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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.

Network41.0.0.0/9
Usable hosts8,388,606
Subnet mask255.128.0.0
Addresses8,388,608
Network address
41.0.0.0
Broadcast address
41.127.255.255
First usable
41.0.0.1
Last usable
41.127.255.254
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 29000000 · Integer 687865856 to 696254463
Reverse DNS zones
0.41.in-addr.arpa
1.41.in-addr.arpa
2.41.in-addr.arpa
3.41.in-addr.arpa
4.41.in-addr.arpa
5.41.in-addr.arpa
6.41.in-addr.arpa
7.41.in-addr.arpa
8.41.in-addr.arpa
9.41.in-addr.arpa
10.41.in-addr.arpa
11.41.in-addr.arpa
12.41.in-addr.arpa
13.41.in-addr.arpa
14.41.in-addr.arpa
15.41.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
Address00101001.00000000.00000000.0000000041.0.0.0
Subnet mask11111111.10000000.00000000.00000000255.128.0.0
Network00101001.00000000.00000000.0000000041.0.0.0
Broadcast00101001.01111111.11111111.1111111141.127.255.255
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)

41.0.0.0/9 makes 256 subnets of /17.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
141.0.0.0/1741.0.0.1 to 41.0.127.25441.0.127.25532,766
241.0.128.0/1741.0.128.1 to 41.0.255.25441.0.255.25532,766
341.1.0.0/1741.1.0.1 to 41.1.127.25441.1.127.25532,766
441.1.128.0/1741.1.128.1 to 41.1.255.25441.1.255.25532,766
541.2.0.0/1741.2.0.1 to 41.2.127.25441.2.127.25532,766
641.2.128.0/1741.2.128.1 to 41.2.255.25441.2.255.25532,766
741.3.0.0/1741.3.0.1 to 41.3.127.25441.3.127.25532,766
841.3.128.0/1741.3.128.1 to 41.3.255.25441.3.255.25532,766
941.4.0.0/1741.4.0.1 to 41.4.127.25441.4.127.25532,766
1041.4.128.0/1741.4.128.1 to 41.4.255.25441.4.255.25532,766
1141.5.0.0/1741.5.0.1 to 41.5.127.25441.5.127.25532,766
1241.5.128.0/1741.5.128.1 to 41.5.255.25441.5.255.25532,766
1341.6.0.0/1741.6.0.1 to 41.6.127.25441.6.127.25532,766
1441.6.128.0/1741.6.128.1 to 41.6.255.25441.6.255.25532,766
1541.7.0.0/1741.7.0.1 to 41.7.127.25441.7.127.25532,766
1641.7.128.0/1741.7.128.1 to 41.7.255.25441.7.255.25532,766
1741.8.0.0/1741.8.0.1 to 41.8.127.25441.8.127.25532,766
1841.8.128.0/1741.8.128.1 to 41.8.255.25441.8.255.25532,766
1941.9.0.0/1741.9.0.1 to 41.9.127.25441.9.127.25532,766
2041.9.128.0/1741.9.128.1 to 41.9.255.25441.9.255.25532,766
2141.10.0.0/1741.10.0.1 to 41.10.127.25441.10.127.25532,766
2241.10.128.0/1741.10.128.1 to 41.10.255.25441.10.255.25532,766
2341.11.0.0/1741.11.0.1 to 41.11.127.25441.11.127.25532,766
2441.11.128.0/1741.11.128.1 to 41.11.255.25441.11.255.25532,766
2541.12.0.0/1741.12.0.1 to 41.12.127.25441.12.127.25532,766
2641.12.128.0/1741.12.128.1 to 41.12.255.25441.12.255.25532,766
2741.13.0.0/1741.13.0.1 to 41.13.127.25441.13.127.25532,766
2841.13.128.0/1741.13.128.1 to 41.13.255.25441.13.255.25532,766
2941.14.0.0/1741.14.0.1 to 41.14.127.25441.14.127.25532,766
3041.14.128.0/1741.14.128.1 to 41.14.255.25441.14.255.25532,766
3141.15.0.0/1741.15.0.1 to 41.15.127.25441.15.127.25532,766
3241.15.128.0/1741.15.128.1 to 41.15.255.25441.15.255.25532,766
3341.16.0.0/1741.16.0.1 to 41.16.127.25441.16.127.25532,766
3441.16.128.0/1741.16.128.1 to 41.16.255.25441.16.255.25532,766
3541.17.0.0/1741.17.0.1 to 41.17.127.25441.17.127.25532,766
3641.17.128.0/1741.17.128.1 to 41.17.255.25441.17.255.25532,766
3741.18.0.0/1741.18.0.1 to 41.18.127.25441.18.127.25532,766
3841.18.128.0/1741.18.128.1 to 41.18.255.25441.18.255.25532,766
3941.19.0.0/1741.19.0.1 to 41.19.127.25441.19.127.25532,766
4041.19.128.0/1741.19.128.1 to 41.19.255.25441.19.255.25532,766
4141.20.0.0/1741.20.0.1 to 41.20.127.25441.20.127.25532,766
4241.20.128.0/1741.20.128.1 to 41.20.255.25441.20.255.25532,766
4341.21.0.0/1741.21.0.1 to 41.21.127.25441.21.127.25532,766
4441.21.128.0/1741.21.128.1 to 41.21.255.25441.21.255.25532,766
4541.22.0.0/1741.22.0.1 to 41.22.127.25441.22.127.25532,766
4641.22.128.0/1741.22.128.1 to 41.22.255.25441.22.255.25532,766
4741.23.0.0/1741.23.0.1 to 41.23.127.25441.23.127.25532,766
4841.23.128.0/1741.23.128.1 to 41.23.255.25441.23.255.25532,766
4941.24.0.0/1741.24.0.1 to 41.24.127.25441.24.127.25532,766
5041.24.128.0/1741.24.128.1 to 41.24.255.25441.24.255.25532,766
5141.25.0.0/1741.25.0.1 to 41.25.127.25441.25.127.25532,766
5241.25.128.0/1741.25.128.1 to 41.25.255.25441.25.255.25532,766
5341.26.0.0/1741.26.0.1 to 41.26.127.25441.26.127.25532,766
5441.26.128.0/1741.26.128.1 to 41.26.255.25441.26.255.25532,766
5541.27.0.0/1741.27.0.1 to 41.27.127.25441.27.127.25532,766
5641.27.128.0/1741.27.128.1 to 41.27.255.25441.27.255.25532,766
5741.28.0.0/1741.28.0.1 to 41.28.127.25441.28.127.25532,766
5841.28.128.0/1741.28.128.1 to 41.28.255.25441.28.255.25532,766
5941.29.0.0/1741.29.0.1 to 41.29.127.25441.29.127.25532,766
6041.29.128.0/1741.29.128.1 to 41.29.255.25441.29.255.25532,766
6141.30.0.0/1741.30.0.1 to 41.30.127.25441.30.127.25532,766
6241.30.128.0/1741.30.128.1 to 41.30.255.25441.30.255.25532,766
6341.31.0.0/1741.31.0.1 to 41.31.127.25441.31.127.25532,766
6441.31.128.0/1741.31.128.1 to 41.31.255.25441.31.255.25532,766
6541.32.0.0/1741.32.0.1 to 41.32.127.25441.32.127.25532,766
6641.32.128.0/1741.32.128.1 to 41.32.255.25441.32.255.25532,766
6741.33.0.0/1741.33.0.1 to 41.33.127.25441.33.127.25532,766
6841.33.128.0/1741.33.128.1 to 41.33.255.25441.33.255.25532,766
6941.34.0.0/1741.34.0.1 to 41.34.127.25441.34.127.25532,766
7041.34.128.0/1741.34.128.1 to 41.34.255.25441.34.255.25532,766
7141.35.0.0/1741.35.0.1 to 41.35.127.25441.35.127.25532,766
7241.35.128.0/1741.35.128.1 to 41.35.255.25441.35.255.25532,766
7341.36.0.0/1741.36.0.1 to 41.36.127.25441.36.127.25532,766
7441.36.128.0/1741.36.128.1 to 41.36.255.25441.36.255.25532,766
7541.37.0.0/1741.37.0.1 to 41.37.127.25441.37.127.25532,766
7641.37.128.0/1741.37.128.1 to 41.37.255.25441.37.255.25532,766
7741.38.0.0/1741.38.0.1 to 41.38.127.25441.38.127.25532,766
7841.38.128.0/1741.38.128.1 to 41.38.255.25441.38.255.25532,766
7941.39.0.0/1741.39.0.1 to 41.39.127.25441.39.127.25532,766
8041.39.128.0/1741.39.128.1 to 41.39.255.25441.39.255.25532,766
8141.40.0.0/1741.40.0.1 to 41.40.127.25441.40.127.25532,766
8241.40.128.0/1741.40.128.1 to 41.40.255.25441.40.255.25532,766
8341.41.0.0/1741.41.0.1 to 41.41.127.25441.41.127.25532,766
8441.41.128.0/1741.41.128.1 to 41.41.255.25441.41.255.25532,766
8541.42.0.0/1741.42.0.1 to 41.42.127.25441.42.127.25532,766
8641.42.128.0/1741.42.128.1 to 41.42.255.25441.42.255.25532,766
8741.43.0.0/1741.43.0.1 to 41.43.127.25441.43.127.25532,766
8841.43.128.0/1741.43.128.1 to 41.43.255.25441.43.255.25532,766
8941.44.0.0/1741.44.0.1 to 41.44.127.25441.44.127.25532,766
9041.44.128.0/1741.44.128.1 to 41.44.255.25441.44.255.25532,766
9141.45.0.0/1741.45.0.1 to 41.45.127.25441.45.127.25532,766
9241.45.128.0/1741.45.128.1 to 41.45.255.25441.45.255.25532,766
9341.46.0.0/1741.46.0.1 to 41.46.127.25441.46.127.25532,766
9441.46.128.0/1741.46.128.1 to 41.46.255.25441.46.255.25532,766
9541.47.0.0/1741.47.0.1 to 41.47.127.25441.47.127.25532,766
9641.47.128.0/1741.47.128.1 to 41.47.255.25441.47.255.25532,766
9741.48.0.0/1741.48.0.1 to 41.48.127.25441.48.127.25532,766
9841.48.128.0/1741.48.128.1 to 41.48.255.25441.48.255.25532,766
9941.49.0.0/1741.49.0.1 to 41.49.127.25441.49.127.25532,766
10041.49.128.0/1741.49.128.1 to 41.49.255.25441.49.255.25532,766
10141.50.0.0/1741.50.0.1 to 41.50.127.25441.50.127.25532,766
10241.50.128.0/1741.50.128.1 to 41.50.255.25441.50.255.25532,766
10341.51.0.0/1741.51.0.1 to 41.51.127.25441.51.127.25532,766
10441.51.128.0/1741.51.128.1 to 41.51.255.25441.51.255.25532,766
10541.52.0.0/1741.52.0.1 to 41.52.127.25441.52.127.25532,766
10641.52.128.0/1741.52.128.1 to 41.52.255.25441.52.255.25532,766
10741.53.0.0/1741.53.0.1 to 41.53.127.25441.53.127.25532,766
10841.53.128.0/1741.53.128.1 to 41.53.255.25441.53.255.25532,766
10941.54.0.0/1741.54.0.1 to 41.54.127.25441.54.127.25532,766
11041.54.128.0/1741.54.128.1 to 41.54.255.25441.54.255.25532,766
11141.55.0.0/1741.55.0.1 to 41.55.127.25441.55.127.25532,766
11241.55.128.0/1741.55.128.1 to 41.55.255.25441.55.255.25532,766
11341.56.0.0/1741.56.0.1 to 41.56.127.25441.56.127.25532,766
11441.56.128.0/1741.56.128.1 to 41.56.255.25441.56.255.25532,766
11541.57.0.0/1741.57.0.1 to 41.57.127.25441.57.127.25532,766
11641.57.128.0/1741.57.128.1 to 41.57.255.25441.57.255.25532,766
11741.58.0.0/1741.58.0.1 to 41.58.127.25441.58.127.25532,766
11841.58.128.0/1741.58.128.1 to 41.58.255.25441.58.255.25532,766
11941.59.0.0/1741.59.0.1 to 41.59.127.25441.59.127.25532,766
12041.59.128.0/1741.59.128.1 to 41.59.255.25441.59.255.25532,766
12141.60.0.0/1741.60.0.1 to 41.60.127.25441.60.127.25532,766
12241.60.128.0/1741.60.128.1 to 41.60.255.25441.60.255.25532,766
12341.61.0.0/1741.61.0.1 to 41.61.127.25441.61.127.25532,766
12441.61.128.0/1741.61.128.1 to 41.61.255.25441.61.255.25532,766
12541.62.0.0/1741.62.0.1 to 41.62.127.25441.62.127.25532,766
12641.62.128.0/1741.62.128.1 to 41.62.255.25441.62.255.25532,766
12741.63.0.0/1741.63.0.1 to 41.63.127.25441.63.127.25532,766
12841.63.128.0/1741.63.128.1 to 41.63.255.25441.63.255.25532,766
12941.64.0.0/1741.64.0.1 to 41.64.127.25441.64.127.25532,766
13041.64.128.0/1741.64.128.1 to 41.64.255.25441.64.255.25532,766
13141.65.0.0/1741.65.0.1 to 41.65.127.25441.65.127.25532,766
13241.65.128.0/1741.65.128.1 to 41.65.255.25441.65.255.25532,766
13341.66.0.0/1741.66.0.1 to 41.66.127.25441.66.127.25532,766
13441.66.128.0/1741.66.128.1 to 41.66.255.25441.66.255.25532,766
13541.67.0.0/1741.67.0.1 to 41.67.127.25441.67.127.25532,766
13641.67.128.0/1741.67.128.1 to 41.67.255.25441.67.255.25532,766
13741.68.0.0/1741.68.0.1 to 41.68.127.25441.68.127.25532,766
13841.68.128.0/1741.68.128.1 to 41.68.255.25441.68.255.25532,766
13941.69.0.0/1741.69.0.1 to 41.69.127.25441.69.127.25532,766
14041.69.128.0/1741.69.128.1 to 41.69.255.25441.69.255.25532,766
14141.70.0.0/1741.70.0.1 to 41.70.127.25441.70.127.25532,766
14241.70.128.0/1741.70.128.1 to 41.70.255.25441.70.255.25532,766
14341.71.0.0/1741.71.0.1 to 41.71.127.25441.71.127.25532,766
14441.71.128.0/1741.71.128.1 to 41.71.255.25441.71.255.25532,766
14541.72.0.0/1741.72.0.1 to 41.72.127.25441.72.127.25532,766
14641.72.128.0/1741.72.128.1 to 41.72.255.25441.72.255.25532,766
14741.73.0.0/1741.73.0.1 to 41.73.127.25441.73.127.25532,766
14841.73.128.0/1741.73.128.1 to 41.73.255.25441.73.255.25532,766
14941.74.0.0/1741.74.0.1 to 41.74.127.25441.74.127.25532,766
15041.74.128.0/1741.74.128.1 to 41.74.255.25441.74.255.25532,766
15141.75.0.0/1741.75.0.1 to 41.75.127.25441.75.127.25532,766
15241.75.128.0/1741.75.128.1 to 41.75.255.25441.75.255.25532,766
15341.76.0.0/1741.76.0.1 to 41.76.127.25441.76.127.25532,766
15441.76.128.0/1741.76.128.1 to 41.76.255.25441.76.255.25532,766
15541.77.0.0/1741.77.0.1 to 41.77.127.25441.77.127.25532,766
15641.77.128.0/1741.77.128.1 to 41.77.255.25441.77.255.25532,766
15741.78.0.0/1741.78.0.1 to 41.78.127.25441.78.127.25532,766
15841.78.128.0/1741.78.128.1 to 41.78.255.25441.78.255.25532,766
15941.79.0.0/1741.79.0.1 to 41.79.127.25441.79.127.25532,766
16041.79.128.0/1741.79.128.1 to 41.79.255.25441.79.255.25532,766
16141.80.0.0/1741.80.0.1 to 41.80.127.25441.80.127.25532,766
16241.80.128.0/1741.80.128.1 to 41.80.255.25441.80.255.25532,766
16341.81.0.0/1741.81.0.1 to 41.81.127.25441.81.127.25532,766
16441.81.128.0/1741.81.128.1 to 41.81.255.25441.81.255.25532,766
16541.82.0.0/1741.82.0.1 to 41.82.127.25441.82.127.25532,766
16641.82.128.0/1741.82.128.1 to 41.82.255.25441.82.255.25532,766
16741.83.0.0/1741.83.0.1 to 41.83.127.25441.83.127.25532,766
16841.83.128.0/1741.83.128.1 to 41.83.255.25441.83.255.25532,766
16941.84.0.0/1741.84.0.1 to 41.84.127.25441.84.127.25532,766
17041.84.128.0/1741.84.128.1 to 41.84.255.25441.84.255.25532,766
17141.85.0.0/1741.85.0.1 to 41.85.127.25441.85.127.25532,766
17241.85.128.0/1741.85.128.1 to 41.85.255.25441.85.255.25532,766
17341.86.0.0/1741.86.0.1 to 41.86.127.25441.86.127.25532,766
17441.86.128.0/1741.86.128.1 to 41.86.255.25441.86.255.25532,766
17541.87.0.0/1741.87.0.1 to 41.87.127.25441.87.127.25532,766
17641.87.128.0/1741.87.128.1 to 41.87.255.25441.87.255.25532,766
17741.88.0.0/1741.88.0.1 to 41.88.127.25441.88.127.25532,766
17841.88.128.0/1741.88.128.1 to 41.88.255.25441.88.255.25532,766
17941.89.0.0/1741.89.0.1 to 41.89.127.25441.89.127.25532,766
18041.89.128.0/1741.89.128.1 to 41.89.255.25441.89.255.25532,766
18141.90.0.0/1741.90.0.1 to 41.90.127.25441.90.127.25532,766
18241.90.128.0/1741.90.128.1 to 41.90.255.25441.90.255.25532,766
18341.91.0.0/1741.91.0.1 to 41.91.127.25441.91.127.25532,766
18441.91.128.0/1741.91.128.1 to 41.91.255.25441.91.255.25532,766
18541.92.0.0/1741.92.0.1 to 41.92.127.25441.92.127.25532,766
18641.92.128.0/1741.92.128.1 to 41.92.255.25441.92.255.25532,766
18741.93.0.0/1741.93.0.1 to 41.93.127.25441.93.127.25532,766
18841.93.128.0/1741.93.128.1 to 41.93.255.25441.93.255.25532,766
18941.94.0.0/1741.94.0.1 to 41.94.127.25441.94.127.25532,766
19041.94.128.0/1741.94.128.1 to 41.94.255.25441.94.255.25532,766
19141.95.0.0/1741.95.0.1 to 41.95.127.25441.95.127.25532,766
19241.95.128.0/1741.95.128.1 to 41.95.255.25441.95.255.25532,766
19341.96.0.0/1741.96.0.1 to 41.96.127.25441.96.127.25532,766
19441.96.128.0/1741.96.128.1 to 41.96.255.25441.96.255.25532,766
19541.97.0.0/1741.97.0.1 to 41.97.127.25441.97.127.25532,766
19641.97.128.0/1741.97.128.1 to 41.97.255.25441.97.255.25532,766
19741.98.0.0/1741.98.0.1 to 41.98.127.25441.98.127.25532,766
19841.98.128.0/1741.98.128.1 to 41.98.255.25441.98.255.25532,766
19941.99.0.0/1741.99.0.1 to 41.99.127.25441.99.127.25532,766
20041.99.128.0/1741.99.128.1 to 41.99.255.25441.99.255.25532,766
20141.100.0.0/1741.100.0.1 to 41.100.127.25441.100.127.25532,766
20241.100.128.0/1741.100.128.1 to 41.100.255.25441.100.255.25532,766
20341.101.0.0/1741.101.0.1 to 41.101.127.25441.101.127.25532,766
20441.101.128.0/1741.101.128.1 to 41.101.255.25441.101.255.25532,766
20541.102.0.0/1741.102.0.1 to 41.102.127.25441.102.127.25532,766
20641.102.128.0/1741.102.128.1 to 41.102.255.25441.102.255.25532,766
20741.103.0.0/1741.103.0.1 to 41.103.127.25441.103.127.25532,766
20841.103.128.0/1741.103.128.1 to 41.103.255.25441.103.255.25532,766
20941.104.0.0/1741.104.0.1 to 41.104.127.25441.104.127.25532,766
21041.104.128.0/1741.104.128.1 to 41.104.255.25441.104.255.25532,766
21141.105.0.0/1741.105.0.1 to 41.105.127.25441.105.127.25532,766
21241.105.128.0/1741.105.128.1 to 41.105.255.25441.105.255.25532,766
21341.106.0.0/1741.106.0.1 to 41.106.127.25441.106.127.25532,766
21441.106.128.0/1741.106.128.1 to 41.106.255.25441.106.255.25532,766
21541.107.0.0/1741.107.0.1 to 41.107.127.25441.107.127.25532,766
21641.107.128.0/1741.107.128.1 to 41.107.255.25441.107.255.25532,766
21741.108.0.0/1741.108.0.1 to 41.108.127.25441.108.127.25532,766
21841.108.128.0/1741.108.128.1 to 41.108.255.25441.108.255.25532,766
21941.109.0.0/1741.109.0.1 to 41.109.127.25441.109.127.25532,766
22041.109.128.0/1741.109.128.1 to 41.109.255.25441.109.255.25532,766
22141.110.0.0/1741.110.0.1 to 41.110.127.25441.110.127.25532,766
22241.110.128.0/1741.110.128.1 to 41.110.255.25441.110.255.25532,766
22341.111.0.0/1741.111.0.1 to 41.111.127.25441.111.127.25532,766
22441.111.128.0/1741.111.128.1 to 41.111.255.25441.111.255.25532,766
22541.112.0.0/1741.112.0.1 to 41.112.127.25441.112.127.25532,766
22641.112.128.0/1741.112.128.1 to 41.112.255.25441.112.255.25532,766
22741.113.0.0/1741.113.0.1 to 41.113.127.25441.113.127.25532,766
22841.113.128.0/1741.113.128.1 to 41.113.255.25441.113.255.25532,766
22941.114.0.0/1741.114.0.1 to 41.114.127.25441.114.127.25532,766
23041.114.128.0/1741.114.128.1 to 41.114.255.25441.114.255.25532,766
23141.115.0.0/1741.115.0.1 to 41.115.127.25441.115.127.25532,766
23241.115.128.0/1741.115.128.1 to 41.115.255.25441.115.255.25532,766
23341.116.0.0/1741.116.0.1 to 41.116.127.25441.116.127.25532,766
23441.116.128.0/1741.116.128.1 to 41.116.255.25441.116.255.25532,766
23541.117.0.0/1741.117.0.1 to 41.117.127.25441.117.127.25532,766
23641.117.128.0/1741.117.128.1 to 41.117.255.25441.117.255.25532,766
23741.118.0.0/1741.118.0.1 to 41.118.127.25441.118.127.25532,766
23841.118.128.0/1741.118.128.1 to 41.118.255.25441.118.255.25532,766
23941.119.0.0/1741.119.0.1 to 41.119.127.25441.119.127.25532,766
24041.119.128.0/1741.119.128.1 to 41.119.255.25441.119.255.25532,766
24141.120.0.0/1741.120.0.1 to 41.120.127.25441.120.127.25532,766
24241.120.128.0/1741.120.128.1 to 41.120.255.25441.120.255.25532,766
24341.121.0.0/1741.121.0.1 to 41.121.127.25441.121.127.25532,766
24441.121.128.0/1741.121.128.1 to 41.121.255.25441.121.255.25532,766
24541.122.0.0/1741.122.0.1 to 41.122.127.25441.122.127.25532,766
24641.122.128.0/1741.122.128.1 to 41.122.255.25441.122.255.25532,766
24741.123.0.0/1741.123.0.1 to 41.123.127.25441.123.127.25532,766
24841.123.128.0/1741.123.128.1 to 41.123.255.25441.123.255.25532,766
24941.124.0.0/1741.124.0.1 to 41.124.127.25441.124.127.25532,766
25041.124.128.0/1741.124.128.1 to 41.124.255.25441.124.255.25532,766
25141.125.0.0/1741.125.0.1 to 41.125.127.25441.125.127.25532,766
25241.125.128.0/1741.125.128.1 to 41.125.255.25441.125.255.25532,766
25341.126.0.0/1741.126.0.1 to 41.126.127.25441.126.127.25532,766
25441.126.128.0/1741.126.128.1 to 41.126.255.25441.126.255.25532,766
25541.127.0.0/1741.127.0.1 to 41.127.127.25441.127.127.25532,766
25641.127.128.0/1741.127.128.1 to 41.127.255.25441.127.255.25532,766

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.