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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.

Network184.0.0.0/7
Usable hosts33,554,430
Subnet mask254.0.0.0
Addresses33,554,432
Network address
184.0.0.0
Broadcast address
185.255.255.255
First usable
184.0.0.1
Last usable
185.255.255.254
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 B8000000 · Integer 3087007744 to 3120562175
Reverse DNS zones
184.in-addr.arpa
185.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
Address10111000.00000000.00000000.00000000184.0.0.0
Subnet mask11111110.00000000.00000000.00000000254.0.0.0
Network10111000.00000000.00000000.00000000184.0.0.0
Broadcast10111001.11111111.11111111.11111111185.255.255.255
Split into smaller subnets/17
/8 (2)/9 (4)/10 (8)/11 (16)/12 (32)/13 (64)/14 (128)/15 (256)/16 (512)/17 (1,024)/18 (2,048)/19 (4,096)

184.0.0.0/7 makes 1,024 subnets of /17; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1184.0.0.0/17184.0.0.1 to 184.0.127.254184.0.127.25532,766
2184.0.128.0/17184.0.128.1 to 184.0.255.254184.0.255.25532,766
3184.1.0.0/17184.1.0.1 to 184.1.127.254184.1.127.25532,766
4184.1.128.0/17184.1.128.1 to 184.1.255.254184.1.255.25532,766
5184.2.0.0/17184.2.0.1 to 184.2.127.254184.2.127.25532,766
6184.2.128.0/17184.2.128.1 to 184.2.255.254184.2.255.25532,766
7184.3.0.0/17184.3.0.1 to 184.3.127.254184.3.127.25532,766
8184.3.128.0/17184.3.128.1 to 184.3.255.254184.3.255.25532,766
9184.4.0.0/17184.4.0.1 to 184.4.127.254184.4.127.25532,766
10184.4.128.0/17184.4.128.1 to 184.4.255.254184.4.255.25532,766
11184.5.0.0/17184.5.0.1 to 184.5.127.254184.5.127.25532,766
12184.5.128.0/17184.5.128.1 to 184.5.255.254184.5.255.25532,766
13184.6.0.0/17184.6.0.1 to 184.6.127.254184.6.127.25532,766
14184.6.128.0/17184.6.128.1 to 184.6.255.254184.6.255.25532,766
15184.7.0.0/17184.7.0.1 to 184.7.127.254184.7.127.25532,766
16184.7.128.0/17184.7.128.1 to 184.7.255.254184.7.255.25532,766
17184.8.0.0/17184.8.0.1 to 184.8.127.254184.8.127.25532,766
18184.8.128.0/17184.8.128.1 to 184.8.255.254184.8.255.25532,766
19184.9.0.0/17184.9.0.1 to 184.9.127.254184.9.127.25532,766
20184.9.128.0/17184.9.128.1 to 184.9.255.254184.9.255.25532,766
21184.10.0.0/17184.10.0.1 to 184.10.127.254184.10.127.25532,766
22184.10.128.0/17184.10.128.1 to 184.10.255.254184.10.255.25532,766
23184.11.0.0/17184.11.0.1 to 184.11.127.254184.11.127.25532,766
24184.11.128.0/17184.11.128.1 to 184.11.255.254184.11.255.25532,766
25184.12.0.0/17184.12.0.1 to 184.12.127.254184.12.127.25532,766
26184.12.128.0/17184.12.128.1 to 184.12.255.254184.12.255.25532,766
27184.13.0.0/17184.13.0.1 to 184.13.127.254184.13.127.25532,766
28184.13.128.0/17184.13.128.1 to 184.13.255.254184.13.255.25532,766
29184.14.0.0/17184.14.0.1 to 184.14.127.254184.14.127.25532,766
30184.14.128.0/17184.14.128.1 to 184.14.255.254184.14.255.25532,766
31184.15.0.0/17184.15.0.1 to 184.15.127.254184.15.127.25532,766
32184.15.128.0/17184.15.128.1 to 184.15.255.254184.15.255.25532,766
33184.16.0.0/17184.16.0.1 to 184.16.127.254184.16.127.25532,766
34184.16.128.0/17184.16.128.1 to 184.16.255.254184.16.255.25532,766
35184.17.0.0/17184.17.0.1 to 184.17.127.254184.17.127.25532,766
36184.17.128.0/17184.17.128.1 to 184.17.255.254184.17.255.25532,766
37184.18.0.0/17184.18.0.1 to 184.18.127.254184.18.127.25532,766
38184.18.128.0/17184.18.128.1 to 184.18.255.254184.18.255.25532,766
39184.19.0.0/17184.19.0.1 to 184.19.127.254184.19.127.25532,766
40184.19.128.0/17184.19.128.1 to 184.19.255.254184.19.255.25532,766
41184.20.0.0/17184.20.0.1 to 184.20.127.254184.20.127.25532,766
42184.20.128.0/17184.20.128.1 to 184.20.255.254184.20.255.25532,766
43184.21.0.0/17184.21.0.1 to 184.21.127.254184.21.127.25532,766
44184.21.128.0/17184.21.128.1 to 184.21.255.254184.21.255.25532,766
45184.22.0.0/17184.22.0.1 to 184.22.127.254184.22.127.25532,766
46184.22.128.0/17184.22.128.1 to 184.22.255.254184.22.255.25532,766
47184.23.0.0/17184.23.0.1 to 184.23.127.254184.23.127.25532,766
48184.23.128.0/17184.23.128.1 to 184.23.255.254184.23.255.25532,766
49184.24.0.0/17184.24.0.1 to 184.24.127.254184.24.127.25532,766
50184.24.128.0/17184.24.128.1 to 184.24.255.254184.24.255.25532,766
51184.25.0.0/17184.25.0.1 to 184.25.127.254184.25.127.25532,766
52184.25.128.0/17184.25.128.1 to 184.25.255.254184.25.255.25532,766
53184.26.0.0/17184.26.0.1 to 184.26.127.254184.26.127.25532,766
54184.26.128.0/17184.26.128.1 to 184.26.255.254184.26.255.25532,766
55184.27.0.0/17184.27.0.1 to 184.27.127.254184.27.127.25532,766
56184.27.128.0/17184.27.128.1 to 184.27.255.254184.27.255.25532,766
57184.28.0.0/17184.28.0.1 to 184.28.127.254184.28.127.25532,766
58184.28.128.0/17184.28.128.1 to 184.28.255.254184.28.255.25532,766
59184.29.0.0/17184.29.0.1 to 184.29.127.254184.29.127.25532,766
60184.29.128.0/17184.29.128.1 to 184.29.255.254184.29.255.25532,766
61184.30.0.0/17184.30.0.1 to 184.30.127.254184.30.127.25532,766
62184.30.128.0/17184.30.128.1 to 184.30.255.254184.30.255.25532,766
63184.31.0.0/17184.31.0.1 to 184.31.127.254184.31.127.25532,766
64184.31.128.0/17184.31.128.1 to 184.31.255.254184.31.255.25532,766
65184.32.0.0/17184.32.0.1 to 184.32.127.254184.32.127.25532,766
66184.32.128.0/17184.32.128.1 to 184.32.255.254184.32.255.25532,766
67184.33.0.0/17184.33.0.1 to 184.33.127.254184.33.127.25532,766
68184.33.128.0/17184.33.128.1 to 184.33.255.254184.33.255.25532,766
69184.34.0.0/17184.34.0.1 to 184.34.127.254184.34.127.25532,766
70184.34.128.0/17184.34.128.1 to 184.34.255.254184.34.255.25532,766
71184.35.0.0/17184.35.0.1 to 184.35.127.254184.35.127.25532,766
72184.35.128.0/17184.35.128.1 to 184.35.255.254184.35.255.25532,766
73184.36.0.0/17184.36.0.1 to 184.36.127.254184.36.127.25532,766
74184.36.128.0/17184.36.128.1 to 184.36.255.254184.36.255.25532,766
75184.37.0.0/17184.37.0.1 to 184.37.127.254184.37.127.25532,766
76184.37.128.0/17184.37.128.1 to 184.37.255.254184.37.255.25532,766
77184.38.0.0/17184.38.0.1 to 184.38.127.254184.38.127.25532,766
78184.38.128.0/17184.38.128.1 to 184.38.255.254184.38.255.25532,766
79184.39.0.0/17184.39.0.1 to 184.39.127.254184.39.127.25532,766
80184.39.128.0/17184.39.128.1 to 184.39.255.254184.39.255.25532,766
81184.40.0.0/17184.40.0.1 to 184.40.127.254184.40.127.25532,766
82184.40.128.0/17184.40.128.1 to 184.40.255.254184.40.255.25532,766
83184.41.0.0/17184.41.0.1 to 184.41.127.254184.41.127.25532,766
84184.41.128.0/17184.41.128.1 to 184.41.255.254184.41.255.25532,766
85184.42.0.0/17184.42.0.1 to 184.42.127.254184.42.127.25532,766
86184.42.128.0/17184.42.128.1 to 184.42.255.254184.42.255.25532,766
87184.43.0.0/17184.43.0.1 to 184.43.127.254184.43.127.25532,766
88184.43.128.0/17184.43.128.1 to 184.43.255.254184.43.255.25532,766
89184.44.0.0/17184.44.0.1 to 184.44.127.254184.44.127.25532,766
90184.44.128.0/17184.44.128.1 to 184.44.255.254184.44.255.25532,766
91184.45.0.0/17184.45.0.1 to 184.45.127.254184.45.127.25532,766
92184.45.128.0/17184.45.128.1 to 184.45.255.254184.45.255.25532,766
93184.46.0.0/17184.46.0.1 to 184.46.127.254184.46.127.25532,766
94184.46.128.0/17184.46.128.1 to 184.46.255.254184.46.255.25532,766
95184.47.0.0/17184.47.0.1 to 184.47.127.254184.47.127.25532,766
96184.47.128.0/17184.47.128.1 to 184.47.255.254184.47.255.25532,766
97184.48.0.0/17184.48.0.1 to 184.48.127.254184.48.127.25532,766
98184.48.128.0/17184.48.128.1 to 184.48.255.254184.48.255.25532,766
99184.49.0.0/17184.49.0.1 to 184.49.127.254184.49.127.25532,766
100184.49.128.0/17184.49.128.1 to 184.49.255.254184.49.255.25532,766
101184.50.0.0/17184.50.0.1 to 184.50.127.254184.50.127.25532,766
102184.50.128.0/17184.50.128.1 to 184.50.255.254184.50.255.25532,766
103184.51.0.0/17184.51.0.1 to 184.51.127.254184.51.127.25532,766
104184.51.128.0/17184.51.128.1 to 184.51.255.254184.51.255.25532,766
105184.52.0.0/17184.52.0.1 to 184.52.127.254184.52.127.25532,766
106184.52.128.0/17184.52.128.1 to 184.52.255.254184.52.255.25532,766
107184.53.0.0/17184.53.0.1 to 184.53.127.254184.53.127.25532,766
108184.53.128.0/17184.53.128.1 to 184.53.255.254184.53.255.25532,766
109184.54.0.0/17184.54.0.1 to 184.54.127.254184.54.127.25532,766
110184.54.128.0/17184.54.128.1 to 184.54.255.254184.54.255.25532,766
111184.55.0.0/17184.55.0.1 to 184.55.127.254184.55.127.25532,766
112184.55.128.0/17184.55.128.1 to 184.55.255.254184.55.255.25532,766
113184.56.0.0/17184.56.0.1 to 184.56.127.254184.56.127.25532,766
114184.56.128.0/17184.56.128.1 to 184.56.255.254184.56.255.25532,766
115184.57.0.0/17184.57.0.1 to 184.57.127.254184.57.127.25532,766
116184.57.128.0/17184.57.128.1 to 184.57.255.254184.57.255.25532,766
117184.58.0.0/17184.58.0.1 to 184.58.127.254184.58.127.25532,766
118184.58.128.0/17184.58.128.1 to 184.58.255.254184.58.255.25532,766
119184.59.0.0/17184.59.0.1 to 184.59.127.254184.59.127.25532,766
120184.59.128.0/17184.59.128.1 to 184.59.255.254184.59.255.25532,766
121184.60.0.0/17184.60.0.1 to 184.60.127.254184.60.127.25532,766
122184.60.128.0/17184.60.128.1 to 184.60.255.254184.60.255.25532,766
123184.61.0.0/17184.61.0.1 to 184.61.127.254184.61.127.25532,766
124184.61.128.0/17184.61.128.1 to 184.61.255.254184.61.255.25532,766
125184.62.0.0/17184.62.0.1 to 184.62.127.254184.62.127.25532,766
126184.62.128.0/17184.62.128.1 to 184.62.255.254184.62.255.25532,766
127184.63.0.0/17184.63.0.1 to 184.63.127.254184.63.127.25532,766
128184.63.128.0/17184.63.128.1 to 184.63.255.254184.63.255.25532,766
129184.64.0.0/17184.64.0.1 to 184.64.127.254184.64.127.25532,766
130184.64.128.0/17184.64.128.1 to 184.64.255.254184.64.255.25532,766
131184.65.0.0/17184.65.0.1 to 184.65.127.254184.65.127.25532,766
132184.65.128.0/17184.65.128.1 to 184.65.255.254184.65.255.25532,766
133184.66.0.0/17184.66.0.1 to 184.66.127.254184.66.127.25532,766
134184.66.128.0/17184.66.128.1 to 184.66.255.254184.66.255.25532,766
135184.67.0.0/17184.67.0.1 to 184.67.127.254184.67.127.25532,766
136184.67.128.0/17184.67.128.1 to 184.67.255.254184.67.255.25532,766
137184.68.0.0/17184.68.0.1 to 184.68.127.254184.68.127.25532,766
138184.68.128.0/17184.68.128.1 to 184.68.255.254184.68.255.25532,766
139184.69.0.0/17184.69.0.1 to 184.69.127.254184.69.127.25532,766
140184.69.128.0/17184.69.128.1 to 184.69.255.254184.69.255.25532,766
141184.70.0.0/17184.70.0.1 to 184.70.127.254184.70.127.25532,766
142184.70.128.0/17184.70.128.1 to 184.70.255.254184.70.255.25532,766
143184.71.0.0/17184.71.0.1 to 184.71.127.254184.71.127.25532,766
144184.71.128.0/17184.71.128.1 to 184.71.255.254184.71.255.25532,766
145184.72.0.0/17184.72.0.1 to 184.72.127.254184.72.127.25532,766
146184.72.128.0/17184.72.128.1 to 184.72.255.254184.72.255.25532,766
147184.73.0.0/17184.73.0.1 to 184.73.127.254184.73.127.25532,766
148184.73.128.0/17184.73.128.1 to 184.73.255.254184.73.255.25532,766
149184.74.0.0/17184.74.0.1 to 184.74.127.254184.74.127.25532,766
150184.74.128.0/17184.74.128.1 to 184.74.255.254184.74.255.25532,766
151184.75.0.0/17184.75.0.1 to 184.75.127.254184.75.127.25532,766
152184.75.128.0/17184.75.128.1 to 184.75.255.254184.75.255.25532,766
153184.76.0.0/17184.76.0.1 to 184.76.127.254184.76.127.25532,766
154184.76.128.0/17184.76.128.1 to 184.76.255.254184.76.255.25532,766
155184.77.0.0/17184.77.0.1 to 184.77.127.254184.77.127.25532,766
156184.77.128.0/17184.77.128.1 to 184.77.255.254184.77.255.25532,766
157184.78.0.0/17184.78.0.1 to 184.78.127.254184.78.127.25532,766
158184.78.128.0/17184.78.128.1 to 184.78.255.254184.78.255.25532,766
159184.79.0.0/17184.79.0.1 to 184.79.127.254184.79.127.25532,766
160184.79.128.0/17184.79.128.1 to 184.79.255.254184.79.255.25532,766
161184.80.0.0/17184.80.0.1 to 184.80.127.254184.80.127.25532,766
162184.80.128.0/17184.80.128.1 to 184.80.255.254184.80.255.25532,766
163184.81.0.0/17184.81.0.1 to 184.81.127.254184.81.127.25532,766
164184.81.128.0/17184.81.128.1 to 184.81.255.254184.81.255.25532,766
165184.82.0.0/17184.82.0.1 to 184.82.127.254184.82.127.25532,766
166184.82.128.0/17184.82.128.1 to 184.82.255.254184.82.255.25532,766
167184.83.0.0/17184.83.0.1 to 184.83.127.254184.83.127.25532,766
168184.83.128.0/17184.83.128.1 to 184.83.255.254184.83.255.25532,766
169184.84.0.0/17184.84.0.1 to 184.84.127.254184.84.127.25532,766
170184.84.128.0/17184.84.128.1 to 184.84.255.254184.84.255.25532,766
171184.85.0.0/17184.85.0.1 to 184.85.127.254184.85.127.25532,766
172184.85.128.0/17184.85.128.1 to 184.85.255.254184.85.255.25532,766
173184.86.0.0/17184.86.0.1 to 184.86.127.254184.86.127.25532,766
174184.86.128.0/17184.86.128.1 to 184.86.255.254184.86.255.25532,766
175184.87.0.0/17184.87.0.1 to 184.87.127.254184.87.127.25532,766
176184.87.128.0/17184.87.128.1 to 184.87.255.254184.87.255.25532,766
177184.88.0.0/17184.88.0.1 to 184.88.127.254184.88.127.25532,766
178184.88.128.0/17184.88.128.1 to 184.88.255.254184.88.255.25532,766
179184.89.0.0/17184.89.0.1 to 184.89.127.254184.89.127.25532,766
180184.89.128.0/17184.89.128.1 to 184.89.255.254184.89.255.25532,766
181184.90.0.0/17184.90.0.1 to 184.90.127.254184.90.127.25532,766
182184.90.128.0/17184.90.128.1 to 184.90.255.254184.90.255.25532,766
183184.91.0.0/17184.91.0.1 to 184.91.127.254184.91.127.25532,766
184184.91.128.0/17184.91.128.1 to 184.91.255.254184.91.255.25532,766
185184.92.0.0/17184.92.0.1 to 184.92.127.254184.92.127.25532,766
186184.92.128.0/17184.92.128.1 to 184.92.255.254184.92.255.25532,766
187184.93.0.0/17184.93.0.1 to 184.93.127.254184.93.127.25532,766
188184.93.128.0/17184.93.128.1 to 184.93.255.254184.93.255.25532,766
189184.94.0.0/17184.94.0.1 to 184.94.127.254184.94.127.25532,766
190184.94.128.0/17184.94.128.1 to 184.94.255.254184.94.255.25532,766
191184.95.0.0/17184.95.0.1 to 184.95.127.254184.95.127.25532,766
192184.95.128.0/17184.95.128.1 to 184.95.255.254184.95.255.25532,766
193184.96.0.0/17184.96.0.1 to 184.96.127.254184.96.127.25532,766
194184.96.128.0/17184.96.128.1 to 184.96.255.254184.96.255.25532,766
195184.97.0.0/17184.97.0.1 to 184.97.127.254184.97.127.25532,766
196184.97.128.0/17184.97.128.1 to 184.97.255.254184.97.255.25532,766
197184.98.0.0/17184.98.0.1 to 184.98.127.254184.98.127.25532,766
198184.98.128.0/17184.98.128.1 to 184.98.255.254184.98.255.25532,766
199184.99.0.0/17184.99.0.1 to 184.99.127.254184.99.127.25532,766
200184.99.128.0/17184.99.128.1 to 184.99.255.254184.99.255.25532,766
201184.100.0.0/17184.100.0.1 to 184.100.127.254184.100.127.25532,766
202184.100.128.0/17184.100.128.1 to 184.100.255.254184.100.255.25532,766
203184.101.0.0/17184.101.0.1 to 184.101.127.254184.101.127.25532,766
204184.101.128.0/17184.101.128.1 to 184.101.255.254184.101.255.25532,766
205184.102.0.0/17184.102.0.1 to 184.102.127.254184.102.127.25532,766
206184.102.128.0/17184.102.128.1 to 184.102.255.254184.102.255.25532,766
207184.103.0.0/17184.103.0.1 to 184.103.127.254184.103.127.25532,766
208184.103.128.0/17184.103.128.1 to 184.103.255.254184.103.255.25532,766
209184.104.0.0/17184.104.0.1 to 184.104.127.254184.104.127.25532,766
210184.104.128.0/17184.104.128.1 to 184.104.255.254184.104.255.25532,766
211184.105.0.0/17184.105.0.1 to 184.105.127.254184.105.127.25532,766
212184.105.128.0/17184.105.128.1 to 184.105.255.254184.105.255.25532,766
213184.106.0.0/17184.106.0.1 to 184.106.127.254184.106.127.25532,766
214184.106.128.0/17184.106.128.1 to 184.106.255.254184.106.255.25532,766
215184.107.0.0/17184.107.0.1 to 184.107.127.254184.107.127.25532,766
216184.107.128.0/17184.107.128.1 to 184.107.255.254184.107.255.25532,766
217184.108.0.0/17184.108.0.1 to 184.108.127.254184.108.127.25532,766
218184.108.128.0/17184.108.128.1 to 184.108.255.254184.108.255.25532,766
219184.109.0.0/17184.109.0.1 to 184.109.127.254184.109.127.25532,766
220184.109.128.0/17184.109.128.1 to 184.109.255.254184.109.255.25532,766
221184.110.0.0/17184.110.0.1 to 184.110.127.254184.110.127.25532,766
222184.110.128.0/17184.110.128.1 to 184.110.255.254184.110.255.25532,766
223184.111.0.0/17184.111.0.1 to 184.111.127.254184.111.127.25532,766
224184.111.128.0/17184.111.128.1 to 184.111.255.254184.111.255.25532,766
225184.112.0.0/17184.112.0.1 to 184.112.127.254184.112.127.25532,766
226184.112.128.0/17184.112.128.1 to 184.112.255.254184.112.255.25532,766
227184.113.0.0/17184.113.0.1 to 184.113.127.254184.113.127.25532,766
228184.113.128.0/17184.113.128.1 to 184.113.255.254184.113.255.25532,766
229184.114.0.0/17184.114.0.1 to 184.114.127.254184.114.127.25532,766
230184.114.128.0/17184.114.128.1 to 184.114.255.254184.114.255.25532,766
231184.115.0.0/17184.115.0.1 to 184.115.127.254184.115.127.25532,766
232184.115.128.0/17184.115.128.1 to 184.115.255.254184.115.255.25532,766
233184.116.0.0/17184.116.0.1 to 184.116.127.254184.116.127.25532,766
234184.116.128.0/17184.116.128.1 to 184.116.255.254184.116.255.25532,766
235184.117.0.0/17184.117.0.1 to 184.117.127.254184.117.127.25532,766
236184.117.128.0/17184.117.128.1 to 184.117.255.254184.117.255.25532,766
237184.118.0.0/17184.118.0.1 to 184.118.127.254184.118.127.25532,766
238184.118.128.0/17184.118.128.1 to 184.118.255.254184.118.255.25532,766
239184.119.0.0/17184.119.0.1 to 184.119.127.254184.119.127.25532,766
240184.119.128.0/17184.119.128.1 to 184.119.255.254184.119.255.25532,766
241184.120.0.0/17184.120.0.1 to 184.120.127.254184.120.127.25532,766
242184.120.128.0/17184.120.128.1 to 184.120.255.254184.120.255.25532,766
243184.121.0.0/17184.121.0.1 to 184.121.127.254184.121.127.25532,766
244184.121.128.0/17184.121.128.1 to 184.121.255.254184.121.255.25532,766
245184.122.0.0/17184.122.0.1 to 184.122.127.254184.122.127.25532,766
246184.122.128.0/17184.122.128.1 to 184.122.255.254184.122.255.25532,766
247184.123.0.0/17184.123.0.1 to 184.123.127.254184.123.127.25532,766
248184.123.128.0/17184.123.128.1 to 184.123.255.254184.123.255.25532,766
249184.124.0.0/17184.124.0.1 to 184.124.127.254184.124.127.25532,766
250184.124.128.0/17184.124.128.1 to 184.124.255.254184.124.255.25532,766
251184.125.0.0/17184.125.0.1 to 184.125.127.254184.125.127.25532,766
252184.125.128.0/17184.125.128.1 to 184.125.255.254184.125.255.25532,766
253184.126.0.0/17184.126.0.1 to 184.126.127.254184.126.127.25532,766
254184.126.128.0/17184.126.128.1 to 184.126.255.254184.126.255.25532,766
255184.127.0.0/17184.127.0.1 to 184.127.127.254184.127.127.25532,766
256184.127.128.0/17184.127.128.1 to 184.127.255.254184.127.255.25532,766

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.