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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.

Network190.0.0.0/7
Usable hosts33,554,430
Subnet mask254.0.0.0
Addresses33,554,432
Network address
190.0.0.0
Broadcast address
191.255.255.255
First usable
190.0.0.1
Last usable
191.255.255.254
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 BE000000 · Integer 3187671040 to 3221225471
Reverse DNS zones
190.in-addr.arpa
191.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
Address10111110.00000000.00000000.00000000190.0.0.0
Subnet mask11111110.00000000.00000000.00000000254.0.0.0
Network10111110.00000000.00000000.00000000190.0.0.0
Broadcast10111111.11111111.11111111.11111111191.255.255.255
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)

190.0.0.0/7 makes 1,024 subnets of /17; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1190.0.0.0/17190.0.0.1 to 190.0.127.254190.0.127.25532,766
2190.0.128.0/17190.0.128.1 to 190.0.255.254190.0.255.25532,766
3190.1.0.0/17190.1.0.1 to 190.1.127.254190.1.127.25532,766
4190.1.128.0/17190.1.128.1 to 190.1.255.254190.1.255.25532,766
5190.2.0.0/17190.2.0.1 to 190.2.127.254190.2.127.25532,766
6190.2.128.0/17190.2.128.1 to 190.2.255.254190.2.255.25532,766
7190.3.0.0/17190.3.0.1 to 190.3.127.254190.3.127.25532,766
8190.3.128.0/17190.3.128.1 to 190.3.255.254190.3.255.25532,766
9190.4.0.0/17190.4.0.1 to 190.4.127.254190.4.127.25532,766
10190.4.128.0/17190.4.128.1 to 190.4.255.254190.4.255.25532,766
11190.5.0.0/17190.5.0.1 to 190.5.127.254190.5.127.25532,766
12190.5.128.0/17190.5.128.1 to 190.5.255.254190.5.255.25532,766
13190.6.0.0/17190.6.0.1 to 190.6.127.254190.6.127.25532,766
14190.6.128.0/17190.6.128.1 to 190.6.255.254190.6.255.25532,766
15190.7.0.0/17190.7.0.1 to 190.7.127.254190.7.127.25532,766
16190.7.128.0/17190.7.128.1 to 190.7.255.254190.7.255.25532,766
17190.8.0.0/17190.8.0.1 to 190.8.127.254190.8.127.25532,766
18190.8.128.0/17190.8.128.1 to 190.8.255.254190.8.255.25532,766
19190.9.0.0/17190.9.0.1 to 190.9.127.254190.9.127.25532,766
20190.9.128.0/17190.9.128.1 to 190.9.255.254190.9.255.25532,766
21190.10.0.0/17190.10.0.1 to 190.10.127.254190.10.127.25532,766
22190.10.128.0/17190.10.128.1 to 190.10.255.254190.10.255.25532,766
23190.11.0.0/17190.11.0.1 to 190.11.127.254190.11.127.25532,766
24190.11.128.0/17190.11.128.1 to 190.11.255.254190.11.255.25532,766
25190.12.0.0/17190.12.0.1 to 190.12.127.254190.12.127.25532,766
26190.12.128.0/17190.12.128.1 to 190.12.255.254190.12.255.25532,766
27190.13.0.0/17190.13.0.1 to 190.13.127.254190.13.127.25532,766
28190.13.128.0/17190.13.128.1 to 190.13.255.254190.13.255.25532,766
29190.14.0.0/17190.14.0.1 to 190.14.127.254190.14.127.25532,766
30190.14.128.0/17190.14.128.1 to 190.14.255.254190.14.255.25532,766
31190.15.0.0/17190.15.0.1 to 190.15.127.254190.15.127.25532,766
32190.15.128.0/17190.15.128.1 to 190.15.255.254190.15.255.25532,766
33190.16.0.0/17190.16.0.1 to 190.16.127.254190.16.127.25532,766
34190.16.128.0/17190.16.128.1 to 190.16.255.254190.16.255.25532,766
35190.17.0.0/17190.17.0.1 to 190.17.127.254190.17.127.25532,766
36190.17.128.0/17190.17.128.1 to 190.17.255.254190.17.255.25532,766
37190.18.0.0/17190.18.0.1 to 190.18.127.254190.18.127.25532,766
38190.18.128.0/17190.18.128.1 to 190.18.255.254190.18.255.25532,766
39190.19.0.0/17190.19.0.1 to 190.19.127.254190.19.127.25532,766
40190.19.128.0/17190.19.128.1 to 190.19.255.254190.19.255.25532,766
41190.20.0.0/17190.20.0.1 to 190.20.127.254190.20.127.25532,766
42190.20.128.0/17190.20.128.1 to 190.20.255.254190.20.255.25532,766
43190.21.0.0/17190.21.0.1 to 190.21.127.254190.21.127.25532,766
44190.21.128.0/17190.21.128.1 to 190.21.255.254190.21.255.25532,766
45190.22.0.0/17190.22.0.1 to 190.22.127.254190.22.127.25532,766
46190.22.128.0/17190.22.128.1 to 190.22.255.254190.22.255.25532,766
47190.23.0.0/17190.23.0.1 to 190.23.127.254190.23.127.25532,766
48190.23.128.0/17190.23.128.1 to 190.23.255.254190.23.255.25532,766
49190.24.0.0/17190.24.0.1 to 190.24.127.254190.24.127.25532,766
50190.24.128.0/17190.24.128.1 to 190.24.255.254190.24.255.25532,766
51190.25.0.0/17190.25.0.1 to 190.25.127.254190.25.127.25532,766
52190.25.128.0/17190.25.128.1 to 190.25.255.254190.25.255.25532,766
53190.26.0.0/17190.26.0.1 to 190.26.127.254190.26.127.25532,766
54190.26.128.0/17190.26.128.1 to 190.26.255.254190.26.255.25532,766
55190.27.0.0/17190.27.0.1 to 190.27.127.254190.27.127.25532,766
56190.27.128.0/17190.27.128.1 to 190.27.255.254190.27.255.25532,766
57190.28.0.0/17190.28.0.1 to 190.28.127.254190.28.127.25532,766
58190.28.128.0/17190.28.128.1 to 190.28.255.254190.28.255.25532,766
59190.29.0.0/17190.29.0.1 to 190.29.127.254190.29.127.25532,766
60190.29.128.0/17190.29.128.1 to 190.29.255.254190.29.255.25532,766
61190.30.0.0/17190.30.0.1 to 190.30.127.254190.30.127.25532,766
62190.30.128.0/17190.30.128.1 to 190.30.255.254190.30.255.25532,766
63190.31.0.0/17190.31.0.1 to 190.31.127.254190.31.127.25532,766
64190.31.128.0/17190.31.128.1 to 190.31.255.254190.31.255.25532,766
65190.32.0.0/17190.32.0.1 to 190.32.127.254190.32.127.25532,766
66190.32.128.0/17190.32.128.1 to 190.32.255.254190.32.255.25532,766
67190.33.0.0/17190.33.0.1 to 190.33.127.254190.33.127.25532,766
68190.33.128.0/17190.33.128.1 to 190.33.255.254190.33.255.25532,766
69190.34.0.0/17190.34.0.1 to 190.34.127.254190.34.127.25532,766
70190.34.128.0/17190.34.128.1 to 190.34.255.254190.34.255.25532,766
71190.35.0.0/17190.35.0.1 to 190.35.127.254190.35.127.25532,766
72190.35.128.0/17190.35.128.1 to 190.35.255.254190.35.255.25532,766
73190.36.0.0/17190.36.0.1 to 190.36.127.254190.36.127.25532,766
74190.36.128.0/17190.36.128.1 to 190.36.255.254190.36.255.25532,766
75190.37.0.0/17190.37.0.1 to 190.37.127.254190.37.127.25532,766
76190.37.128.0/17190.37.128.1 to 190.37.255.254190.37.255.25532,766
77190.38.0.0/17190.38.0.1 to 190.38.127.254190.38.127.25532,766
78190.38.128.0/17190.38.128.1 to 190.38.255.254190.38.255.25532,766
79190.39.0.0/17190.39.0.1 to 190.39.127.254190.39.127.25532,766
80190.39.128.0/17190.39.128.1 to 190.39.255.254190.39.255.25532,766
81190.40.0.0/17190.40.0.1 to 190.40.127.254190.40.127.25532,766
82190.40.128.0/17190.40.128.1 to 190.40.255.254190.40.255.25532,766
83190.41.0.0/17190.41.0.1 to 190.41.127.254190.41.127.25532,766
84190.41.128.0/17190.41.128.1 to 190.41.255.254190.41.255.25532,766
85190.42.0.0/17190.42.0.1 to 190.42.127.254190.42.127.25532,766
86190.42.128.0/17190.42.128.1 to 190.42.255.254190.42.255.25532,766
87190.43.0.0/17190.43.0.1 to 190.43.127.254190.43.127.25532,766
88190.43.128.0/17190.43.128.1 to 190.43.255.254190.43.255.25532,766
89190.44.0.0/17190.44.0.1 to 190.44.127.254190.44.127.25532,766
90190.44.128.0/17190.44.128.1 to 190.44.255.254190.44.255.25532,766
91190.45.0.0/17190.45.0.1 to 190.45.127.254190.45.127.25532,766
92190.45.128.0/17190.45.128.1 to 190.45.255.254190.45.255.25532,766
93190.46.0.0/17190.46.0.1 to 190.46.127.254190.46.127.25532,766
94190.46.128.0/17190.46.128.1 to 190.46.255.254190.46.255.25532,766
95190.47.0.0/17190.47.0.1 to 190.47.127.254190.47.127.25532,766
96190.47.128.0/17190.47.128.1 to 190.47.255.254190.47.255.25532,766
97190.48.0.0/17190.48.0.1 to 190.48.127.254190.48.127.25532,766
98190.48.128.0/17190.48.128.1 to 190.48.255.254190.48.255.25532,766
99190.49.0.0/17190.49.0.1 to 190.49.127.254190.49.127.25532,766
100190.49.128.0/17190.49.128.1 to 190.49.255.254190.49.255.25532,766
101190.50.0.0/17190.50.0.1 to 190.50.127.254190.50.127.25532,766
102190.50.128.0/17190.50.128.1 to 190.50.255.254190.50.255.25532,766
103190.51.0.0/17190.51.0.1 to 190.51.127.254190.51.127.25532,766
104190.51.128.0/17190.51.128.1 to 190.51.255.254190.51.255.25532,766
105190.52.0.0/17190.52.0.1 to 190.52.127.254190.52.127.25532,766
106190.52.128.0/17190.52.128.1 to 190.52.255.254190.52.255.25532,766
107190.53.0.0/17190.53.0.1 to 190.53.127.254190.53.127.25532,766
108190.53.128.0/17190.53.128.1 to 190.53.255.254190.53.255.25532,766
109190.54.0.0/17190.54.0.1 to 190.54.127.254190.54.127.25532,766
110190.54.128.0/17190.54.128.1 to 190.54.255.254190.54.255.25532,766
111190.55.0.0/17190.55.0.1 to 190.55.127.254190.55.127.25532,766
112190.55.128.0/17190.55.128.1 to 190.55.255.254190.55.255.25532,766
113190.56.0.0/17190.56.0.1 to 190.56.127.254190.56.127.25532,766
114190.56.128.0/17190.56.128.1 to 190.56.255.254190.56.255.25532,766
115190.57.0.0/17190.57.0.1 to 190.57.127.254190.57.127.25532,766
116190.57.128.0/17190.57.128.1 to 190.57.255.254190.57.255.25532,766
117190.58.0.0/17190.58.0.1 to 190.58.127.254190.58.127.25532,766
118190.58.128.0/17190.58.128.1 to 190.58.255.254190.58.255.25532,766
119190.59.0.0/17190.59.0.1 to 190.59.127.254190.59.127.25532,766
120190.59.128.0/17190.59.128.1 to 190.59.255.254190.59.255.25532,766
121190.60.0.0/17190.60.0.1 to 190.60.127.254190.60.127.25532,766
122190.60.128.0/17190.60.128.1 to 190.60.255.254190.60.255.25532,766
123190.61.0.0/17190.61.0.1 to 190.61.127.254190.61.127.25532,766
124190.61.128.0/17190.61.128.1 to 190.61.255.254190.61.255.25532,766
125190.62.0.0/17190.62.0.1 to 190.62.127.254190.62.127.25532,766
126190.62.128.0/17190.62.128.1 to 190.62.255.254190.62.255.25532,766
127190.63.0.0/17190.63.0.1 to 190.63.127.254190.63.127.25532,766
128190.63.128.0/17190.63.128.1 to 190.63.255.254190.63.255.25532,766
129190.64.0.0/17190.64.0.1 to 190.64.127.254190.64.127.25532,766
130190.64.128.0/17190.64.128.1 to 190.64.255.254190.64.255.25532,766
131190.65.0.0/17190.65.0.1 to 190.65.127.254190.65.127.25532,766
132190.65.128.0/17190.65.128.1 to 190.65.255.254190.65.255.25532,766
133190.66.0.0/17190.66.0.1 to 190.66.127.254190.66.127.25532,766
134190.66.128.0/17190.66.128.1 to 190.66.255.254190.66.255.25532,766
135190.67.0.0/17190.67.0.1 to 190.67.127.254190.67.127.25532,766
136190.67.128.0/17190.67.128.1 to 190.67.255.254190.67.255.25532,766
137190.68.0.0/17190.68.0.1 to 190.68.127.254190.68.127.25532,766
138190.68.128.0/17190.68.128.1 to 190.68.255.254190.68.255.25532,766
139190.69.0.0/17190.69.0.1 to 190.69.127.254190.69.127.25532,766
140190.69.128.0/17190.69.128.1 to 190.69.255.254190.69.255.25532,766
141190.70.0.0/17190.70.0.1 to 190.70.127.254190.70.127.25532,766
142190.70.128.0/17190.70.128.1 to 190.70.255.254190.70.255.25532,766
143190.71.0.0/17190.71.0.1 to 190.71.127.254190.71.127.25532,766
144190.71.128.0/17190.71.128.1 to 190.71.255.254190.71.255.25532,766
145190.72.0.0/17190.72.0.1 to 190.72.127.254190.72.127.25532,766
146190.72.128.0/17190.72.128.1 to 190.72.255.254190.72.255.25532,766
147190.73.0.0/17190.73.0.1 to 190.73.127.254190.73.127.25532,766
148190.73.128.0/17190.73.128.1 to 190.73.255.254190.73.255.25532,766
149190.74.0.0/17190.74.0.1 to 190.74.127.254190.74.127.25532,766
150190.74.128.0/17190.74.128.1 to 190.74.255.254190.74.255.25532,766
151190.75.0.0/17190.75.0.1 to 190.75.127.254190.75.127.25532,766
152190.75.128.0/17190.75.128.1 to 190.75.255.254190.75.255.25532,766
153190.76.0.0/17190.76.0.1 to 190.76.127.254190.76.127.25532,766
154190.76.128.0/17190.76.128.1 to 190.76.255.254190.76.255.25532,766
155190.77.0.0/17190.77.0.1 to 190.77.127.254190.77.127.25532,766
156190.77.128.0/17190.77.128.1 to 190.77.255.254190.77.255.25532,766
157190.78.0.0/17190.78.0.1 to 190.78.127.254190.78.127.25532,766
158190.78.128.0/17190.78.128.1 to 190.78.255.254190.78.255.25532,766
159190.79.0.0/17190.79.0.1 to 190.79.127.254190.79.127.25532,766
160190.79.128.0/17190.79.128.1 to 190.79.255.254190.79.255.25532,766
161190.80.0.0/17190.80.0.1 to 190.80.127.254190.80.127.25532,766
162190.80.128.0/17190.80.128.1 to 190.80.255.254190.80.255.25532,766
163190.81.0.0/17190.81.0.1 to 190.81.127.254190.81.127.25532,766
164190.81.128.0/17190.81.128.1 to 190.81.255.254190.81.255.25532,766
165190.82.0.0/17190.82.0.1 to 190.82.127.254190.82.127.25532,766
166190.82.128.0/17190.82.128.1 to 190.82.255.254190.82.255.25532,766
167190.83.0.0/17190.83.0.1 to 190.83.127.254190.83.127.25532,766
168190.83.128.0/17190.83.128.1 to 190.83.255.254190.83.255.25532,766
169190.84.0.0/17190.84.0.1 to 190.84.127.254190.84.127.25532,766
170190.84.128.0/17190.84.128.1 to 190.84.255.254190.84.255.25532,766
171190.85.0.0/17190.85.0.1 to 190.85.127.254190.85.127.25532,766
172190.85.128.0/17190.85.128.1 to 190.85.255.254190.85.255.25532,766
173190.86.0.0/17190.86.0.1 to 190.86.127.254190.86.127.25532,766
174190.86.128.0/17190.86.128.1 to 190.86.255.254190.86.255.25532,766
175190.87.0.0/17190.87.0.1 to 190.87.127.254190.87.127.25532,766
176190.87.128.0/17190.87.128.1 to 190.87.255.254190.87.255.25532,766
177190.88.0.0/17190.88.0.1 to 190.88.127.254190.88.127.25532,766
178190.88.128.0/17190.88.128.1 to 190.88.255.254190.88.255.25532,766
179190.89.0.0/17190.89.0.1 to 190.89.127.254190.89.127.25532,766
180190.89.128.0/17190.89.128.1 to 190.89.255.254190.89.255.25532,766
181190.90.0.0/17190.90.0.1 to 190.90.127.254190.90.127.25532,766
182190.90.128.0/17190.90.128.1 to 190.90.255.254190.90.255.25532,766
183190.91.0.0/17190.91.0.1 to 190.91.127.254190.91.127.25532,766
184190.91.128.0/17190.91.128.1 to 190.91.255.254190.91.255.25532,766
185190.92.0.0/17190.92.0.1 to 190.92.127.254190.92.127.25532,766
186190.92.128.0/17190.92.128.1 to 190.92.255.254190.92.255.25532,766
187190.93.0.0/17190.93.0.1 to 190.93.127.254190.93.127.25532,766
188190.93.128.0/17190.93.128.1 to 190.93.255.254190.93.255.25532,766
189190.94.0.0/17190.94.0.1 to 190.94.127.254190.94.127.25532,766
190190.94.128.0/17190.94.128.1 to 190.94.255.254190.94.255.25532,766
191190.95.0.0/17190.95.0.1 to 190.95.127.254190.95.127.25532,766
192190.95.128.0/17190.95.128.1 to 190.95.255.254190.95.255.25532,766
193190.96.0.0/17190.96.0.1 to 190.96.127.254190.96.127.25532,766
194190.96.128.0/17190.96.128.1 to 190.96.255.254190.96.255.25532,766
195190.97.0.0/17190.97.0.1 to 190.97.127.254190.97.127.25532,766
196190.97.128.0/17190.97.128.1 to 190.97.255.254190.97.255.25532,766
197190.98.0.0/17190.98.0.1 to 190.98.127.254190.98.127.25532,766
198190.98.128.0/17190.98.128.1 to 190.98.255.254190.98.255.25532,766
199190.99.0.0/17190.99.0.1 to 190.99.127.254190.99.127.25532,766
200190.99.128.0/17190.99.128.1 to 190.99.255.254190.99.255.25532,766
201190.100.0.0/17190.100.0.1 to 190.100.127.254190.100.127.25532,766
202190.100.128.0/17190.100.128.1 to 190.100.255.254190.100.255.25532,766
203190.101.0.0/17190.101.0.1 to 190.101.127.254190.101.127.25532,766
204190.101.128.0/17190.101.128.1 to 190.101.255.254190.101.255.25532,766
205190.102.0.0/17190.102.0.1 to 190.102.127.254190.102.127.25532,766
206190.102.128.0/17190.102.128.1 to 190.102.255.254190.102.255.25532,766
207190.103.0.0/17190.103.0.1 to 190.103.127.254190.103.127.25532,766
208190.103.128.0/17190.103.128.1 to 190.103.255.254190.103.255.25532,766
209190.104.0.0/17190.104.0.1 to 190.104.127.254190.104.127.25532,766
210190.104.128.0/17190.104.128.1 to 190.104.255.254190.104.255.25532,766
211190.105.0.0/17190.105.0.1 to 190.105.127.254190.105.127.25532,766
212190.105.128.0/17190.105.128.1 to 190.105.255.254190.105.255.25532,766
213190.106.0.0/17190.106.0.1 to 190.106.127.254190.106.127.25532,766
214190.106.128.0/17190.106.128.1 to 190.106.255.254190.106.255.25532,766
215190.107.0.0/17190.107.0.1 to 190.107.127.254190.107.127.25532,766
216190.107.128.0/17190.107.128.1 to 190.107.255.254190.107.255.25532,766
217190.108.0.0/17190.108.0.1 to 190.108.127.254190.108.127.25532,766
218190.108.128.0/17190.108.128.1 to 190.108.255.254190.108.255.25532,766
219190.109.0.0/17190.109.0.1 to 190.109.127.254190.109.127.25532,766
220190.109.128.0/17190.109.128.1 to 190.109.255.254190.109.255.25532,766
221190.110.0.0/17190.110.0.1 to 190.110.127.254190.110.127.25532,766
222190.110.128.0/17190.110.128.1 to 190.110.255.254190.110.255.25532,766
223190.111.0.0/17190.111.0.1 to 190.111.127.254190.111.127.25532,766
224190.111.128.0/17190.111.128.1 to 190.111.255.254190.111.255.25532,766
225190.112.0.0/17190.112.0.1 to 190.112.127.254190.112.127.25532,766
226190.112.128.0/17190.112.128.1 to 190.112.255.254190.112.255.25532,766
227190.113.0.0/17190.113.0.1 to 190.113.127.254190.113.127.25532,766
228190.113.128.0/17190.113.128.1 to 190.113.255.254190.113.255.25532,766
229190.114.0.0/17190.114.0.1 to 190.114.127.254190.114.127.25532,766
230190.114.128.0/17190.114.128.1 to 190.114.255.254190.114.255.25532,766
231190.115.0.0/17190.115.0.1 to 190.115.127.254190.115.127.25532,766
232190.115.128.0/17190.115.128.1 to 190.115.255.254190.115.255.25532,766
233190.116.0.0/17190.116.0.1 to 190.116.127.254190.116.127.25532,766
234190.116.128.0/17190.116.128.1 to 190.116.255.254190.116.255.25532,766
235190.117.0.0/17190.117.0.1 to 190.117.127.254190.117.127.25532,766
236190.117.128.0/17190.117.128.1 to 190.117.255.254190.117.255.25532,766
237190.118.0.0/17190.118.0.1 to 190.118.127.254190.118.127.25532,766
238190.118.128.0/17190.118.128.1 to 190.118.255.254190.118.255.25532,766
239190.119.0.0/17190.119.0.1 to 190.119.127.254190.119.127.25532,766
240190.119.128.0/17190.119.128.1 to 190.119.255.254190.119.255.25532,766
241190.120.0.0/17190.120.0.1 to 190.120.127.254190.120.127.25532,766
242190.120.128.0/17190.120.128.1 to 190.120.255.254190.120.255.25532,766
243190.121.0.0/17190.121.0.1 to 190.121.127.254190.121.127.25532,766
244190.121.128.0/17190.121.128.1 to 190.121.255.254190.121.255.25532,766
245190.122.0.0/17190.122.0.1 to 190.122.127.254190.122.127.25532,766
246190.122.128.0/17190.122.128.1 to 190.122.255.254190.122.255.25532,766
247190.123.0.0/17190.123.0.1 to 190.123.127.254190.123.127.25532,766
248190.123.128.0/17190.123.128.1 to 190.123.255.254190.123.255.25532,766
249190.124.0.0/17190.124.0.1 to 190.124.127.254190.124.127.25532,766
250190.124.128.0/17190.124.128.1 to 190.124.255.254190.124.255.25532,766
251190.125.0.0/17190.125.0.1 to 190.125.127.254190.125.127.25532,766
252190.125.128.0/17190.125.128.1 to 190.125.255.254190.125.255.25532,766
253190.126.0.0/17190.126.0.1 to 190.126.127.254190.126.127.25532,766
254190.126.128.0/17190.126.128.1 to 190.126.255.254190.126.255.25532,766
255190.127.0.0/17190.127.0.1 to 190.127.127.254190.127.127.25532,766
256190.127.128.0/17190.127.128.1 to 190.127.255.254190.127.255.25532,766

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.