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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.

Network39.64.0.0/10
Usable hosts4,194,302
Subnet mask255.192.0.0
Addresses4,194,304
Network address
39.64.0.0
Broadcast address
39.127.255.255
First usable
39.64.0.1
Last usable
39.127.255.254
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 27400000 · Integer 658505728 to 662700031
Reverse DNS zones
64.39.in-addr.arpa
65.39.in-addr.arpa
66.39.in-addr.arpa
67.39.in-addr.arpa
68.39.in-addr.arpa
69.39.in-addr.arpa
70.39.in-addr.arpa
71.39.in-addr.arpa
72.39.in-addr.arpa
73.39.in-addr.arpa
74.39.in-addr.arpa
75.39.in-addr.arpa
76.39.in-addr.arpa
77.39.in-addr.arpa
78.39.in-addr.arpa
79.39.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
Address00100111.01000000.00000000.0000000039.64.0.0
Subnet mask11111111.11000000.00000000.00000000255.192.0.0
Network00100111.01000000.00000000.0000000039.64.0.0
Broadcast00100111.01111111.11111111.1111111139.127.255.255
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)

39.64.0.0/10 makes 256 subnets of /18.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
139.64.0.0/1839.64.0.1 to 39.64.63.25439.64.63.25516,382
239.64.64.0/1839.64.64.1 to 39.64.127.25439.64.127.25516,382
339.64.128.0/1839.64.128.1 to 39.64.191.25439.64.191.25516,382
439.64.192.0/1839.64.192.1 to 39.64.255.25439.64.255.25516,382
539.65.0.0/1839.65.0.1 to 39.65.63.25439.65.63.25516,382
639.65.64.0/1839.65.64.1 to 39.65.127.25439.65.127.25516,382
739.65.128.0/1839.65.128.1 to 39.65.191.25439.65.191.25516,382
839.65.192.0/1839.65.192.1 to 39.65.255.25439.65.255.25516,382
939.66.0.0/1839.66.0.1 to 39.66.63.25439.66.63.25516,382
1039.66.64.0/1839.66.64.1 to 39.66.127.25439.66.127.25516,382
1139.66.128.0/1839.66.128.1 to 39.66.191.25439.66.191.25516,382
1239.66.192.0/1839.66.192.1 to 39.66.255.25439.66.255.25516,382
1339.67.0.0/1839.67.0.1 to 39.67.63.25439.67.63.25516,382
1439.67.64.0/1839.67.64.1 to 39.67.127.25439.67.127.25516,382
1539.67.128.0/1839.67.128.1 to 39.67.191.25439.67.191.25516,382
1639.67.192.0/1839.67.192.1 to 39.67.255.25439.67.255.25516,382
1739.68.0.0/1839.68.0.1 to 39.68.63.25439.68.63.25516,382
1839.68.64.0/1839.68.64.1 to 39.68.127.25439.68.127.25516,382
1939.68.128.0/1839.68.128.1 to 39.68.191.25439.68.191.25516,382
2039.68.192.0/1839.68.192.1 to 39.68.255.25439.68.255.25516,382
2139.69.0.0/1839.69.0.1 to 39.69.63.25439.69.63.25516,382
2239.69.64.0/1839.69.64.1 to 39.69.127.25439.69.127.25516,382
2339.69.128.0/1839.69.128.1 to 39.69.191.25439.69.191.25516,382
2439.69.192.0/1839.69.192.1 to 39.69.255.25439.69.255.25516,382
2539.70.0.0/1839.70.0.1 to 39.70.63.25439.70.63.25516,382
2639.70.64.0/1839.70.64.1 to 39.70.127.25439.70.127.25516,382
2739.70.128.0/1839.70.128.1 to 39.70.191.25439.70.191.25516,382
2839.70.192.0/1839.70.192.1 to 39.70.255.25439.70.255.25516,382
2939.71.0.0/1839.71.0.1 to 39.71.63.25439.71.63.25516,382
3039.71.64.0/1839.71.64.1 to 39.71.127.25439.71.127.25516,382
3139.71.128.0/1839.71.128.1 to 39.71.191.25439.71.191.25516,382
3239.71.192.0/1839.71.192.1 to 39.71.255.25439.71.255.25516,382
3339.72.0.0/1839.72.0.1 to 39.72.63.25439.72.63.25516,382
3439.72.64.0/1839.72.64.1 to 39.72.127.25439.72.127.25516,382
3539.72.128.0/1839.72.128.1 to 39.72.191.25439.72.191.25516,382
3639.72.192.0/1839.72.192.1 to 39.72.255.25439.72.255.25516,382
3739.73.0.0/1839.73.0.1 to 39.73.63.25439.73.63.25516,382
3839.73.64.0/1839.73.64.1 to 39.73.127.25439.73.127.25516,382
3939.73.128.0/1839.73.128.1 to 39.73.191.25439.73.191.25516,382
4039.73.192.0/1839.73.192.1 to 39.73.255.25439.73.255.25516,382
4139.74.0.0/1839.74.0.1 to 39.74.63.25439.74.63.25516,382
4239.74.64.0/1839.74.64.1 to 39.74.127.25439.74.127.25516,382
4339.74.128.0/1839.74.128.1 to 39.74.191.25439.74.191.25516,382
4439.74.192.0/1839.74.192.1 to 39.74.255.25439.74.255.25516,382
4539.75.0.0/1839.75.0.1 to 39.75.63.25439.75.63.25516,382
4639.75.64.0/1839.75.64.1 to 39.75.127.25439.75.127.25516,382
4739.75.128.0/1839.75.128.1 to 39.75.191.25439.75.191.25516,382
4839.75.192.0/1839.75.192.1 to 39.75.255.25439.75.255.25516,382
4939.76.0.0/1839.76.0.1 to 39.76.63.25439.76.63.25516,382
5039.76.64.0/1839.76.64.1 to 39.76.127.25439.76.127.25516,382
5139.76.128.0/1839.76.128.1 to 39.76.191.25439.76.191.25516,382
5239.76.192.0/1839.76.192.1 to 39.76.255.25439.76.255.25516,382
5339.77.0.0/1839.77.0.1 to 39.77.63.25439.77.63.25516,382
5439.77.64.0/1839.77.64.1 to 39.77.127.25439.77.127.25516,382
5539.77.128.0/1839.77.128.1 to 39.77.191.25439.77.191.25516,382
5639.77.192.0/1839.77.192.1 to 39.77.255.25439.77.255.25516,382
5739.78.0.0/1839.78.0.1 to 39.78.63.25439.78.63.25516,382
5839.78.64.0/1839.78.64.1 to 39.78.127.25439.78.127.25516,382
5939.78.128.0/1839.78.128.1 to 39.78.191.25439.78.191.25516,382
6039.78.192.0/1839.78.192.1 to 39.78.255.25439.78.255.25516,382
6139.79.0.0/1839.79.0.1 to 39.79.63.25439.79.63.25516,382
6239.79.64.0/1839.79.64.1 to 39.79.127.25439.79.127.25516,382
6339.79.128.0/1839.79.128.1 to 39.79.191.25439.79.191.25516,382
6439.79.192.0/1839.79.192.1 to 39.79.255.25439.79.255.25516,382
6539.80.0.0/1839.80.0.1 to 39.80.63.25439.80.63.25516,382
6639.80.64.0/1839.80.64.1 to 39.80.127.25439.80.127.25516,382
6739.80.128.0/1839.80.128.1 to 39.80.191.25439.80.191.25516,382
6839.80.192.0/1839.80.192.1 to 39.80.255.25439.80.255.25516,382
6939.81.0.0/1839.81.0.1 to 39.81.63.25439.81.63.25516,382
7039.81.64.0/1839.81.64.1 to 39.81.127.25439.81.127.25516,382
7139.81.128.0/1839.81.128.1 to 39.81.191.25439.81.191.25516,382
7239.81.192.0/1839.81.192.1 to 39.81.255.25439.81.255.25516,382
7339.82.0.0/1839.82.0.1 to 39.82.63.25439.82.63.25516,382
7439.82.64.0/1839.82.64.1 to 39.82.127.25439.82.127.25516,382
7539.82.128.0/1839.82.128.1 to 39.82.191.25439.82.191.25516,382
7639.82.192.0/1839.82.192.1 to 39.82.255.25439.82.255.25516,382
7739.83.0.0/1839.83.0.1 to 39.83.63.25439.83.63.25516,382
7839.83.64.0/1839.83.64.1 to 39.83.127.25439.83.127.25516,382
7939.83.128.0/1839.83.128.1 to 39.83.191.25439.83.191.25516,382
8039.83.192.0/1839.83.192.1 to 39.83.255.25439.83.255.25516,382
8139.84.0.0/1839.84.0.1 to 39.84.63.25439.84.63.25516,382
8239.84.64.0/1839.84.64.1 to 39.84.127.25439.84.127.25516,382
8339.84.128.0/1839.84.128.1 to 39.84.191.25439.84.191.25516,382
8439.84.192.0/1839.84.192.1 to 39.84.255.25439.84.255.25516,382
8539.85.0.0/1839.85.0.1 to 39.85.63.25439.85.63.25516,382
8639.85.64.0/1839.85.64.1 to 39.85.127.25439.85.127.25516,382
8739.85.128.0/1839.85.128.1 to 39.85.191.25439.85.191.25516,382
8839.85.192.0/1839.85.192.1 to 39.85.255.25439.85.255.25516,382
8939.86.0.0/1839.86.0.1 to 39.86.63.25439.86.63.25516,382
9039.86.64.0/1839.86.64.1 to 39.86.127.25439.86.127.25516,382
9139.86.128.0/1839.86.128.1 to 39.86.191.25439.86.191.25516,382
9239.86.192.0/1839.86.192.1 to 39.86.255.25439.86.255.25516,382
9339.87.0.0/1839.87.0.1 to 39.87.63.25439.87.63.25516,382
9439.87.64.0/1839.87.64.1 to 39.87.127.25439.87.127.25516,382
9539.87.128.0/1839.87.128.1 to 39.87.191.25439.87.191.25516,382
9639.87.192.0/1839.87.192.1 to 39.87.255.25439.87.255.25516,382
9739.88.0.0/1839.88.0.1 to 39.88.63.25439.88.63.25516,382
9839.88.64.0/1839.88.64.1 to 39.88.127.25439.88.127.25516,382
9939.88.128.0/1839.88.128.1 to 39.88.191.25439.88.191.25516,382
10039.88.192.0/1839.88.192.1 to 39.88.255.25439.88.255.25516,382
10139.89.0.0/1839.89.0.1 to 39.89.63.25439.89.63.25516,382
10239.89.64.0/1839.89.64.1 to 39.89.127.25439.89.127.25516,382
10339.89.128.0/1839.89.128.1 to 39.89.191.25439.89.191.25516,382
10439.89.192.0/1839.89.192.1 to 39.89.255.25439.89.255.25516,382
10539.90.0.0/1839.90.0.1 to 39.90.63.25439.90.63.25516,382
10639.90.64.0/1839.90.64.1 to 39.90.127.25439.90.127.25516,382
10739.90.128.0/1839.90.128.1 to 39.90.191.25439.90.191.25516,382
10839.90.192.0/1839.90.192.1 to 39.90.255.25439.90.255.25516,382
10939.91.0.0/1839.91.0.1 to 39.91.63.25439.91.63.25516,382
11039.91.64.0/1839.91.64.1 to 39.91.127.25439.91.127.25516,382
11139.91.128.0/1839.91.128.1 to 39.91.191.25439.91.191.25516,382
11239.91.192.0/1839.91.192.1 to 39.91.255.25439.91.255.25516,382
11339.92.0.0/1839.92.0.1 to 39.92.63.25439.92.63.25516,382
11439.92.64.0/1839.92.64.1 to 39.92.127.25439.92.127.25516,382
11539.92.128.0/1839.92.128.1 to 39.92.191.25439.92.191.25516,382
11639.92.192.0/1839.92.192.1 to 39.92.255.25439.92.255.25516,382
11739.93.0.0/1839.93.0.1 to 39.93.63.25439.93.63.25516,382
11839.93.64.0/1839.93.64.1 to 39.93.127.25439.93.127.25516,382
11939.93.128.0/1839.93.128.1 to 39.93.191.25439.93.191.25516,382
12039.93.192.0/1839.93.192.1 to 39.93.255.25439.93.255.25516,382
12139.94.0.0/1839.94.0.1 to 39.94.63.25439.94.63.25516,382
12239.94.64.0/1839.94.64.1 to 39.94.127.25439.94.127.25516,382
12339.94.128.0/1839.94.128.1 to 39.94.191.25439.94.191.25516,382
12439.94.192.0/1839.94.192.1 to 39.94.255.25439.94.255.25516,382
12539.95.0.0/1839.95.0.1 to 39.95.63.25439.95.63.25516,382
12639.95.64.0/1839.95.64.1 to 39.95.127.25439.95.127.25516,382
12739.95.128.0/1839.95.128.1 to 39.95.191.25439.95.191.25516,382
12839.95.192.0/1839.95.192.1 to 39.95.255.25439.95.255.25516,382
12939.96.0.0/1839.96.0.1 to 39.96.63.25439.96.63.25516,382
13039.96.64.0/1839.96.64.1 to 39.96.127.25439.96.127.25516,382
13139.96.128.0/1839.96.128.1 to 39.96.191.25439.96.191.25516,382
13239.96.192.0/1839.96.192.1 to 39.96.255.25439.96.255.25516,382
13339.97.0.0/1839.97.0.1 to 39.97.63.25439.97.63.25516,382
13439.97.64.0/1839.97.64.1 to 39.97.127.25439.97.127.25516,382
13539.97.128.0/1839.97.128.1 to 39.97.191.25439.97.191.25516,382
13639.97.192.0/1839.97.192.1 to 39.97.255.25439.97.255.25516,382
13739.98.0.0/1839.98.0.1 to 39.98.63.25439.98.63.25516,382
13839.98.64.0/1839.98.64.1 to 39.98.127.25439.98.127.25516,382
13939.98.128.0/1839.98.128.1 to 39.98.191.25439.98.191.25516,382
14039.98.192.0/1839.98.192.1 to 39.98.255.25439.98.255.25516,382
14139.99.0.0/1839.99.0.1 to 39.99.63.25439.99.63.25516,382
14239.99.64.0/1839.99.64.1 to 39.99.127.25439.99.127.25516,382
14339.99.128.0/1839.99.128.1 to 39.99.191.25439.99.191.25516,382
14439.99.192.0/1839.99.192.1 to 39.99.255.25439.99.255.25516,382
14539.100.0.0/1839.100.0.1 to 39.100.63.25439.100.63.25516,382
14639.100.64.0/1839.100.64.1 to 39.100.127.25439.100.127.25516,382
14739.100.128.0/1839.100.128.1 to 39.100.191.25439.100.191.25516,382
14839.100.192.0/1839.100.192.1 to 39.100.255.25439.100.255.25516,382
14939.101.0.0/1839.101.0.1 to 39.101.63.25439.101.63.25516,382
15039.101.64.0/1839.101.64.1 to 39.101.127.25439.101.127.25516,382
15139.101.128.0/1839.101.128.1 to 39.101.191.25439.101.191.25516,382
15239.101.192.0/1839.101.192.1 to 39.101.255.25439.101.255.25516,382
15339.102.0.0/1839.102.0.1 to 39.102.63.25439.102.63.25516,382
15439.102.64.0/1839.102.64.1 to 39.102.127.25439.102.127.25516,382
15539.102.128.0/1839.102.128.1 to 39.102.191.25439.102.191.25516,382
15639.102.192.0/1839.102.192.1 to 39.102.255.25439.102.255.25516,382
15739.103.0.0/1839.103.0.1 to 39.103.63.25439.103.63.25516,382
15839.103.64.0/1839.103.64.1 to 39.103.127.25439.103.127.25516,382
15939.103.128.0/1839.103.128.1 to 39.103.191.25439.103.191.25516,382
16039.103.192.0/1839.103.192.1 to 39.103.255.25439.103.255.25516,382
16139.104.0.0/1839.104.0.1 to 39.104.63.25439.104.63.25516,382
16239.104.64.0/1839.104.64.1 to 39.104.127.25439.104.127.25516,382
16339.104.128.0/1839.104.128.1 to 39.104.191.25439.104.191.25516,382
16439.104.192.0/1839.104.192.1 to 39.104.255.25439.104.255.25516,382
16539.105.0.0/1839.105.0.1 to 39.105.63.25439.105.63.25516,382
16639.105.64.0/1839.105.64.1 to 39.105.127.25439.105.127.25516,382
16739.105.128.0/1839.105.128.1 to 39.105.191.25439.105.191.25516,382
16839.105.192.0/1839.105.192.1 to 39.105.255.25439.105.255.25516,382
16939.106.0.0/1839.106.0.1 to 39.106.63.25439.106.63.25516,382
17039.106.64.0/1839.106.64.1 to 39.106.127.25439.106.127.25516,382
17139.106.128.0/1839.106.128.1 to 39.106.191.25439.106.191.25516,382
17239.106.192.0/1839.106.192.1 to 39.106.255.25439.106.255.25516,382
17339.107.0.0/1839.107.0.1 to 39.107.63.25439.107.63.25516,382
17439.107.64.0/1839.107.64.1 to 39.107.127.25439.107.127.25516,382
17539.107.128.0/1839.107.128.1 to 39.107.191.25439.107.191.25516,382
17639.107.192.0/1839.107.192.1 to 39.107.255.25439.107.255.25516,382
17739.108.0.0/1839.108.0.1 to 39.108.63.25439.108.63.25516,382
17839.108.64.0/1839.108.64.1 to 39.108.127.25439.108.127.25516,382
17939.108.128.0/1839.108.128.1 to 39.108.191.25439.108.191.25516,382
18039.108.192.0/1839.108.192.1 to 39.108.255.25439.108.255.25516,382
18139.109.0.0/1839.109.0.1 to 39.109.63.25439.109.63.25516,382
18239.109.64.0/1839.109.64.1 to 39.109.127.25439.109.127.25516,382
18339.109.128.0/1839.109.128.1 to 39.109.191.25439.109.191.25516,382
18439.109.192.0/1839.109.192.1 to 39.109.255.25439.109.255.25516,382
18539.110.0.0/1839.110.0.1 to 39.110.63.25439.110.63.25516,382
18639.110.64.0/1839.110.64.1 to 39.110.127.25439.110.127.25516,382
18739.110.128.0/1839.110.128.1 to 39.110.191.25439.110.191.25516,382
18839.110.192.0/1839.110.192.1 to 39.110.255.25439.110.255.25516,382
18939.111.0.0/1839.111.0.1 to 39.111.63.25439.111.63.25516,382
19039.111.64.0/1839.111.64.1 to 39.111.127.25439.111.127.25516,382
19139.111.128.0/1839.111.128.1 to 39.111.191.25439.111.191.25516,382
19239.111.192.0/1839.111.192.1 to 39.111.255.25439.111.255.25516,382
19339.112.0.0/1839.112.0.1 to 39.112.63.25439.112.63.25516,382
19439.112.64.0/1839.112.64.1 to 39.112.127.25439.112.127.25516,382
19539.112.128.0/1839.112.128.1 to 39.112.191.25439.112.191.25516,382
19639.112.192.0/1839.112.192.1 to 39.112.255.25439.112.255.25516,382
19739.113.0.0/1839.113.0.1 to 39.113.63.25439.113.63.25516,382
19839.113.64.0/1839.113.64.1 to 39.113.127.25439.113.127.25516,382
19939.113.128.0/1839.113.128.1 to 39.113.191.25439.113.191.25516,382
20039.113.192.0/1839.113.192.1 to 39.113.255.25439.113.255.25516,382
20139.114.0.0/1839.114.0.1 to 39.114.63.25439.114.63.25516,382
20239.114.64.0/1839.114.64.1 to 39.114.127.25439.114.127.25516,382
20339.114.128.0/1839.114.128.1 to 39.114.191.25439.114.191.25516,382
20439.114.192.0/1839.114.192.1 to 39.114.255.25439.114.255.25516,382
20539.115.0.0/1839.115.0.1 to 39.115.63.25439.115.63.25516,382
20639.115.64.0/1839.115.64.1 to 39.115.127.25439.115.127.25516,382
20739.115.128.0/1839.115.128.1 to 39.115.191.25439.115.191.25516,382
20839.115.192.0/1839.115.192.1 to 39.115.255.25439.115.255.25516,382
20939.116.0.0/1839.116.0.1 to 39.116.63.25439.116.63.25516,382
21039.116.64.0/1839.116.64.1 to 39.116.127.25439.116.127.25516,382
21139.116.128.0/1839.116.128.1 to 39.116.191.25439.116.191.25516,382
21239.116.192.0/1839.116.192.1 to 39.116.255.25439.116.255.25516,382
21339.117.0.0/1839.117.0.1 to 39.117.63.25439.117.63.25516,382
21439.117.64.0/1839.117.64.1 to 39.117.127.25439.117.127.25516,382
21539.117.128.0/1839.117.128.1 to 39.117.191.25439.117.191.25516,382
21639.117.192.0/1839.117.192.1 to 39.117.255.25439.117.255.25516,382
21739.118.0.0/1839.118.0.1 to 39.118.63.25439.118.63.25516,382
21839.118.64.0/1839.118.64.1 to 39.118.127.25439.118.127.25516,382
21939.118.128.0/1839.118.128.1 to 39.118.191.25439.118.191.25516,382
22039.118.192.0/1839.118.192.1 to 39.118.255.25439.118.255.25516,382
22139.119.0.0/1839.119.0.1 to 39.119.63.25439.119.63.25516,382
22239.119.64.0/1839.119.64.1 to 39.119.127.25439.119.127.25516,382
22339.119.128.0/1839.119.128.1 to 39.119.191.25439.119.191.25516,382
22439.119.192.0/1839.119.192.1 to 39.119.255.25439.119.255.25516,382
22539.120.0.0/1839.120.0.1 to 39.120.63.25439.120.63.25516,382
22639.120.64.0/1839.120.64.1 to 39.120.127.25439.120.127.25516,382
22739.120.128.0/1839.120.128.1 to 39.120.191.25439.120.191.25516,382
22839.120.192.0/1839.120.192.1 to 39.120.255.25439.120.255.25516,382
22939.121.0.0/1839.121.0.1 to 39.121.63.25439.121.63.25516,382
23039.121.64.0/1839.121.64.1 to 39.121.127.25439.121.127.25516,382
23139.121.128.0/1839.121.128.1 to 39.121.191.25439.121.191.25516,382
23239.121.192.0/1839.121.192.1 to 39.121.255.25439.121.255.25516,382
23339.122.0.0/1839.122.0.1 to 39.122.63.25439.122.63.25516,382
23439.122.64.0/1839.122.64.1 to 39.122.127.25439.122.127.25516,382
23539.122.128.0/1839.122.128.1 to 39.122.191.25439.122.191.25516,382
23639.122.192.0/1839.122.192.1 to 39.122.255.25439.122.255.25516,382
23739.123.0.0/1839.123.0.1 to 39.123.63.25439.123.63.25516,382
23839.123.64.0/1839.123.64.1 to 39.123.127.25439.123.127.25516,382
23939.123.128.0/1839.123.128.1 to 39.123.191.25439.123.191.25516,382
24039.123.192.0/1839.123.192.1 to 39.123.255.25439.123.255.25516,382
24139.124.0.0/1839.124.0.1 to 39.124.63.25439.124.63.25516,382
24239.124.64.0/1839.124.64.1 to 39.124.127.25439.124.127.25516,382
24339.124.128.0/1839.124.128.1 to 39.124.191.25439.124.191.25516,382
24439.124.192.0/1839.124.192.1 to 39.124.255.25439.124.255.25516,382
24539.125.0.0/1839.125.0.1 to 39.125.63.25439.125.63.25516,382
24639.125.64.0/1839.125.64.1 to 39.125.127.25439.125.127.25516,382
24739.125.128.0/1839.125.128.1 to 39.125.191.25439.125.191.25516,382
24839.125.192.0/1839.125.192.1 to 39.125.255.25439.125.255.25516,382
24939.126.0.0/1839.126.0.1 to 39.126.63.25439.126.63.25516,382
25039.126.64.0/1839.126.64.1 to 39.126.127.25439.126.127.25516,382
25139.126.128.0/1839.126.128.1 to 39.126.191.25439.126.191.25516,382
25239.126.192.0/1839.126.192.1 to 39.126.255.25439.126.255.25516,382
25339.127.0.0/1839.127.0.1 to 39.127.63.25439.127.63.25516,382
25439.127.64.0/1839.127.64.1 to 39.127.127.25439.127.127.25516,382
25539.127.128.0/1839.127.128.1 to 39.127.191.25439.127.191.25516,382
25639.127.192.0/1839.127.192.1 to 39.127.255.25439.127.255.25516,382

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.