750.33.0.0/1750.33.0.1 to 50.33.127.25450.33.127.25532,766
6850.33.128.0/1750.33.128.1 to 50.33.255.25450.33.255.25532,766
6950.34.0.0/1750.34.0.1 to 50.34.127.25450.34.127.25532,766
7050.34.128.0/1750.34.128.1 to 50.34.255.25450.34.255.25532,766
7150.35.0.0/1750.35.0.1 to 50.35.127.25450.35.127.25532,766
7250.35.128.0/1750.35.128.1 to 50.35.255.25450.35.255.25532,766
7350.36.0.0/1750.36.0.1 to 50.36.127.25450.36.127.25532,766
7450.36.128.0/1750.36.128.1 to 50.36.255.25450.36.255.25532,766
7550.37.0.0/1750.37.0.1 to 50.37.127.25450.37.127.25532,766
7650.37.128.0/1750.37.128.1 to 50.37.255.25450.37.255.25532,766
7750.38.0.0/1750.38.0.1 to 50.38.127.25450.38.127.25532,766
7850.38.128.0/1750.38.128.1 to 50.38.255.25450.38.255.25532,766
7950.39.0.0/1750.39.0.1 to 50.39.127.25450.39.127.25532,766
8050.39.128.0/1750.39.128.1 to 50.39.255.25450.39.255.25532,766
8150.40.0.0/1750.40.0.1 to 50.40.127.25450.40.127.25532,766
8250.40.128.0/1750.40.128.1 to 50.40.255.25450.40.255.25532,766
8350.41.0.0/1750.41.0.1 to 50.41.127.25450.41.127.25532,766
8450.41.128.0/1750.41.128.1 to 50.41.255.25450.41.255.25532,766
8550.42.0.0/1750.42.0.1 to 50.42.127.25450.42.127.25532,766
8650.42.128.0/1750.42.128.1 to 50.42.255.25450.42.255.25532,766
8750.43.0.0/1750.43.0.1 to 50.43.127.25450.43.127.25532,766
8850.43.128.0/1750.43.128.1 to 50.43.255.25450.43.255.25532,766
8950.44.0.0/1750.44.0.1 to 50.44.127.25450.44.127.25532,766
9050.44.128.0/1750.44.128.1 to 50.44.255.25450.44.255.25532,766
9150.45.0.0/1750.45.0.1 to 50.45.127.25450.45.127.25532,766
9250.45.128.0/1750.45.128.1 to 50.45.255.25450.45.255.25532,766
9350.46.0.0/1750.46.0.1 to 50.46.127.25450.46.127.25532,766
9450.46.128.0/1750.46.128.1 to 50.46.255.25450.46.255.25532,766
9550.47.0.0/1750.47.0.1 to 50.47.127.25450.47.127.25532,766
9650.47.128.0/1750.47.128.1 to 50.47.255.25450.47.255.25532,766
9750.48.0.0/1750.48.0.1 to 50.48.127.25450.48.127.25532,766
9850.48.128.0/1750.48.128.1 to 50.48.255.25450.48.255.25532,766
9950.49.0.0/1750.49.0.1 to 50.49.127.25450.49.127.25532,766
10050.49.128.0/1750.49.128.1 to 50.49.255.25450.49.255.25532,766
10150.50.0.0/1750.50.0.1 to 50.50.127.25450.50.127.25532,766
10250.50.128.0/1750.50.128.1 to 50.50.255.25450.50.255.25532,766
10350.51.0.0/1750.51.0.1 to 50.51.127.25450.51.127.25532,766
10450.51.128.0/1750.51.128.1 to 50.51.255.25450.51.255.25532,766
10550.52.0.0/1750.52.0.1 to 50.52.127.25450.52.127.25532,766
10650.52.128.0/1750.52.128.1 to 50.52.255.25450.52.255.25532,766
10750.53.0.0/1750.53.0.1 to 50.53.127.25450.53.127.25532,766
10850.53.128.0/1750.53.128.1 to 50.53.255.25450.53.255.25532,766
10950.54.0.0/1750.54.0.1 to 50.54.127.25450.54.127.25532,766
11050.54.128.0/1750.54.128.1 to 50.54.255.25450.54.255.25532,766
11150.55.0.0/1750.55.0.1 to 50.55.127.25450.55.127.25532,766
11250.55.128.0/1750.55.128.1 to 50.55.255.25450.55.255.25532,766
11350.56.0.0/1750.56.0.1 to 50.56.127.25450.56.127.25532,766
11450.56.128.0/1750.56.128.1 to 50.56.255.25450.56.255.25532,766
11550.57.0.0/1750.57.0.1 to 50.57.127.25450.57.127.25532,766
11650.57.128.0/1750.57.128.1 to 50.57.255.25450.57.255.25532,766
11750.58.0.0/1750.58.0.1 to 50.58.127.25450.58.127.25532,766
11850.58.128.0/1750.58.128.1 to 50.58.255.25450.58.255.25532,766
11950.59.0.0/1750.59.0.1 to 50.59.127.25450.59.127.25532,766
12050.59.128.0/1750.59.128.1 to 50.59.255.25450.59.255.25532,766
12150.60.0.0/1750.60.0.1 to 50.60.127.25450.60.127.25532,766
12250.60.128.0/1750.60.128.1 to 50.60.255.25450.60.255.25532,766
12350.61.0.0/1750.61.0.1 to 50.61.127.25450.61.127.25532,766
12450.61.128.0/1750.61.128.1 to 50.61.255.25450.61.255.25532,766
12550.62.0.0/1750.62.0.1 to 50.62.127.25450.62.127.25532,766
12650.62.128.0/1750.62.128.1 to 50.62.255.25450.62.255.25532,766
12750.63.0.0/1750.63.0.1 to 50.63.127.25450.63.127.25532,766
12850.63.128.0/1750.63.128.1 to 50.63.255.25450.63.255.25532,766
12950.64.0.0/1750.64.0.1 to 50.64.127.25450.64.127.25532,766
13050.64.128.0/1750.64.128.1 to 50.64.255.25450.64.255.25532,766
13150.65.0.0/1750.65.0.1 to 50.65.127.25450.65.127.25532,766
13250.65.128.0/1750.65.128.1 to 50.65.255.25450.65.255.25532,766
13350.66.0.0/1750.66.0.1 to 50.66.127.25450.66.127.25532,766
13450.66.128.0/1750.66.128.1 to 50.66.255.25450.66.255.25532,766
13550.67.0.0/1750.67.0.1 to 50.67.127.25450.67.127.25532,766
13650.67.128.0/1750.67.128.1 to 50.67.255.25450.67.255.25532,766
13750.68.0.0/1750.68.0.1 to 50.68.127.25450.68.127.25532,766
13850.68.128.0/1750.68.128.1 to 50.68.255.25450.68.255.25532,766
13950.69.0.0/1750.69.0.1 to 50.69.127.25450.69.127.25532,766
14050.69.128.0/1750.69.128.1 to 50.69.255.25450.69.255.25532,766
14150.70.0.0/1750.70.0.1 to 50.70.127.25450.70.127.25532,766
14250.70.128.0/1750.70.128.1 to 50.70.255.25450.70.255.25532,766
14350.71.0.0/1750.71.0.1 to 50.71.127.25450.71.127.25532,766
14450.71.128.0/1750.71.128.1 to 50.71.255.25450.71.255.25532,766
14550.72.0.0/1750.72.0.1 to 50.72.127.25450.72.127.25532,766
14650.72.128.0/1750.72.128.1 to 50.72.255.25450.72.255.25532,766
14750.73.0.0/1750.73.0.1 to 50.73.127.25450.73.127.25532,766
14850.73.128.0/1750.73.128.1 to 50.73.255.25450.73.255.25532,766
14950.74.0.0/1750.74.0.1 to 50.74.127.25450.74.127.25532,766
15050.74.128.0/1750.74.128.1 to 50.74.255.25450.74.255.25532,766
15150.75.0.0/1750.75.0.1 to 50.75.127.25450.75.127.25532,766
15250.75.128.0/1750.75.128.1 to 50.75.255.25450.75.255.25532,766
15350.76.0.0/1750.76.0.1 to 50.76.127.25450.76.127.25532,766
15450.76.128.0/1750.76.128.1 to 50.76.255.25450.76.255.25532,766
15550.77.0.0/1750.77.0.1 to 50.77.127.25450.77.127.25532,766
15650.77.128.0/1750.77.128.1 to 50.77.255.25450.77.255.25532,766
15750.78.0.0/1750.78.0.1 to 50.78.127.25450.78.127.25532,766
15850.78.128.0/1750.78.128.1 to 50.78.255.25450.78.255.25532,766
15950.79.0.0/1750.79.0.1 to 50.79.127.25450.79.127.25532,766
16050.79.128.0/1750.79.128.1 to 50.79.255.25450.79.255.25532,766
16150.80.0.0/1750.80.0.1 to 50.80.127.25450.80.127.25532,766
16250.80.128.0/1750.80.128.1 to 50.80.255.25450.80.255.25532,766
16350.81.0.0/1750.81.0.1 to 50.81.127.25450.81.127.25532,766
16450.81.128.0/1750.81.128.1 to 50.81.255.25450.81.255.25532,766
16550.82.0.0/1750.82.0.1 to 50.82.127.25450.82.127.25532,766
16650.82.128.0/1750.82.128.1 to 50.82.255.25450.82.255.25532,766
16750.83.0.0/1750.83.0.1 to 50.83.127.25450.83.127.25532,766
16850.83.128.0/1750.83.128.1 to 50.83.255.25450.83.255.25532,766
16950.84.0.0/1750.84.0.1 to 50.84.127.25450.84.127.25532,766
17050.84.128.0/1750.84.128.1 to 50.84.255.25450.84.255.25532,766
17150.85.0.0/1750.85.0.1 to 50.85.127.25450.85.127.25532,766
17250.85.128.0/1750.85.128.1 to 50.85.255.25450.85.255.25532,766
17350.86.0.0/1750.86.0.1 to 50.86.127.25450.86.127.25532,766
17450.86.128.0/1750.86.128.1 to 50.86.255.25450.86.255.25532,766
17550.87.0.0/1750.87.0.1 to 50.87.127.25450.87.127.25532,766
17650.87.128.0/1750.87.128.1 to 50.87.255.25450.87.255.25532,766
17750.88.0.0/1750.88.0.1 to 50.88.127.25450.88.127.25532,766
17850.88.128.0/1750.88.128.1 to 50.88.255.25450.88.255.25532,766
17950.89.0.0/1750.89.0.1 to 50.89.127.25450.89.127.25532,766
18050.89.128.0/1750.89.128.1 to 50.89.255.25450.89.255.25532,766
18150.90.0.0/1750.90.0.1 to 50.90.127.25450.90.127.25532,766
18250.90.128.0/1750.90.128.1 to 50.90.255.25450.90.255.25532,766
18350.91.0.0/1750.91.0.1 to 50.91.127.25450.91.127.25532,766
18450.91.128.0/1750.91.128.1 to 50.91.255.25450.91.255.25532,766
18550.92.0.0/1750.92.0.1 to 50.92.127.25450.92.127.25532,766
18650.92.128.0/1750.92.128.1 to 50.92.255.25450.92.255.25532,766
18750.93.0.0/1750.93.0.1 to 50.93.127.25450.93.127.25532,766
18850.93.128.0/1750.93.128.1 to 50.93.255.25450.93.255.25532,766
18950.94.0.0/1750.94.0.1 to 50.94.127.25450.94.127.25532,766
19050.94.128.0/1750.94.128.1 to 50.94.255.25450.94.255.25532,766
19150.95.0.0/1750.95.0.1 to 50.95.127.25450.95.127.25532,766
19250.95.128.0/1750.95.128.1 to 50.95.255.25450.95.255.25532,766
19350.96.0.0/1750.96.0.1 to 50.96.127.25450.96.127.25532,766
19450.96.128.0/1750.96.128.1 to 50.96.255.25450.96.255.25532,766
19550.97.0.0/1750.97.0.1 to 50.97.127.25450.97.127.25532,766
19650.97.128.0/1750.97.128.1 to 50.97.255.25450.97.255.25532,766
19750.98.0.0/1750.98.0.1 to 50.98.127.25450.98.127.25532,766
19850.98.128.0/1750.98.128.1 to 50.98.255.25450.98.255.25532,766
19950.99.0.0/1750.99.0.1 to 50.99.127.25450.99.127.25532,766
20050.99.128.0/1750.99.128.1 to 50.99.255.25450.99.255.25532,766
20150.100.0.0/1750.100.0.1 to 50.100.127.25450.100.127.25532,766
20250.100.128.0/1750.100.128.1 to 50.100.255.25450.100.255.25532,766
20350.101.0.0/1750.101.0.1 to 50.101.127.25450.101.127.25532,766
20450.101.128.0/1750.101.128.1 to 50.101.255.25450.101.255.25532,766
20550.102.0.0/1750.102.0.1 to 50.102.127.25450.102.127.25532,766
20650.102.128.0/1750.102.128.1 to 50.102.255.25450.102.255.25532,766
20750.103.0.0/1750.103.0.1 to 50.103.127.25450.103.127.25532,766
20850.103.128.0/1750.103.128.1 to 50.103.255.25450.103.255.25532,766
20950.104.0.0/1750.104.0.1 to 50.104.127.25450.104.127.25532,766
21050.104.128.0/1750.104.128.1 to 50.104.255.25450.104.255.25532,766
21150.105.0.0/1750.105.0.1 to 50.105.127.25450.105.127.25532,766
21250.105.128.0/1750.105.128.1 to 50.105.255.25450.105.255.25532,766
21350.106.0.0/1750.106.0.1 to 50.106.127.25450.106.127.25532,766
21450.106.128.0/1750.106.128.1 to 50.106.255.25450.106.255.25532,766
21550.107.0.0/1750.107.0.1 to 50.107.127.25450.107.127.25532,766
21650.107.128.0/1750.107.128.1 to 50.107.255.25450.107.255.25532,766
21750.108.0.0/1750.108.0.1 to 50.108.127.25450.108.127.25532,766
21850.108.128.0/1750.108.128.1 to 50.108.255.25450.108.255.25532,766
21950.109.0.0/1750.109.0.1 to 50.109.127.25450.109.127.25532,766
22050.109.128.0/1750.109.128.1 to 50.109.255.25450.109.255.25532,766
22150.110.0.0/1750.110.0.1 to 50.110.127.25450.110.127.25532,766
22250.110.128.0/1750.110.128.1 to 50.110.255.25450.110.255.25532,766
22350.111.0.0/1750.111.0.1 to 50.111.127.25450.111.127.25532,766
22450.111.128.0/1750.111.128.1 to 50.111.255.25450.111.255.25532,766
22550.112.0.0/1750.112.0.1 to 50.112.127.25450.112.127.25532,766
22650.112.128.0/1750.112.128.1 to 50.112.255.25450.112.255.25532,766
22750.113.0.0/1750.113.0.1 to 50.113.127.25450.113.127.25532,766
22850.113.128.0/1750.113.128.1 to 50.113.255.25450.113.255.25532,766
22950.114.0.0/1750.114.0.1 to 50.114.127.25450.114.127.25532,766
23050.114.128.0/1750.114.128.1 to 50.114.255.25450.114.255.25532,766
23150.115.0.0/1750.115.0.1 to 50.115.127.25450.115.127.25532,766
23250.115.128.0/1750.115.128.1 to 50.115.255.25450.115.255.25532,766
23350.116.0.0/1750.116.0.1 to 50.116.127.25450.116.127.25532,766
23450.116.128.0/1750.116.128.1 to 50.116.255.25450.116.255.25532,766
23550.117.0.0/1750.117.0.1 to 50.117.127.25450.117.127.25532,766
23650.117.128.0/1750.117.128.1 to 50.117.255.25450.117.255.25532,766
23750.118.0.0/1750.118.0.1 to 50.118.127.25450.118.127.25532,766
23850.118.128.0/1750.118.128.1 to 50.118.255.25450.118.255.25532,766
23950.119.0.0/1750.119.0.1 to 50.119.127.25450.119.127.25532,766
24050.119.128.0/1750.119.128.1 to 50.119.255.25450.119.255.25532,766
24150.120.0.0/1750.120.0.1 to 50.120.127.25450.120.127.25532,766
24250.120.128.0/1750.120.128.1 to 50.120.255.25450.120.255.25532,766
24350.121.0.0/1750.121.0.1 to 50.121.127.25450.121.127.25532,766
24450.121.128.0/1750.121.128.1 to 50.121.255.25450.121.255.25532,766
24550.122.0.0/1750.122.0.1 to 50.122.127.25450.122.127.25532,766
24650.122.128.0/1750.122.128.1 to 50.122.255.25450.122.255.25532,766
24750.123.0.0/1750.123.0.1 to 50.123.127.25450.123.127.25532,766
24850.123.128.0/1750.123.128.1 to 50.123.255.25450.123.255.25532,766
24950.124.0.0/1750.124.0.1 to 50.124.127.25450.124.127.25532,766
25050.124.128.0/1750.124.128.1 to 50.124.255.25450.124.255.25532,766
25150.125.0.0/1750.125.0.1 to 50.125.127.25450.125.127.25532,766
25250.125.128.0/1750.125.128.1 to 50.125.255.25450.125.255.25532,766
25350.126.0.0/1750.126.0.1 to 50.126.127.25450.126.127.25532,766
25450.126.128.0/1750.126.128.1 to 50.126.255.25450.126.255.25532,766
25550.127.0.0/1750.127.0.1 to 50.127.127.25450.127.127.25532,766
25650.127.128.0/1750.127.128.1 to 50.127.255.25450.127.255.25532,766

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.