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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.

Network132.0.0.0/7
Usable hosts33,554,430
Subnet mask254.0.0.0
Addresses33,554,432
Network address
132.0.0.0
Broadcast address
133.255.255.255
First usable
132.0.0.1
Last usable
133.255.255.254
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
B (default /16)
As numbers
Hex 84000000 · Integer 2214592512 to 2248146943
Reverse DNS zones
132.in-addr.arpa
133.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
Address10000100.00000000.00000000.00000000132.0.0.0
Subnet mask11111110.00000000.00000000.00000000254.0.0.0
Network10000100.00000000.00000000.00000000132.0.0.0
Broadcast10000101.11111111.11111111.11111111133.255.255.255
Split into smaller subnets/15
/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)

132.0.0.0/7 makes 256 subnets of /15.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1132.0.0.0/15132.0.0.1 to 132.1.255.254132.1.255.255131,070
2132.2.0.0/15132.2.0.1 to 132.3.255.254132.3.255.255131,070
3132.4.0.0/15132.4.0.1 to 132.5.255.254132.5.255.255131,070
4132.6.0.0/15132.6.0.1 to 132.7.255.254132.7.255.255131,070
5132.8.0.0/15132.8.0.1 to 132.9.255.254132.9.255.255131,070
6132.10.0.0/15132.10.0.1 to 132.11.255.254132.11.255.255131,070
7132.12.0.0/15132.12.0.1 to 132.13.255.254132.13.255.255131,070
8132.14.0.0/15132.14.0.1 to 132.15.255.254132.15.255.255131,070
9132.16.0.0/15132.16.0.1 to 132.17.255.254132.17.255.255131,070
10132.18.0.0/15132.18.0.1 to 132.19.255.254132.19.255.255131,070
11132.20.0.0/15132.20.0.1 to 132.21.255.254132.21.255.255131,070
12132.22.0.0/15132.22.0.1 to 132.23.255.254132.23.255.255131,070
13132.24.0.0/15132.24.0.1 to 132.25.255.254132.25.255.255131,070
14132.26.0.0/15132.26.0.1 to 132.27.255.254132.27.255.255131,070
15132.28.0.0/15132.28.0.1 to 132.29.255.254132.29.255.255131,070
16132.30.0.0/15132.30.0.1 to 132.31.255.254132.31.255.255131,070
17132.32.0.0/15132.32.0.1 to 132.33.255.254132.33.255.255131,070
18132.34.0.0/15132.34.0.1 to 132.35.255.254132.35.255.255131,070
19132.36.0.0/15132.36.0.1 to 132.37.255.254132.37.255.255131,070
20132.38.0.0/15132.38.0.1 to 132.39.255.254132.39.255.255131,070
21132.40.0.0/15132.40.0.1 to 132.41.255.254132.41.255.255131,070
22132.42.0.0/15132.42.0.1 to 132.43.255.254132.43.255.255131,070
23132.44.0.0/15132.44.0.1 to 132.45.255.254132.45.255.255131,070
24132.46.0.0/15132.46.0.1 to 132.47.255.254132.47.255.255131,070
25132.48.0.0/15132.48.0.1 to 132.49.255.254132.49.255.255131,070
26132.50.0.0/15132.50.0.1 to 132.51.255.254132.51.255.255131,070
27132.52.0.0/15132.52.0.1 to 132.53.255.254132.53.255.255131,070
28132.54.0.0/15132.54.0.1 to 132.55.255.254132.55.255.255131,070
29132.56.0.0/15132.56.0.1 to 132.57.255.254132.57.255.255131,070
30132.58.0.0/15132.58.0.1 to 132.59.255.254132.59.255.255131,070
31132.60.0.0/15132.60.0.1 to 132.61.255.254132.61.255.255131,070
32132.62.0.0/15132.62.0.1 to 132.63.255.254132.63.255.255131,070
33132.64.0.0/15132.64.0.1 to 132.65.255.254132.65.255.255131,070
34132.66.0.0/15132.66.0.1 to 132.67.255.254132.67.255.255131,070
35132.68.0.0/15132.68.0.1 to 132.69.255.254132.69.255.255131,070
36132.70.0.0/15132.70.0.1 to 132.71.255.254132.71.255.255131,070
37132.72.0.0/15132.72.0.1 to 132.73.255.254132.73.255.255131,070
38132.74.0.0/15132.74.0.1 to 132.75.255.254132.75.255.255131,070
39132.76.0.0/15132.76.0.1 to 132.77.255.254132.77.255.255131,070
40132.78.0.0/15132.78.0.1 to 132.79.255.254132.79.255.255131,070
41132.80.0.0/15132.80.0.1 to 132.81.255.254132.81.255.255131,070
42132.82.0.0/15132.82.0.1 to 132.83.255.254132.83.255.255131,070
43132.84.0.0/15132.84.0.1 to 132.85.255.254132.85.255.255131,070
44132.86.0.0/15132.86.0.1 to 132.87.255.254132.87.255.255131,070
45132.88.0.0/15132.88.0.1 to 132.89.255.254132.89.255.255131,070
46132.90.0.0/15132.90.0.1 to 132.91.255.254132.91.255.255131,070
47132.92.0.0/15132.92.0.1 to 132.93.255.254132.93.255.255131,070
48132.94.0.0/15132.94.0.1 to 132.95.255.254132.95.255.255131,070
49132.96.0.0/15132.96.0.1 to 132.97.255.254132.97.255.255131,070
50132.98.0.0/15132.98.0.1 to 132.99.255.254132.99.255.255131,070
51132.100.0.0/15132.100.0.1 to 132.101.255.254132.101.255.255131,070
52132.102.0.0/15132.102.0.1 to 132.103.255.254132.103.255.255131,070
53132.104.0.0/15132.104.0.1 to 132.105.255.254132.105.255.255131,070
54132.106.0.0/15132.106.0.1 to 132.107.255.254132.107.255.255131,070
55132.108.0.0/15132.108.0.1 to 132.109.255.254132.109.255.255131,070
56132.110.0.0/15132.110.0.1 to 132.111.255.254132.111.255.255131,070
57132.112.0.0/15132.112.0.1 to 132.113.255.254132.113.255.255131,070
58132.114.0.0/15132.114.0.1 to 132.115.255.254132.115.255.255131,070
59132.116.0.0/15132.116.0.1 to 132.117.255.254132.117.255.255131,070
60132.118.0.0/15132.118.0.1 to 132.119.255.254132.119.255.255131,070
61132.120.0.0/15132.120.0.1 to 132.121.255.254132.121.255.255131,070
62132.122.0.0/15132.122.0.1 to 132.123.255.254132.123.255.255131,070
63132.124.0.0/15132.124.0.1 to 132.125.255.254132.125.255.255131,070
64132.126.0.0/15132.126.0.1 to 132.127.255.254132.127.255.255131,070
65132.128.0.0/15132.128.0.1 to 132.129.255.254132.129.255.255131,070
66132.130.0.0/15132.130.0.1 to 132.131.255.254132.131.255.255131,070
67132.132.0.0/15132.132.0.1 to 132.133.255.254132.133.255.255131,070
68132.134.0.0/15132.134.0.1 to 132.135.255.254132.135.255.255131,070
69132.136.0.0/15132.136.0.1 to 132.137.255.254132.137.255.255131,070
70132.138.0.0/15132.138.0.1 to 132.139.255.254132.139.255.255131,070
71132.140.0.0/15132.140.0.1 to 132.141.255.254132.141.255.255131,070
72132.142.0.0/15132.142.0.1 to 132.143.255.254132.143.255.255131,070
73132.144.0.0/15132.144.0.1 to 132.145.255.254132.145.255.255131,070
74132.146.0.0/15132.146.0.1 to 132.147.255.254132.147.255.255131,070
75132.148.0.0/15132.148.0.1 to 132.149.255.254132.149.255.255131,070
76132.150.0.0/15132.150.0.1 to 132.151.255.254132.151.255.255131,070
77132.152.0.0/15132.152.0.1 to 132.153.255.254132.153.255.255131,070
78132.154.0.0/15132.154.0.1 to 132.155.255.254132.155.255.255131,070
79132.156.0.0/15132.156.0.1 to 132.157.255.254132.157.255.255131,070
80132.158.0.0/15132.158.0.1 to 132.159.255.254132.159.255.255131,070
81132.160.0.0/15132.160.0.1 to 132.161.255.254132.161.255.255131,070
82132.162.0.0/15132.162.0.1 to 132.163.255.254132.163.255.255131,070
83132.164.0.0/15132.164.0.1 to 132.165.255.254132.165.255.255131,070
84132.166.0.0/15132.166.0.1 to 132.167.255.254132.167.255.255131,070
85132.168.0.0/15132.168.0.1 to 132.169.255.254132.169.255.255131,070
86132.170.0.0/15132.170.0.1 to 132.171.255.254132.171.255.255131,070
87132.172.0.0/15132.172.0.1 to 132.173.255.254132.173.255.255131,070
88132.174.0.0/15132.174.0.1 to 132.175.255.254132.175.255.255131,070
89132.176.0.0/15132.176.0.1 to 132.177.255.254132.177.255.255131,070
90132.178.0.0/15132.178.0.1 to 132.179.255.254132.179.255.255131,070
91132.180.0.0/15132.180.0.1 to 132.181.255.254132.181.255.255131,070
92132.182.0.0/15132.182.0.1 to 132.183.255.254132.183.255.255131,070
93132.184.0.0/15132.184.0.1 to 132.185.255.254132.185.255.255131,070
94132.186.0.0/15132.186.0.1 to 132.187.255.254132.187.255.255131,070
95132.188.0.0/15132.188.0.1 to 132.189.255.254132.189.255.255131,070
96132.190.0.0/15132.190.0.1 to 132.191.255.254132.191.255.255131,070
97132.192.0.0/15132.192.0.1 to 132.193.255.254132.193.255.255131,070
98132.194.0.0/15132.194.0.1 to 132.195.255.254132.195.255.255131,070
99132.196.0.0/15132.196.0.1 to 132.197.255.254132.197.255.255131,070
100132.198.0.0/15132.198.0.1 to 132.199.255.254132.199.255.255131,070
101132.200.0.0/15132.200.0.1 to 132.201.255.254132.201.255.255131,070
102132.202.0.0/15132.202.0.1 to 132.203.255.254132.203.255.255131,070
103132.204.0.0/15132.204.0.1 to 132.205.255.254132.205.255.255131,070
104132.206.0.0/15132.206.0.1 to 132.207.255.254132.207.255.255131,070
105132.208.0.0/15132.208.0.1 to 132.209.255.254132.209.255.255131,070
106132.210.0.0/15132.210.0.1 to 132.211.255.254132.211.255.255131,070
107132.212.0.0/15132.212.0.1 to 132.213.255.254132.213.255.255131,070
108132.214.0.0/15132.214.0.1 to 132.215.255.254132.215.255.255131,070
109132.216.0.0/15132.216.0.1 to 132.217.255.254132.217.255.255131,070
110132.218.0.0/15132.218.0.1 to 132.219.255.254132.219.255.255131,070
111132.220.0.0/15132.220.0.1 to 132.221.255.254132.221.255.255131,070
112132.222.0.0/15132.222.0.1 to 132.223.255.254132.223.255.255131,070
113132.224.0.0/15132.224.0.1 to 132.225.255.254132.225.255.255131,070
114132.226.0.0/15132.226.0.1 to 132.227.255.254132.227.255.255131,070
115132.228.0.0/15132.228.0.1 to 132.229.255.254132.229.255.255131,070
116132.230.0.0/15132.230.0.1 to 132.231.255.254132.231.255.255131,070
117132.232.0.0/15132.232.0.1 to 132.233.255.254132.233.255.255131,070
118132.234.0.0/15132.234.0.1 to 132.235.255.254132.235.255.255131,070
119132.236.0.0/15132.236.0.1 to 132.237.255.254132.237.255.255131,070
120132.238.0.0/15132.238.0.1 to 132.239.255.254132.239.255.255131,070
121132.240.0.0/15132.240.0.1 to 132.241.255.254132.241.255.255131,070
122132.242.0.0/15132.242.0.1 to 132.243.255.254132.243.255.255131,070
123132.244.0.0/15132.244.0.1 to 132.245.255.254132.245.255.255131,070
124132.246.0.0/15132.246.0.1 to 132.247.255.254132.247.255.255131,070
125132.248.0.0/15132.248.0.1 to 132.249.255.254132.249.255.255131,070
126132.250.0.0/15132.250.0.1 to 132.251.255.254132.251.255.255131,070
127132.252.0.0/15132.252.0.1 to 132.253.255.254132.253.255.255131,070
128132.254.0.0/15132.254.0.1 to 132.255.255.254132.255.255.255131,070
129133.0.0.0/15133.0.0.1 to 133.1.255.254133.1.255.255131,070
130133.2.0.0/15133.2.0.1 to 133.3.255.254133.3.255.255131,070
131133.4.0.0/15133.4.0.1 to 133.5.255.254133.5.255.255131,070
132133.6.0.0/15133.6.0.1 to 133.7.255.254133.7.255.255131,070
133133.8.0.0/15133.8.0.1 to 133.9.255.254133.9.255.255131,070
134133.10.0.0/15133.10.0.1 to 133.11.255.254133.11.255.255131,070
135133.12.0.0/15133.12.0.1 to 133.13.255.254133.13.255.255131,070
136133.14.0.0/15133.14.0.1 to 133.15.255.254133.15.255.255131,070
137133.16.0.0/15133.16.0.1 to 133.17.255.254133.17.255.255131,070
138133.18.0.0/15133.18.0.1 to 133.19.255.254133.19.255.255131,070
139133.20.0.0/15133.20.0.1 to 133.21.255.254133.21.255.255131,070
140133.22.0.0/15133.22.0.1 to 133.23.255.254133.23.255.255131,070
141133.24.0.0/15133.24.0.1 to 133.25.255.254133.25.255.255131,070
142133.26.0.0/15133.26.0.1 to 133.27.255.254133.27.255.255131,070
143133.28.0.0/15133.28.0.1 to 133.29.255.254133.29.255.255131,070
144133.30.0.0/15133.30.0.1 to 133.31.255.254133.31.255.255131,070
145133.32.0.0/15133.32.0.1 to 133.33.255.254133.33.255.255131,070
146133.34.0.0/15133.34.0.1 to 133.35.255.254133.35.255.255131,070
147133.36.0.0/15133.36.0.1 to 133.37.255.254133.37.255.255131,070
148133.38.0.0/15133.38.0.1 to 133.39.255.254133.39.255.255131,070
149133.40.0.0/15133.40.0.1 to 133.41.255.254133.41.255.255131,070
150133.42.0.0/15133.42.0.1 to 133.43.255.254133.43.255.255131,070
151133.44.0.0/15133.44.0.1 to 133.45.255.254133.45.255.255131,070
152133.46.0.0/15133.46.0.1 to 133.47.255.254133.47.255.255131,070
153133.48.0.0/15133.48.0.1 to 133.49.255.254133.49.255.255131,070
154133.50.0.0/15133.50.0.1 to 133.51.255.254133.51.255.255131,070
155133.52.0.0/15133.52.0.1 to 133.53.255.254133.53.255.255131,070
156133.54.0.0/15133.54.0.1 to 133.55.255.254133.55.255.255131,070
157133.56.0.0/15133.56.0.1 to 133.57.255.254133.57.255.255131,070
158133.58.0.0/15133.58.0.1 to 133.59.255.254133.59.255.255131,070
159133.60.0.0/15133.60.0.1 to 133.61.255.254133.61.255.255131,070
160133.62.0.0/15133.62.0.1 to 133.63.255.254133.63.255.255131,070
161133.64.0.0/15133.64.0.1 to 133.65.255.254133.65.255.255131,070
162133.66.0.0/15133.66.0.1 to 133.67.255.254133.67.255.255131,070
163133.68.0.0/15133.68.0.1 to 133.69.255.254133.69.255.255131,070
164133.70.0.0/15133.70.0.1 to 133.71.255.254133.71.255.255131,070
165133.72.0.0/15133.72.0.1 to 133.73.255.254133.73.255.255131,070
166133.74.0.0/15133.74.0.1 to 133.75.255.254133.75.255.255131,070
167133.76.0.0/15133.76.0.1 to 133.77.255.254133.77.255.255131,070
168133.78.0.0/15133.78.0.1 to 133.79.255.254133.79.255.255131,070
169133.80.0.0/15133.80.0.1 to 133.81.255.254133.81.255.255131,070
170133.82.0.0/15133.82.0.1 to 133.83.255.254133.83.255.255131,070
171133.84.0.0/15133.84.0.1 to 133.85.255.254133.85.255.255131,070
172133.86.0.0/15133.86.0.1 to 133.87.255.254133.87.255.255131,070
173133.88.0.0/15133.88.0.1 to 133.89.255.254133.89.255.255131,070
174133.90.0.0/15133.90.0.1 to 133.91.255.254133.91.255.255131,070
175133.92.0.0/15133.92.0.1 to 133.93.255.254133.93.255.255131,070
176133.94.0.0/15133.94.0.1 to 133.95.255.254133.95.255.255131,070
177133.96.0.0/15133.96.0.1 to 133.97.255.254133.97.255.255131,070
178133.98.0.0/15133.98.0.1 to 133.99.255.254133.99.255.255131,070
179133.100.0.0/15133.100.0.1 to 133.101.255.254133.101.255.255131,070
180133.102.0.0/15133.102.0.1 to 133.103.255.254133.103.255.255131,070
181133.104.0.0/15133.104.0.1 to 133.105.255.254133.105.255.255131,070
182133.106.0.0/15133.106.0.1 to 133.107.255.254133.107.255.255131,070
183133.108.0.0/15133.108.0.1 to 133.109.255.254133.109.255.255131,070
184133.110.0.0/15133.110.0.1 to 133.111.255.254133.111.255.255131,070
185133.112.0.0/15133.112.0.1 to 133.113.255.254133.113.255.255131,070
186133.114.0.0/15133.114.0.1 to 133.115.255.254133.115.255.255131,070
187133.116.0.0/15133.116.0.1 to 133.117.255.254133.117.255.255131,070
188133.118.0.0/15133.118.0.1 to 133.119.255.254133.119.255.255131,070
189133.120.0.0/15133.120.0.1 to 133.121.255.254133.121.255.255131,070
190133.122.0.0/15133.122.0.1 to 133.123.255.254133.123.255.255131,070
191133.124.0.0/15133.124.0.1 to 133.125.255.254133.125.255.255131,070
192133.126.0.0/15133.126.0.1 to 133.127.255.254133.127.255.255131,070
193133.128.0.0/15133.128.0.1 to 133.129.255.254133.129.255.255131,070
194133.130.0.0/15133.130.0.1 to 133.131.255.254133.131.255.255131,070
195133.132.0.0/15133.132.0.1 to 133.133.255.254133.133.255.255131,070
196133.134.0.0/15133.134.0.1 to 133.135.255.254133.135.255.255131,070
197133.136.0.0/15133.136.0.1 to 133.137.255.254133.137.255.255131,070
198133.138.0.0/15133.138.0.1 to 133.139.255.254133.139.255.255131,070
199133.140.0.0/15133.140.0.1 to 133.141.255.254133.141.255.255131,070
200133.142.0.0/15133.142.0.1 to 133.143.255.254133.143.255.255131,070
201133.144.0.0/15133.144.0.1 to 133.145.255.254133.145.255.255131,070
202133.146.0.0/15133.146.0.1 to 133.147.255.254133.147.255.255131,070
203133.148.0.0/15133.148.0.1 to 133.149.255.254133.149.255.255131,070
204133.150.0.0/15133.150.0.1 to 133.151.255.254133.151.255.255131,070
205133.152.0.0/15133.152.0.1 to 133.153.255.254133.153.255.255131,070
206133.154.0.0/15133.154.0.1 to 133.155.255.254133.155.255.255131,070
207133.156.0.0/15133.156.0.1 to 133.157.255.254133.157.255.255131,070
208133.158.0.0/15133.158.0.1 to 133.159.255.254133.159.255.255131,070
209133.160.0.0/15133.160.0.1 to 133.161.255.254133.161.255.255131,070
210133.162.0.0/15133.162.0.1 to 133.163.255.254133.163.255.255131,070
211133.164.0.0/15133.164.0.1 to 133.165.255.254133.165.255.255131,070
212133.166.0.0/15133.166.0.1 to 133.167.255.254133.167.255.255131,070
213133.168.0.0/15133.168.0.1 to 133.169.255.254133.169.255.255131,070
214133.170.0.0/15133.170.0.1 to 133.171.255.254133.171.255.255131,070
215133.172.0.0/15133.172.0.1 to 133.173.255.254133.173.255.255131,070
216133.174.0.0/15133.174.0.1 to 133.175.255.254133.175.255.255131,070
217133.176.0.0/15133.176.0.1 to 133.177.255.254133.177.255.255131,070
218133.178.0.0/15133.178.0.1 to 133.179.255.254133.179.255.255131,070
219133.180.0.0/15133.180.0.1 to 133.181.255.254133.181.255.255131,070
220133.182.0.0/15133.182.0.1 to 133.183.255.254133.183.255.255131,070
221133.184.0.0/15133.184.0.1 to 133.185.255.254133.185.255.255131,070
222133.186.0.0/15133.186.0.1 to 133.187.255.254133.187.255.255131,070
223133.188.0.0/15133.188.0.1 to 133.189.255.254133.189.255.255131,070
224133.190.0.0/15133.190.0.1 to 133.191.255.254133.191.255.255131,070
225133.192.0.0/15133.192.0.1 to 133.193.255.254133.193.255.255131,070
226133.194.0.0/15133.194.0.1 to 133.195.255.254133.195.255.255131,070
227133.196.0.0/15133.196.0.1 to 133.197.255.254133.197.255.255131,070
228133.198.0.0/15133.198.0.1 to 133.199.255.254133.199.255.255131,070
229133.200.0.0/15133.200.0.1 to 133.201.255.254133.201.255.255131,070
230133.202.0.0/15133.202.0.1 to 133.203.255.254133.203.255.255131,070
231133.204.0.0/15133.204.0.1 to 133.205.255.254133.205.255.255131,070
232133.206.0.0/15133.206.0.1 to 133.207.255.254133.207.255.255131,070
233133.208.0.0/15133.208.0.1 to 133.209.255.254133.209.255.255131,070
234133.210.0.0/15133.210.0.1 to 133.211.255.254133.211.255.255131,070
235133.212.0.0/15133.212.0.1 to 133.213.255.254133.213.255.255131,070
236133.214.0.0/15133.214.0.1 to 133.215.255.254133.215.255.255131,070
237133.216.0.0/15133.216.0.1 to 133.217.255.254133.217.255.255131,070
238133.218.0.0/15133.218.0.1 to 133.219.255.254133.219.255.255131,070
239133.220.0.0/15133.220.0.1 to 133.221.255.254133.221.255.255131,070
240133.222.0.0/15133.222.0.1 to 133.223.255.254133.223.255.255131,070
241133.224.0.0/15133.224.0.1 to 133.225.255.254133.225.255.255131,070
242133.226.0.0/15133.226.0.1 to 133.227.255.254133.227.255.255131,070
243133.228.0.0/15133.228.0.1 to 133.229.255.254133.229.255.255131,070
244133.230.0.0/15133.230.0.1 to 133.231.255.254133.231.255.255131,070
245133.232.0.0/15133.232.0.1 to 133.233.255.254133.233.255.255131,070
246133.234.0.0/15133.234.0.1 to 133.235.255.254133.235.255.255131,070
247133.236.0.0/15133.236.0.1 to 133.237.255.254133.237.255.255131,070
248133.238.0.0/15133.238.0.1 to 133.239.255.254133.239.255.255131,070
249133.240.0.0/15133.240.0.1 to 133.241.255.254133.241.255.255131,070
250133.242.0.0/15133.242.0.1 to 133.243.255.254133.243.255.255131,070
251133.244.0.0/15133.244.0.1 to 133.245.255.254133.245.255.255131,070
252133.246.0.0/15133.246.0.1 to 133.247.255.254133.247.255.255131,070
253133.248.0.0/15133.248.0.1 to 133.249.255.254133.249.255.255131,070
254133.250.0.0/15133.250.0.1 to 133.251.255.254133.251.255.255131,070
255133.252.0.0/15133.252.0.1 to 133.253.255.254133.253.255.255131,070
256133.254.0.0/15133.254.0.1 to 133.255.255.254133.255.255.255131,070

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.