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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.

Network44.0.0.0/7
Usable hosts33,554,430
Subnet mask254.0.0.0
Addresses33,554,432
Network address
44.0.0.0
Broadcast address
45.255.255.255
First usable
44.0.0.1
Last usable
45.255.255.254
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 2C000000 · Integer 738197504 to 771751935
Reverse DNS zones
44.in-addr.arpa
45.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
Address00101100.00000000.00000000.0000000044.0.0.0
Subnet mask11111110.00000000.00000000.00000000254.0.0.0
Network00101100.00000000.00000000.0000000044.0.0.0
Broadcast00101101.11111111.11111111.1111111145.255.255.255
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)

44.0.0.0/7 makes 1,024 subnets of /17; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
144.0.0.0/1744.0.0.1 to 44.0.127.25444.0.127.25532,766
244.0.128.0/1744.0.128.1 to 44.0.255.25444.0.255.25532,766
344.1.0.0/1744.1.0.1 to 44.1.127.25444.1.127.25532,766
444.1.128.0/1744.1.128.1 to 44.1.255.25444.1.255.25532,766
544.2.0.0/1744.2.0.1 to 44.2.127.25444.2.127.25532,766
644.2.128.0/1744.2.128.1 to 44.2.255.25444.2.255.25532,766
744.3.0.0/1744.3.0.1 to 44.3.127.25444.3.127.25532,766
844.3.128.0/1744.3.128.1 to 44.3.255.25444.3.255.25532,766
944.4.0.0/1744.4.0.1 to 44.4.127.25444.4.127.25532,766
1044.4.128.0/1744.4.128.1 to 44.4.255.25444.4.255.25532,766
1144.5.0.0/1744.5.0.1 to 44.5.127.25444.5.127.25532,766
1244.5.128.0/1744.5.128.1 to 44.5.255.25444.5.255.25532,766
1344.6.0.0/1744.6.0.1 to 44.6.127.25444.6.127.25532,766
1444.6.128.0/1744.6.128.1 to 44.6.255.25444.6.255.25532,766
1544.7.0.0/1744.7.0.1 to 44.7.127.25444.7.127.25532,766
1644.7.128.0/1744.7.128.1 to 44.7.255.25444.7.255.25532,766
1744.8.0.0/1744.8.0.1 to 44.8.127.25444.8.127.25532,766
1844.8.128.0/1744.8.128.1 to 44.8.255.25444.8.255.25532,766
1944.9.0.0/1744.9.0.1 to 44.9.127.25444.9.127.25532,766
2044.9.128.0/1744.9.128.1 to 44.9.255.25444.9.255.25532,766
2144.10.0.0/1744.10.0.1 to 44.10.127.25444.10.127.25532,766
2244.10.128.0/1744.10.128.1 to 44.10.255.25444.10.255.25532,766
2344.11.0.0/1744.11.0.1 to 44.11.127.25444.11.127.25532,766
2444.11.128.0/1744.11.128.1 to 44.11.255.25444.11.255.25532,766
2544.12.0.0/1744.12.0.1 to 44.12.127.25444.12.127.25532,766
2644.12.128.0/1744.12.128.1 to 44.12.255.25444.12.255.25532,766
2744.13.0.0/1744.13.0.1 to 44.13.127.25444.13.127.25532,766
2844.13.128.0/1744.13.128.1 to 44.13.255.25444.13.255.25532,766
2944.14.0.0/1744.14.0.1 to 44.14.127.25444.14.127.25532,766
3044.14.128.0/1744.14.128.1 to 44.14.255.25444.14.255.25532,766
3144.15.0.0/1744.15.0.1 to 44.15.127.25444.15.127.25532,766
3244.15.128.0/1744.15.128.1 to 44.15.255.25444.15.255.25532,766
3344.16.0.0/1744.16.0.1 to 44.16.127.25444.16.127.25532,766
3444.16.128.0/1744.16.128.1 to 44.16.255.25444.16.255.25532,766
3544.17.0.0/1744.17.0.1 to 44.17.127.25444.17.127.25532,766
3644.17.128.0/1744.17.128.1 to 44.17.255.25444.17.255.25532,766
3744.18.0.0/1744.18.0.1 to 44.18.127.25444.18.127.25532,766
3844.18.128.0/1744.18.128.1 to 44.18.255.25444.18.255.25532,766
3944.19.0.0/1744.19.0.1 to 44.19.127.25444.19.127.25532,766
4044.19.128.0/1744.19.128.1 to 44.19.255.25444.19.255.25532,766
4144.20.0.0/1744.20.0.1 to 44.20.127.25444.20.127.25532,766
4244.20.128.0/1744.20.128.1 to 44.20.255.25444.20.255.25532,766
4344.21.0.0/1744.21.0.1 to 44.21.127.25444.21.127.25532,766
4444.21.128.0/1744.21.128.1 to 44.21.255.25444.21.255.25532,766
4544.22.0.0/1744.22.0.1 to 44.22.127.25444.22.127.25532,766
4644.22.128.0/1744.22.128.1 to 44.22.255.25444.22.255.25532,766
4744.23.0.0/1744.23.0.1 to 44.23.127.25444.23.127.25532,766
4844.23.128.0/1744.23.128.1 to 44.23.255.25444.23.255.25532,766
4944.24.0.0/1744.24.0.1 to 44.24.127.25444.24.127.25532,766
5044.24.128.0/1744.24.128.1 to 44.24.255.25444.24.255.25532,766
5144.25.0.0/1744.25.0.1 to 44.25.127.25444.25.127.25532,766
5244.25.128.0/1744.25.128.1 to 44.25.255.25444.25.255.25532,766
5344.26.0.0/1744.26.0.1 to 44.26.127.25444.26.127.25532,766
5444.26.128.0/1744.26.128.1 to 44.26.255.25444.26.255.25532,766
5544.27.0.0/1744.27.0.1 to 44.27.127.25444.27.127.25532,766
5644.27.128.0/1744.27.128.1 to 44.27.255.25444.27.255.25532,766
5744.28.0.0/1744.28.0.1 to 44.28.127.25444.28.127.25532,766
5844.28.128.0/1744.28.128.1 to 44.28.255.25444.28.255.25532,766
5944.29.0.0/1744.29.0.1 to 44.29.127.25444.29.127.25532,766
6044.29.128.0/1744.29.128.1 to 44.29.255.25444.29.255.25532,766
6144.30.0.0/1744.30.0.1 to 44.30.127.25444.30.127.25532,766
6244.30.128.0/1744.30.128.1 to 44.30.255.25444.30.255.25532,766
6344.31.0.0/1744.31.0.1 to 44.31.127.25444.31.127.25532,766
6444.31.128.0/1744.31.128.1 to 44.31.255.25444.31.255.25532,766
6544.32.0.0/1744.32.0.1 to 44.32.127.25444.32.127.25532,766
6644.32.128.0/1744.32.128.1 to 44.32.255.25444.32.255.25532,766
6744.33.0.0/1744.33.0.1 to 44.33.127.25444.33.127.25532,766
6844.33.128.0/1744.33.128.1 to 44.33.255.25444.33.255.25532,766
6944.34.0.0/1744.34.0.1 to 44.34.127.25444.34.127.25532,766
7044.34.128.0/1744.34.128.1 to 44.34.255.25444.34.255.25532,766
7144.35.0.0/1744.35.0.1 to 44.35.127.25444.35.127.25532,766
7244.35.128.0/1744.35.128.1 to 44.35.255.25444.35.255.25532,766
7344.36.0.0/1744.36.0.1 to 44.36.127.25444.36.127.25532,766
7444.36.128.0/1744.36.128.1 to 44.36.255.25444.36.255.25532,766
7544.37.0.0/1744.37.0.1 to 44.37.127.25444.37.127.25532,766
7644.37.128.0/1744.37.128.1 to 44.37.255.25444.37.255.25532,766
7744.38.0.0/1744.38.0.1 to 44.38.127.25444.38.127.25532,766
7844.38.128.0/1744.38.128.1 to 44.38.255.25444.38.255.25532,766
7944.39.0.0/1744.39.0.1 to 44.39.127.25444.39.127.25532,766
8044.39.128.0/1744.39.128.1 to 44.39.255.25444.39.255.25532,766
8144.40.0.0/1744.40.0.1 to 44.40.127.25444.40.127.25532,766
8244.40.128.0/1744.40.128.1 to 44.40.255.25444.40.255.25532,766
8344.41.0.0/1744.41.0.1 to 44.41.127.25444.41.127.25532,766
8444.41.128.0/1744.41.128.1 to 44.41.255.25444.41.255.25532,766
8544.42.0.0/1744.42.0.1 to 44.42.127.25444.42.127.25532,766
8644.42.128.0/1744.42.128.1 to 44.42.255.25444.42.255.25532,766
8744.43.0.0/1744.43.0.1 to 44.43.127.25444.43.127.25532,766
8844.43.128.0/1744.43.128.1 to 44.43.255.25444.43.255.25532,766
8944.44.0.0/1744.44.0.1 to 44.44.127.25444.44.127.25532,766
9044.44.128.0/1744.44.128.1 to 44.44.255.25444.44.255.25532,766
9144.45.0.0/1744.45.0.1 to 44.45.127.25444.45.127.25532,766
9244.45.128.0/1744.45.128.1 to 44.45.255.25444.45.255.25532,766
9344.46.0.0/1744.46.0.1 to 44.46.127.25444.46.127.25532,766
9444.46.128.0/1744.46.128.1 to 44.46.255.25444.46.255.25532,766
9544.47.0.0/1744.47.0.1 to 44.47.127.25444.47.127.25532,766
9644.47.128.0/1744.47.128.1 to 44.47.255.25444.47.255.25532,766
9744.48.0.0/1744.48.0.1 to 44.48.127.25444.48.127.25532,766
9844.48.128.0/1744.48.128.1 to 44.48.255.25444.48.255.25532,766
9944.49.0.0/1744.49.0.1 to 44.49.127.25444.49.127.25532,766
10044.49.128.0/1744.49.128.1 to 44.49.255.25444.49.255.25532,766
10144.50.0.0/1744.50.0.1 to 44.50.127.25444.50.127.25532,766
10244.50.128.0/1744.50.128.1 to 44.50.255.25444.50.255.25532,766
10344.51.0.0/1744.51.0.1 to 44.51.127.25444.51.127.25532,766
10444.51.128.0/1744.51.128.1 to 44.51.255.25444.51.255.25532,766
10544.52.0.0/1744.52.0.1 to 44.52.127.25444.52.127.25532,766
10644.52.128.0/1744.52.128.1 to 44.52.255.25444.52.255.25532,766
10744.53.0.0/1744.53.0.1 to 44.53.127.25444.53.127.25532,766
10844.53.128.0/1744.53.128.1 to 44.53.255.25444.53.255.25532,766
10944.54.0.0/1744.54.0.1 to 44.54.127.25444.54.127.25532,766
11044.54.128.0/1744.54.128.1 to 44.54.255.25444.54.255.25532,766
11144.55.0.0/1744.55.0.1 to 44.55.127.25444.55.127.25532,766
11244.55.128.0/1744.55.128.1 to 44.55.255.25444.55.255.25532,766
11344.56.0.0/1744.56.0.1 to 44.56.127.25444.56.127.25532,766
11444.56.128.0/1744.56.128.1 to 44.56.255.25444.56.255.25532,766
11544.57.0.0/1744.57.0.1 to 44.57.127.25444.57.127.25532,766
11644.57.128.0/1744.57.128.1 to 44.57.255.25444.57.255.25532,766
11744.58.0.0/1744.58.0.1 to 44.58.127.25444.58.127.25532,766
11844.58.128.0/1744.58.128.1 to 44.58.255.25444.58.255.25532,766
11944.59.0.0/1744.59.0.1 to 44.59.127.25444.59.127.25532,766
12044.59.128.0/1744.59.128.1 to 44.59.255.25444.59.255.25532,766
12144.60.0.0/1744.60.0.1 to 44.60.127.25444.60.127.25532,766
12244.60.128.0/1744.60.128.1 to 44.60.255.25444.60.255.25532,766
12344.61.0.0/1744.61.0.1 to 44.61.127.25444.61.127.25532,766
12444.61.128.0/1744.61.128.1 to 44.61.255.25444.61.255.25532,766
12544.62.0.0/1744.62.0.1 to 44.62.127.25444.62.127.25532,766
12644.62.128.0/1744.62.128.1 to 44.62.255.25444.62.255.25532,766
12744.63.0.0/1744.63.0.1 to 44.63.127.25444.63.127.25532,766
12844.63.128.0/1744.63.128.1 to 44.63.255.25444.63.255.25532,766
12944.64.0.0/1744.64.0.1 to 44.64.127.25444.64.127.25532,766
13044.64.128.0/1744.64.128.1 to 44.64.255.25444.64.255.25532,766
13144.65.0.0/1744.65.0.1 to 44.65.127.25444.65.127.25532,766
13244.65.128.0/1744.65.128.1 to 44.65.255.25444.65.255.25532,766
13344.66.0.0/1744.66.0.1 to 44.66.127.25444.66.127.25532,766
13444.66.128.0/1744.66.128.1 to 44.66.255.25444.66.255.25532,766
13544.67.0.0/1744.67.0.1 to 44.67.127.25444.67.127.25532,766
13644.67.128.0/1744.67.128.1 to 44.67.255.25444.67.255.25532,766
13744.68.0.0/1744.68.0.1 to 44.68.127.25444.68.127.25532,766
13844.68.128.0/1744.68.128.1 to 44.68.255.25444.68.255.25532,766
13944.69.0.0/1744.69.0.1 to 44.69.127.25444.69.127.25532,766
14044.69.128.0/1744.69.128.1 to 44.69.255.25444.69.255.25532,766
14144.70.0.0/1744.70.0.1 to 44.70.127.25444.70.127.25532,766
14244.70.128.0/1744.70.128.1 to 44.70.255.25444.70.255.25532,766
14344.71.0.0/1744.71.0.1 to 44.71.127.25444.71.127.25532,766
14444.71.128.0/1744.71.128.1 to 44.71.255.25444.71.255.25532,766
14544.72.0.0/1744.72.0.1 to 44.72.127.25444.72.127.25532,766
14644.72.128.0/1744.72.128.1 to 44.72.255.25444.72.255.25532,766
14744.73.0.0/1744.73.0.1 to 44.73.127.25444.73.127.25532,766
14844.73.128.0/1744.73.128.1 to 44.73.255.25444.73.255.25532,766
14944.74.0.0/1744.74.0.1 to 44.74.127.25444.74.127.25532,766
15044.74.128.0/1744.74.128.1 to 44.74.255.25444.74.255.25532,766
15144.75.0.0/1744.75.0.1 to 44.75.127.25444.75.127.25532,766
15244.75.128.0/1744.75.128.1 to 44.75.255.25444.75.255.25532,766
15344.76.0.0/1744.76.0.1 to 44.76.127.25444.76.127.25532,766
15444.76.128.0/1744.76.128.1 to 44.76.255.25444.76.255.25532,766
15544.77.0.0/1744.77.0.1 to 44.77.127.25444.77.127.25532,766
15644.77.128.0/1744.77.128.1 to 44.77.255.25444.77.255.25532,766
15744.78.0.0/1744.78.0.1 to 44.78.127.25444.78.127.25532,766
15844.78.128.0/1744.78.128.1 to 44.78.255.25444.78.255.25532,766
15944.79.0.0/1744.79.0.1 to 44.79.127.25444.79.127.25532,766
16044.79.128.0/1744.79.128.1 to 44.79.255.25444.79.255.25532,766
16144.80.0.0/1744.80.0.1 to 44.80.127.25444.80.127.25532,766
16244.80.128.0/1744.80.128.1 to 44.80.255.25444.80.255.25532,766
16344.81.0.0/1744.81.0.1 to 44.81.127.25444.81.127.25532,766
16444.81.128.0/1744.81.128.1 to 44.81.255.25444.81.255.25532,766
16544.82.0.0/1744.82.0.1 to 44.82.127.25444.82.127.25532,766
16644.82.128.0/1744.82.128.1 to 44.82.255.25444.82.255.25532,766
16744.83.0.0/1744.83.0.1 to 44.83.127.25444.83.127.25532,766
16844.83.128.0/1744.83.128.1 to 44.83.255.25444.83.255.25532,766
16944.84.0.0/1744.84.0.1 to 44.84.127.25444.84.127.25532,766
17044.84.128.0/1744.84.128.1 to 44.84.255.25444.84.255.25532,766
17144.85.0.0/1744.85.0.1 to 44.85.127.25444.85.127.25532,766
17244.85.128.0/1744.85.128.1 to 44.85.255.25444.85.255.25532,766
17344.86.0.0/1744.86.0.1 to 44.86.127.25444.86.127.25532,766
17444.86.128.0/1744.86.128.1 to 44.86.255.25444.86.255.25532,766
17544.87.0.0/1744.87.0.1 to 44.87.127.25444.87.127.25532,766
17644.87.128.0/1744.87.128.1 to 44.87.255.25444.87.255.25532,766
17744.88.0.0/1744.88.0.1 to 44.88.127.25444.88.127.25532,766
17844.88.128.0/1744.88.128.1 to 44.88.255.25444.88.255.25532,766
17944.89.0.0/1744.89.0.1 to 44.89.127.25444.89.127.25532,766
18044.89.128.0/1744.89.128.1 to 44.89.255.25444.89.255.25532,766
18144.90.0.0/1744.90.0.1 to 44.90.127.25444.90.127.25532,766
18244.90.128.0/1744.90.128.1 to 44.90.255.25444.90.255.25532,766
18344.91.0.0/1744.91.0.1 to 44.91.127.25444.91.127.25532,766
18444.91.128.0/1744.91.128.1 to 44.91.255.25444.91.255.25532,766
18544.92.0.0/1744.92.0.1 to 44.92.127.25444.92.127.25532,766
18644.92.128.0/1744.92.128.1 to 44.92.255.25444.92.255.25532,766
18744.93.0.0/1744.93.0.1 to 44.93.127.25444.93.127.25532,766
18844.93.128.0/1744.93.128.1 to 44.93.255.25444.93.255.25532,766
18944.94.0.0/1744.94.0.1 to 44.94.127.25444.94.127.25532,766
19044.94.128.0/1744.94.128.1 to 44.94.255.25444.94.255.25532,766
19144.95.0.0/1744.95.0.1 to 44.95.127.25444.95.127.25532,766
19244.95.128.0/1744.95.128.1 to 44.95.255.25444.95.255.25532,766
19344.96.0.0/1744.96.0.1 to 44.96.127.25444.96.127.25532,766
19444.96.128.0/1744.96.128.1 to 44.96.255.25444.96.255.25532,766
19544.97.0.0/1744.97.0.1 to 44.97.127.25444.97.127.25532,766
19644.97.128.0/1744.97.128.1 to 44.97.255.25444.97.255.25532,766
19744.98.0.0/1744.98.0.1 to 44.98.127.25444.98.127.25532,766
19844.98.128.0/1744.98.128.1 to 44.98.255.25444.98.255.25532,766
19944.99.0.0/1744.99.0.1 to 44.99.127.25444.99.127.25532,766
20044.99.128.0/1744.99.128.1 to 44.99.255.25444.99.255.25532,766
20144.100.0.0/1744.100.0.1 to 44.100.127.25444.100.127.25532,766
20244.100.128.0/1744.100.128.1 to 44.100.255.25444.100.255.25532,766
20344.101.0.0/1744.101.0.1 to 44.101.127.25444.101.127.25532,766
20444.101.128.0/1744.101.128.1 to 44.101.255.25444.101.255.25532,766
20544.102.0.0/1744.102.0.1 to 44.102.127.25444.102.127.25532,766
20644.102.128.0/1744.102.128.1 to 44.102.255.25444.102.255.25532,766
20744.103.0.0/1744.103.0.1 to 44.103.127.25444.103.127.25532,766
20844.103.128.0/1744.103.128.1 to 44.103.255.25444.103.255.25532,766
20944.104.0.0/1744.104.0.1 to 44.104.127.25444.104.127.25532,766
21044.104.128.0/1744.104.128.1 to 44.104.255.25444.104.255.25532,766
21144.105.0.0/1744.105.0.1 to 44.105.127.25444.105.127.25532,766
21244.105.128.0/1744.105.128.1 to 44.105.255.25444.105.255.25532,766
21344.106.0.0/1744.106.0.1 to 44.106.127.25444.106.127.25532,766
21444.106.128.0/1744.106.128.1 to 44.106.255.25444.106.255.25532,766
21544.107.0.0/1744.107.0.1 to 44.107.127.25444.107.127.25532,766
21644.107.128.0/1744.107.128.1 to 44.107.255.25444.107.255.25532,766
21744.108.0.0/1744.108.0.1 to 44.108.127.25444.108.127.25532,766
21844.108.128.0/1744.108.128.1 to 44.108.255.25444.108.255.25532,766
21944.109.0.0/1744.109.0.1 to 44.109.127.25444.109.127.25532,766
22044.109.128.0/1744.109.128.1 to 44.109.255.25444.109.255.25532,766
22144.110.0.0/1744.110.0.1 to 44.110.127.25444.110.127.25532,766
22244.110.128.0/1744.110.128.1 to 44.110.255.25444.110.255.25532,766
22344.111.0.0/1744.111.0.1 to 44.111.127.25444.111.127.25532,766
22444.111.128.0/1744.111.128.1 to 44.111.255.25444.111.255.25532,766
22544.112.0.0/1744.112.0.1 to 44.112.127.25444.112.127.25532,766
22644.112.128.0/1744.112.128.1 to 44.112.255.25444.112.255.25532,766
22744.113.0.0/1744.113.0.1 to 44.113.127.25444.113.127.25532,766
22844.113.128.0/1744.113.128.1 to 44.113.255.25444.113.255.25532,766
22944.114.0.0/1744.114.0.1 to 44.114.127.25444.114.127.25532,766
23044.114.128.0/1744.114.128.1 to 44.114.255.25444.114.255.25532,766
23144.115.0.0/1744.115.0.1 to 44.115.127.25444.115.127.25532,766
23244.115.128.0/1744.115.128.1 to 44.115.255.25444.115.255.25532,766
23344.116.0.0/1744.116.0.1 to 44.116.127.25444.116.127.25532,766
23444.116.128.0/1744.116.128.1 to 44.116.255.25444.116.255.25532,766
23544.117.0.0/1744.117.0.1 to 44.117.127.25444.117.127.25532,766
23644.117.128.0/1744.117.128.1 to 44.117.255.25444.117.255.25532,766
23744.118.0.0/1744.118.0.1 to 44.118.127.25444.118.127.25532,766
23844.118.128.0/1744.118.128.1 to 44.118.255.25444.118.255.25532,766
23944.119.0.0/1744.119.0.1 to 44.119.127.25444.119.127.25532,766
24044.119.128.0/1744.119.128.1 to 44.119.255.25444.119.255.25532,766
24144.120.0.0/1744.120.0.1 to 44.120.127.25444.120.127.25532,766
24244.120.128.0/1744.120.128.1 to 44.120.255.25444.120.255.25532,766
24344.121.0.0/1744.121.0.1 to 44.121.127.25444.121.127.25532,766
24444.121.128.0/1744.121.128.1 to 44.121.255.25444.121.255.25532,766
24544.122.0.0/1744.122.0.1 to 44.122.127.25444.122.127.25532,766
24644.122.128.0/1744.122.128.1 to 44.122.255.25444.122.255.25532,766
24744.123.0.0/1744.123.0.1 to 44.123.127.25444.123.127.25532,766
24844.123.128.0/1744.123.128.1 to 44.123.255.25444.123.255.25532,766
24944.124.0.0/1744.124.0.1 to 44.124.127.25444.124.127.25532,766
25044.124.128.0/1744.124.128.1 to 44.124.255.25444.124.255.25532,766
25144.125.0.0/1744.125.0.1 to 44.125.127.25444.125.127.25532,766
25244.125.128.0/1744.125.128.1 to 44.125.255.25444.125.255.25532,766
25344.126.0.0/1744.126.0.1 to 44.126.127.25444.126.127.25532,766
25444.126.128.0/1744.126.128.1 to 44.126.255.25444.126.255.25532,766
25544.127.0.0/1744.127.0.1 to 44.127.127.25444.127.127.25532,766
25644.127.128.0/1744.127.128.1 to 44.127.255.25444.127.255.25532,766

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.