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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.

Network61.64.0.0/10
Usable hosts4,194,302
Subnet mask255.192.0.0
Addresses4,194,304
Network address
61.64.0.0
Broadcast address
61.127.255.255
First usable
61.64.0.1
Last usable
61.127.255.254
Usable hosts
4,194,302 (4,194,304 less the network and broadcast addresses)
Subnet mask
255.192.0.0
Wildcard mask
0.63.255.255 (Cisco ACLs, OSPF)
Prefix length
/10
Type
Public public
Old class
A (default /8)
As numbers
Hex 3D400000 · Integer 1027604480 to 1031798783
Reverse DNS zones
64.61.in-addr.arpa
65.61.in-addr.arpa
66.61.in-addr.arpa
67.61.in-addr.arpa
68.61.in-addr.arpa
69.61.in-addr.arpa
70.61.in-addr.arpa
71.61.in-addr.arpa
72.61.in-addr.arpa
73.61.in-addr.arpa
74.61.in-addr.arpa
75.61.in-addr.arpa
76.61.in-addr.arpa
77.61.in-addr.arpa
78.61.in-addr.arpa
79.61.in-addr.arpa
and 48 more
/10 is not on a 8-bit boundary, so it takes 64 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address00111101.01000000.00000000.0000000061.64.0.0
Subnet mask11111111.11000000.00000000.00000000255.192.0.0
Network00111101.01000000.00000000.0000000061.64.0.0
Broadcast00111101.01111111.11111111.1111111161.127.255.255
Split into smaller subnets/18
/11 (2)/12 (4)/13 (8)/14 (16)/15 (32)/16 (64)/17 (128)/18 (256)/19 (512)/20 (1,024)/21 (2,048)/22 (4,096)

61.64.0.0/10 makes 256 subnets of /18.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
161.64.0.0/1861.64.0.1 to 61.64.63.25461.64.63.25516,382
261.64.64.0/1861.64.64.1 to 61.64.127.25461.64.127.25516,382
361.64.128.0/1861.64.128.1 to 61.64.191.25461.64.191.25516,382
461.64.192.0/1861.64.192.1 to 61.64.255.25461.64.255.25516,382
561.65.0.0/1861.65.0.1 to 61.65.63.25461.65.63.25516,382
661.65.64.0/1861.65.64.1 to 61.65.127.25461.65.127.25516,382
761.65.128.0/1861.65.128.1 to 61.65.191.25461.65.191.25516,382
861.65.192.0/1861.65.192.1 to 61.65.255.25461.65.255.25516,382
961.66.0.0/1861.66.0.1 to 61.66.63.25461.66.63.25516,382
1061.66.64.0/1861.66.64.1 to 61.66.127.25461.66.127.25516,382
1161.66.128.0/1861.66.128.1 to 61.66.191.25461.66.191.25516,382
1261.66.192.0/1861.66.192.1 to 61.66.255.25461.66.255.25516,382
1361.67.0.0/1861.67.0.1 to 61.67.63.25461.67.63.25516,382
1461.67.64.0/1861.67.64.1 to 61.67.127.25461.67.127.25516,382
1561.67.128.0/1861.67.128.1 to 61.67.191.25461.67.191.25516,382
1661.67.192.0/1861.67.192.1 to 61.67.255.25461.67.255.25516,382
1761.68.0.0/1861.68.0.1 to 61.68.63.25461.68.63.25516,382
1861.68.64.0/1861.68.64.1 to 61.68.127.25461.68.127.25516,382
1961.68.128.0/1861.68.128.1 to 61.68.191.25461.68.191.25516,382
2061.68.192.0/1861.68.192.1 to 61.68.255.25461.68.255.25516,382
2161.69.0.0/1861.69.0.1 to 61.69.63.25461.69.63.25516,382
2261.69.64.0/1861.69.64.1 to 61.69.127.25461.69.127.25516,382
2361.69.128.0/1861.69.128.1 to 61.69.191.25461.69.191.25516,382
2461.69.192.0/1861.69.192.1 to 61.69.255.25461.69.255.25516,382
2561.70.0.0/1861.70.0.1 to 61.70.63.25461.70.63.25516,382
2661.70.64.0/1861.70.64.1 to 61.70.127.25461.70.127.25516,382
2761.70.128.0/1861.70.128.1 to 61.70.191.25461.70.191.25516,382
2861.70.192.0/1861.70.192.1 to 61.70.255.25461.70.255.25516,382
2961.71.0.0/1861.71.0.1 to 61.71.63.25461.71.63.25516,382
3061.71.64.0/1861.71.64.1 to 61.71.127.25461.71.127.25516,382
3161.71.128.0/1861.71.128.1 to 61.71.191.25461.71.191.25516,382
3261.71.192.0/1861.71.192.1 to 61.71.255.25461.71.255.25516,382
3361.72.0.0/1861.72.0.1 to 61.72.63.25461.72.63.25516,382
3461.72.64.0/1861.72.64.1 to 61.72.127.25461.72.127.25516,382
3561.72.128.0/1861.72.128.1 to 61.72.191.25461.72.191.25516,382
3661.72.192.0/1861.72.192.1 to 61.72.255.25461.72.255.25516,382
3761.73.0.0/1861.73.0.1 to 61.73.63.25461.73.63.25516,382
3861.73.64.0/1861.73.64.1 to 61.73.127.25461.73.127.25516,382
3961.73.128.0/1861.73.128.1 to 61.73.191.25461.73.191.25516,382
4061.73.192.0/1861.73.192.1 to 61.73.255.25461.73.255.25516,382
4161.74.0.0/1861.74.0.1 to 61.74.63.25461.74.63.25516,382
4261.74.64.0/1861.74.64.1 to 61.74.127.25461.74.127.25516,382
4361.74.128.0/1861.74.128.1 to 61.74.191.25461.74.191.25516,382
4461.74.192.0/1861.74.192.1 to 61.74.255.25461.74.255.25516,382
4561.75.0.0/1861.75.0.1 to 61.75.63.25461.75.63.25516,382
4661.75.64.0/1861.75.64.1 to 61.75.127.25461.75.127.25516,382
4761.75.128.0/1861.75.128.1 to 61.75.191.25461.75.191.25516,382
4861.75.192.0/1861.75.192.1 to 61.75.255.25461.75.255.25516,382
4961.76.0.0/1861.76.0.1 to 61.76.63.25461.76.63.25516,382
5061.76.64.0/1861.76.64.1 to 61.76.127.25461.76.127.25516,382
5161.76.128.0/1861.76.128.1 to 61.76.191.25461.76.191.25516,382
5261.76.192.0/1861.76.192.1 to 61.76.255.25461.76.255.25516,382
5361.77.0.0/1861.77.0.1 to 61.77.63.25461.77.63.25516,382
5461.77.64.0/1861.77.64.1 to 61.77.127.25461.77.127.25516,382
5561.77.128.0/1861.77.128.1 to 61.77.191.25461.77.191.25516,382
5661.77.192.0/1861.77.192.1 to 61.77.255.25461.77.255.25516,382
5761.78.0.0/1861.78.0.1 to 61.78.63.25461.78.63.25516,382
5861.78.64.0/1861.78.64.1 to 61.78.127.25461.78.127.25516,382
5961.78.128.0/1861.78.128.1 to 61.78.191.25461.78.191.25516,382
6061.78.192.0/1861.78.192.1 to 61.78.255.25461.78.255.25516,382
6161.79.0.0/1861.79.0.1 to 61.79.63.25461.79.63.25516,382
6261.79.64.0/1861.79.64.1 to 61.79.127.25461.79.127.25516,382
6361.79.128.0/1861.79.128.1 to 61.79.191.25461.79.191.25516,382
6461.79.192.0/1861.79.192.1 to 61.79.255.25461.79.255.25516,382
6561.80.0.0/1861.80.0.1 to 61.80.63.25461.80.63.25516,382
6661.80.64.0/1861.80.64.1 to 61.80.127.25461.80.127.25516,382
6761.80.128.0/1861.80.128.1 to 61.80.191.25461.80.191.25516,382
6861.80.192.0/1861.80.192.1 to 61.80.255.25461.80.255.25516,382
6961.81.0.0/1861.81.0.1 to 61.81.63.25461.81.63.25516,382
7061.81.64.0/1861.81.64.1 to 61.81.127.25461.81.127.25516,382
7161.81.128.0/1861.81.128.1 to 61.81.191.25461.81.191.25516,382
7261.81.192.0/1861.81.192.1 to 61.81.255.25461.81.255.25516,382
7361.82.0.0/1861.82.0.1 to 61.82.63.25461.82.63.25516,382
7461.82.64.0/1861.82.64.1 to 61.82.127.25461.82.127.25516,382
7561.82.128.0/1861.82.128.1 to 61.82.191.25461.82.191.25516,382
7661.82.192.0/1861.82.192.1 to 61.82.255.25461.82.255.25516,382
7761.83.0.0/1861.83.0.1 to 61.83.63.25461.83.63.25516,382
7861.83.64.0/1861.83.64.1 to 61.83.127.25461.83.127.25516,382
7961.83.128.0/1861.83.128.1 to 61.83.191.25461.83.191.25516,382
8061.83.192.0/1861.83.192.1 to 61.83.255.25461.83.255.25516,382
8161.84.0.0/1861.84.0.1 to 61.84.63.25461.84.63.25516,382
8261.84.64.0/1861.84.64.1 to 61.84.127.25461.84.127.25516,382
8361.84.128.0/1861.84.128.1 to 61.84.191.25461.84.191.25516,382
8461.84.192.0/1861.84.192.1 to 61.84.255.25461.84.255.25516,382
8561.85.0.0/1861.85.0.1 to 61.85.63.25461.85.63.25516,382
8661.85.64.0/1861.85.64.1 to 61.85.127.25461.85.127.25516,382
8761.85.128.0/1861.85.128.1 to 61.85.191.25461.85.191.25516,382
8861.85.192.0/1861.85.192.1 to 61.85.255.25461.85.255.25516,382
8961.86.0.0/1861.86.0.1 to 61.86.63.25461.86.63.25516,382
9061.86.64.0/1861.86.64.1 to 61.86.127.25461.86.127.25516,382
9161.86.128.0/1861.86.128.1 to 61.86.191.25461.86.191.25516,382
9261.86.192.0/1861.86.192.1 to 61.86.255.25461.86.255.25516,382
9361.87.0.0/1861.87.0.1 to 61.87.63.25461.87.63.25516,382
9461.87.64.0/1861.87.64.1 to 61.87.127.25461.87.127.25516,382
9561.87.128.0/1861.87.128.1 to 61.87.191.25461.87.191.25516,382
9661.87.192.0/1861.87.192.1 to 61.87.255.25461.87.255.25516,382
9761.88.0.0/1861.88.0.1 to 61.88.63.25461.88.63.25516,382
9861.88.64.0/1861.88.64.1 to 61.88.127.25461.88.127.25516,382
9961.88.128.0/1861.88.128.1 to 61.88.191.25461.88.191.25516,382
10061.88.192.0/1861.88.192.1 to 61.88.255.25461.88.255.25516,382
10161.89.0.0/1861.89.0.1 to 61.89.63.25461.89.63.25516,382
10261.89.64.0/1861.89.64.1 to 61.89.127.25461.89.127.25516,382
10361.89.128.0/1861.89.128.1 to 61.89.191.25461.89.191.25516,382
10461.89.192.0/1861.89.192.1 to 61.89.255.25461.89.255.25516,382
10561.90.0.0/1861.90.0.1 to 61.90.63.25461.90.63.25516,382
10661.90.64.0/1861.90.64.1 to 61.90.127.25461.90.127.25516,382
10761.90.128.0/1861.90.128.1 to 61.90.191.25461.90.191.25516,382
10861.90.192.0/1861.90.192.1 to 61.90.255.25461.90.255.25516,382
10961.91.0.0/1861.91.0.1 to 61.91.63.25461.91.63.25516,382
11061.91.64.0/1861.91.64.1 to 61.91.127.25461.91.127.25516,382
11161.91.128.0/1861.91.128.1 to 61.91.191.25461.91.191.25516,382
11261.91.192.0/1861.91.192.1 to 61.91.255.25461.91.255.25516,382
11361.92.0.0/1861.92.0.1 to 61.92.63.25461.92.63.25516,382
11461.92.64.0/1861.92.64.1 to 61.92.127.25461.92.127.25516,382
11561.92.128.0/1861.92.128.1 to 61.92.191.25461.92.191.25516,382
11661.92.192.0/1861.92.192.1 to 61.92.255.25461.92.255.25516,382
11761.93.0.0/1861.93.0.1 to 61.93.63.25461.93.63.25516,382
11861.93.64.0/1861.93.64.1 to 61.93.127.25461.93.127.25516,382
11961.93.128.0/1861.93.128.1 to 61.93.191.25461.93.191.25516,382
12061.93.192.0/1861.93.192.1 to 61.93.255.25461.93.255.25516,382
12161.94.0.0/1861.94.0.1 to 61.94.63.25461.94.63.25516,382
12261.94.64.0/1861.94.64.1 to 61.94.127.25461.94.127.25516,382
12361.94.128.0/1861.94.128.1 to 61.94.191.25461.94.191.25516,382
12461.94.192.0/1861.94.192.1 to 61.94.255.25461.94.255.25516,382
12561.95.0.0/1861.95.0.1 to 61.95.63.25461.95.63.25516,382
12661.95.64.0/1861.95.64.1 to 61.95.127.25461.95.127.25516,382
12761.95.128.0/1861.95.128.1 to 61.95.191.25461.95.191.25516,382
12861.95.192.0/1861.95.192.1 to 61.95.255.25461.95.255.25516,382
12961.96.0.0/1861.96.0.1 to 61.96.63.25461.96.63.25516,382
13061.96.64.0/1861.96.64.1 to 61.96.127.25461.96.127.25516,382
13161.96.128.0/1861.96.128.1 to 61.96.191.25461.96.191.25516,382
13261.96.192.0/1861.96.192.1 to 61.96.255.25461.96.255.25516,382
13361.97.0.0/1861.97.0.1 to 61.97.63.25461.97.63.25516,382
13461.97.64.0/1861.97.64.1 to 61.97.127.25461.97.127.25516,382
13561.97.128.0/1861.97.128.1 to 61.97.191.25461.97.191.25516,382
13661.97.192.0/1861.97.192.1 to 61.97.255.25461.97.255.25516,382
13761.98.0.0/1861.98.0.1 to 61.98.63.25461.98.63.25516,382
13861.98.64.0/1861.98.64.1 to 61.98.127.25461.98.127.25516,382
13961.98.128.0/1861.98.128.1 to 61.98.191.25461.98.191.25516,382
14061.98.192.0/1861.98.192.1 to 61.98.255.25461.98.255.25516,382
14161.99.0.0/1861.99.0.1 to 61.99.63.25461.99.63.25516,382
14261.99.64.0/1861.99.64.1 to 61.99.127.25461.99.127.25516,382
14361.99.128.0/1861.99.128.1 to 61.99.191.25461.99.191.25516,382
14461.99.192.0/1861.99.192.1 to 61.99.255.25461.99.255.25516,382
14561.100.0.0/1861.100.0.1 to 61.100.63.25461.100.63.25516,382
14661.100.64.0/1861.100.64.1 to 61.100.127.25461.100.127.25516,382
14761.100.128.0/1861.100.128.1 to 61.100.191.25461.100.191.25516,382
14861.100.192.0/1861.100.192.1 to 61.100.255.25461.100.255.25516,382
14961.101.0.0/1861.101.0.1 to 61.101.63.25461.101.63.25516,382
15061.101.64.0/1861.101.64.1 to 61.101.127.25461.101.127.25516,382
15161.101.128.0/1861.101.128.1 to 61.101.191.25461.101.191.25516,382
15261.101.192.0/1861.101.192.1 to 61.101.255.25461.101.255.25516,382
15361.102.0.0/1861.102.0.1 to 61.102.63.25461.102.63.25516,382
15461.102.64.0/1861.102.64.1 to 61.102.127.25461.102.127.25516,382
15561.102.128.0/1861.102.128.1 to 61.102.191.25461.102.191.25516,382
15661.102.192.0/1861.102.192.1 to 61.102.255.25461.102.255.25516,382
15761.103.0.0/1861.103.0.1 to 61.103.63.25461.103.63.25516,382
15861.103.64.0/1861.103.64.1 to 61.103.127.25461.103.127.25516,382
15961.103.128.0/1861.103.128.1 to 61.103.191.25461.103.191.25516,382
16061.103.192.0/1861.103.192.1 to 61.103.255.25461.103.255.25516,382
16161.104.0.0/1861.104.0.1 to 61.104.63.25461.104.63.25516,382
16261.104.64.0/1861.104.64.1 to 61.104.127.25461.104.127.25516,382
16361.104.128.0/1861.104.128.1 to 61.104.191.25461.104.191.25516,382
16461.104.192.0/1861.104.192.1 to 61.104.255.25461.104.255.25516,382
16561.105.0.0/1861.105.0.1 to 61.105.63.25461.105.63.25516,382
16661.105.64.0/1861.105.64.1 to 61.105.127.25461.105.127.25516,382
16761.105.128.0/1861.105.128.1 to 61.105.191.25461.105.191.25516,382
16861.105.192.0/1861.105.192.1 to 61.105.255.25461.105.255.25516,382
16961.106.0.0/1861.106.0.1 to 61.106.63.25461.106.63.25516,382
17061.106.64.0/1861.106.64.1 to 61.106.127.25461.106.127.25516,382
17161.106.128.0/1861.106.128.1 to 61.106.191.25461.106.191.25516,382
17261.106.192.0/1861.106.192.1 to 61.106.255.25461.106.255.25516,382
17361.107.0.0/1861.107.0.1 to 61.107.63.25461.107.63.25516,382
17461.107.64.0/1861.107.64.1 to 61.107.127.25461.107.127.25516,382
17561.107.128.0/1861.107.128.1 to 61.107.191.25461.107.191.25516,382
17661.107.192.0/1861.107.192.1 to 61.107.255.25461.107.255.25516,382
17761.108.0.0/1861.108.0.1 to 61.108.63.25461.108.63.25516,382
17861.108.64.0/1861.108.64.1 to 61.108.127.25461.108.127.25516,382
17961.108.128.0/1861.108.128.1 to 61.108.191.25461.108.191.25516,382
18061.108.192.0/1861.108.192.1 to 61.108.255.25461.108.255.25516,382
18161.109.0.0/1861.109.0.1 to 61.109.63.25461.109.63.25516,382
18261.109.64.0/1861.109.64.1 to 61.109.127.25461.109.127.25516,382
18361.109.128.0/1861.109.128.1 to 61.109.191.25461.109.191.25516,382
18461.109.192.0/1861.109.192.1 to 61.109.255.25461.109.255.25516,382
18561.110.0.0/1861.110.0.1 to 61.110.63.25461.110.63.25516,382
18661.110.64.0/1861.110.64.1 to 61.110.127.25461.110.127.25516,382
18761.110.128.0/1861.110.128.1 to 61.110.191.25461.110.191.25516,382
18861.110.192.0/1861.110.192.1 to 61.110.255.25461.110.255.25516,382
18961.111.0.0/1861.111.0.1 to 61.111.63.25461.111.63.25516,382
19061.111.64.0/1861.111.64.1 to 61.111.127.25461.111.127.25516,382
19161.111.128.0/1861.111.128.1 to 61.111.191.25461.111.191.25516,382
19261.111.192.0/1861.111.192.1 to 61.111.255.25461.111.255.25516,382
19361.112.0.0/1861.112.0.1 to 61.112.63.25461.112.63.25516,382
19461.112.64.0/1861.112.64.1 to 61.112.127.25461.112.127.25516,382
19561.112.128.0/1861.112.128.1 to 61.112.191.25461.112.191.25516,382
19661.112.192.0/1861.112.192.1 to 61.112.255.25461.112.255.25516,382
19761.113.0.0/1861.113.0.1 to 61.113.63.25461.113.63.25516,382
19861.113.64.0/1861.113.64.1 to 61.113.127.25461.113.127.25516,382
19961.113.128.0/1861.113.128.1 to 61.113.191.25461.113.191.25516,382
20061.113.192.0/1861.113.192.1 to 61.113.255.25461.113.255.25516,382
20161.114.0.0/1861.114.0.1 to 61.114.63.25461.114.63.25516,382
20261.114.64.0/1861.114.64.1 to 61.114.127.25461.114.127.25516,382
20361.114.128.0/1861.114.128.1 to 61.114.191.25461.114.191.25516,382
20461.114.192.0/1861.114.192.1 to 61.114.255.25461.114.255.25516,382
20561.115.0.0/1861.115.0.1 to 61.115.63.25461.115.63.25516,382
20661.115.64.0/1861.115.64.1 to 61.115.127.25461.115.127.25516,382
20761.115.128.0/1861.115.128.1 to 61.115.191.25461.115.191.25516,382
20861.115.192.0/1861.115.192.1 to 61.115.255.25461.115.255.25516,382
20961.116.0.0/1861.116.0.1 to 61.116.63.25461.116.63.25516,382
21061.116.64.0/1861.116.64.1 to 61.116.127.25461.116.127.25516,382
21161.116.128.0/1861.116.128.1 to 61.116.191.25461.116.191.25516,382
21261.116.192.0/1861.116.192.1 to 61.116.255.25461.116.255.25516,382
21361.117.0.0/1861.117.0.1 to 61.117.63.25461.117.63.25516,382
21461.117.64.0/1861.117.64.1 to 61.117.127.25461.117.127.25516,382
21561.117.128.0/1861.117.128.1 to 61.117.191.25461.117.191.25516,382
21661.117.192.0/1861.117.192.1 to 61.117.255.25461.117.255.25516,382
21761.118.0.0/1861.118.0.1 to 61.118.63.25461.118.63.25516,382
21861.118.64.0/1861.118.64.1 to 61.118.127.25461.118.127.25516,382
21961.118.128.0/1861.118.128.1 to 61.118.191.25461.118.191.25516,382
22061.118.192.0/1861.118.192.1 to 61.118.255.25461.118.255.25516,382
22161.119.0.0/1861.119.0.1 to 61.119.63.25461.119.63.25516,382
22261.119.64.0/1861.119.64.1 to 61.119.127.25461.119.127.25516,382
22361.119.128.0/1861.119.128.1 to 61.119.191.25461.119.191.25516,382
22461.119.192.0/1861.119.192.1 to 61.119.255.25461.119.255.25516,382
22561.120.0.0/1861.120.0.1 to 61.120.63.25461.120.63.25516,382
22661.120.64.0/1861.120.64.1 to 61.120.127.25461.120.127.25516,382
22761.120.128.0/1861.120.128.1 to 61.120.191.25461.120.191.25516,382
22861.120.192.0/1861.120.192.1 to 61.120.255.25461.120.255.25516,382
22961.121.0.0/1861.121.0.1 to 61.121.63.25461.121.63.25516,382
23061.121.64.0/1861.121.64.1 to 61.121.127.25461.121.127.25516,382
23161.121.128.0/1861.121.128.1 to 61.121.191.25461.121.191.25516,382
23261.121.192.0/1861.121.192.1 to 61.121.255.25461.121.255.25516,382
23361.122.0.0/1861.122.0.1 to 61.122.63.25461.122.63.25516,382
23461.122.64.0/1861.122.64.1 to 61.122.127.25461.122.127.25516,382
23561.122.128.0/1861.122.128.1 to 61.122.191.25461.122.191.25516,382
23661.122.192.0/1861.122.192.1 to 61.122.255.25461.122.255.25516,382
23761.123.0.0/1861.123.0.1 to 61.123.63.25461.123.63.25516,382
23861.123.64.0/1861.123.64.1 to 61.123.127.25461.123.127.25516,382
23961.123.128.0/1861.123.128.1 to 61.123.191.25461.123.191.25516,382
24061.123.192.0/1861.123.192.1 to 61.123.255.25461.123.255.25516,382
24161.124.0.0/1861.124.0.1 to 61.124.63.25461.124.63.25516,382
24261.124.64.0/1861.124.64.1 to 61.124.127.25461.124.127.25516,382
24361.124.128.0/1861.124.128.1 to 61.124.191.25461.124.191.25516,382
24461.124.192.0/1861.124.192.1 to 61.124.255.25461.124.255.25516,382
24561.125.0.0/1861.125.0.1 to 61.125.63.25461.125.63.25516,382
24661.125.64.0/1861.125.64.1 to 61.125.127.25461.125.127.25516,382
24761.125.128.0/1861.125.128.1 to 61.125.191.25461.125.191.25516,382
24861.125.192.0/1861.125.192.1 to 61.125.255.25461.125.255.25516,382
24961.126.0.0/1861.126.0.1 to 61.126.63.25461.126.63.25516,382
25061.126.64.0/1861.126.64.1 to 61.126.127.25461.126.127.25516,382
25161.126.128.0/1861.126.128.1 to 61.126.191.25461.126.191.25516,382
25261.126.192.0/1861.126.192.1 to 61.126.255.25461.126.255.25516,382
25361.127.0.0/1861.127.0.1 to 61.127.63.25461.127.63.25516,382
25461.127.64.0/1861.127.64.1 to 61.127.127.25461.127.127.25516,382
25561.127.128.0/1861.127.128.1 to 61.127.191.25461.127.191.25516,382
25661.127.192.0/1861.127.192.1 to 61.127.255.25461.127.255.25516,382

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.