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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.

Network160.0.0.0/6
Usable hosts67,108,862
Subnet mask252.0.0.0
Addresses67,108,864
Network address
160.0.0.0
Broadcast address
163.255.255.255
First usable
160.0.0.1
Last usable
163.255.255.254
Usable hosts
67,108,862 (67,108,864 less the network and broadcast addresses)
Subnet mask
252.0.0.0
Wildcard mask
3.255.255.255 (Cisco ACLs, OSPF)
Prefix length
/6
Type
Public public
Old class
B (default /16)
As numbers
Hex A0000000 · Integer 2684354560 to 2751463423
Reverse DNS zones
160.in-addr.arpa
161.in-addr.arpa
162.in-addr.arpa
163.in-addr.arpa
/6 is not on a 8-bit boundary, so it takes 4 /8 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address10100000.00000000.00000000.00000000160.0.0.0
Subnet mask11111100.00000000.00000000.00000000252.0.0.0
Network10100000.00000000.00000000.00000000160.0.0.0
Broadcast10100011.11111111.11111111.11111111163.255.255.255
Split into smaller subnets/17
/7 (2)/8 (4)/9 (8)/10 (16)/11 (32)/12 (64)/13 (128)/14 (256)/15 (512)/16 (1,024)/17 (2,048)/18 (4,096)

160.0.0.0/6 makes 2,048 subnets of /17; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1160.0.0.0/17160.0.0.1 to 160.0.127.254160.0.127.25532,766
2160.0.128.0/17160.0.128.1 to 160.0.255.254160.0.255.25532,766
3160.1.0.0/17160.1.0.1 to 160.1.127.254160.1.127.25532,766
4160.1.128.0/17160.1.128.1 to 160.1.255.254160.1.255.25532,766
5160.2.0.0/17160.2.0.1 to 160.2.127.254160.2.127.25532,766
6160.2.128.0/17160.2.128.1 to 160.2.255.254160.2.255.25532,766
7160.3.0.0/17160.3.0.1 to 160.3.127.254160.3.127.25532,766
8160.3.128.0/17160.3.128.1 to 160.3.255.254160.3.255.25532,766
9160.4.0.0/17160.4.0.1 to 160.4.127.254160.4.127.25532,766
10160.4.128.0/17160.4.128.1 to 160.4.255.254160.4.255.25532,766
11160.5.0.0/17160.5.0.1 to 160.5.127.254160.5.127.25532,766
12160.5.128.0/17160.5.128.1 to 160.5.255.254160.5.255.25532,766
13160.6.0.0/17160.6.0.1 to 160.6.127.254160.6.127.25532,766
14160.6.128.0/17160.6.128.1 to 160.6.255.254160.6.255.25532,766
15160.7.0.0/17160.7.0.1 to 160.7.127.254160.7.127.25532,766
16160.7.128.0/17160.7.128.1 to 160.7.255.254160.7.255.25532,766
17160.8.0.0/17160.8.0.1 to 160.8.127.254160.8.127.25532,766
18160.8.128.0/17160.8.128.1 to 160.8.255.254160.8.255.25532,766
19160.9.0.0/17160.9.0.1 to 160.9.127.254160.9.127.25532,766
20160.9.128.0/17160.9.128.1 to 160.9.255.254160.9.255.25532,766
21160.10.0.0/17160.10.0.1 to 160.10.127.254160.10.127.25532,766
22160.10.128.0/17160.10.128.1 to 160.10.255.254160.10.255.25532,766
23160.11.0.0/17160.11.0.1 to 160.11.127.254160.11.127.25532,766
24160.11.128.0/17160.11.128.1 to 160.11.255.254160.11.255.25532,766
25160.12.0.0/17160.12.0.1 to 160.12.127.254160.12.127.25532,766
26160.12.128.0/17160.12.128.1 to 160.12.255.254160.12.255.25532,766
27160.13.0.0/17160.13.0.1 to 160.13.127.254160.13.127.25532,766
28160.13.128.0/17160.13.128.1 to 160.13.255.254160.13.255.25532,766
29160.14.0.0/17160.14.0.1 to 160.14.127.254160.14.127.25532,766
30160.14.128.0/17160.14.128.1 to 160.14.255.254160.14.255.25532,766
31160.15.0.0/17160.15.0.1 to 160.15.127.254160.15.127.25532,766
32160.15.128.0/17160.15.128.1 to 160.15.255.254160.15.255.25532,766
33160.16.0.0/17160.16.0.1 to 160.16.127.254160.16.127.25532,766
34160.16.128.0/17160.16.128.1 to 160.16.255.254160.16.255.25532,766
35160.17.0.0/17160.17.0.1 to 160.17.127.254160.17.127.25532,766
36160.17.128.0/17160.17.128.1 to 160.17.255.254160.17.255.25532,766
37160.18.0.0/17160.18.0.1 to 160.18.127.254160.18.127.25532,766
38160.18.128.0/17160.18.128.1 to 160.18.255.254160.18.255.25532,766
39160.19.0.0/17160.19.0.1 to 160.19.127.254160.19.127.25532,766
40160.19.128.0/17160.19.128.1 to 160.19.255.254160.19.255.25532,766
41160.20.0.0/17160.20.0.1 to 160.20.127.254160.20.127.25532,766
42160.20.128.0/17160.20.128.1 to 160.20.255.254160.20.255.25532,766
43160.21.0.0/17160.21.0.1 to 160.21.127.254160.21.127.25532,766
44160.21.128.0/17160.21.128.1 to 160.21.255.254160.21.255.25532,766
45160.22.0.0/17160.22.0.1 to 160.22.127.254160.22.127.25532,766
46160.22.128.0/17160.22.128.1 to 160.22.255.254160.22.255.25532,766
47160.23.0.0/17160.23.0.1 to 160.23.127.254160.23.127.25532,766
48160.23.128.0/17160.23.128.1 to 160.23.255.254160.23.255.25532,766
49160.24.0.0/17160.24.0.1 to 160.24.127.254160.24.127.25532,766
50160.24.128.0/17160.24.128.1 to 160.24.255.254160.24.255.25532,766
51160.25.0.0/17160.25.0.1 to 160.25.127.254160.25.127.25532,766
52160.25.128.0/17160.25.128.1 to 160.25.255.254160.25.255.25532,766
53160.26.0.0/17160.26.0.1 to 160.26.127.254160.26.127.25532,766
54160.26.128.0/17160.26.128.1 to 160.26.255.254160.26.255.25532,766
55160.27.0.0/17160.27.0.1 to 160.27.127.254160.27.127.25532,766
56160.27.128.0/17160.27.128.1 to 160.27.255.254160.27.255.25532,766
57160.28.0.0/17160.28.0.1 to 160.28.127.254160.28.127.25532,766
58160.28.128.0/17160.28.128.1 to 160.28.255.254160.28.255.25532,766
59160.29.0.0/17160.29.0.1 to 160.29.127.254160.29.127.25532,766
60160.29.128.0/17160.29.128.1 to 160.29.255.254160.29.255.25532,766
61160.30.0.0/17160.30.0.1 to 160.30.127.254160.30.127.25532,766
62160.30.128.0/17160.30.128.1 to 160.30.255.254160.30.255.25532,766
63160.31.0.0/17160.31.0.1 to 160.31.127.254160.31.127.25532,766
64160.31.128.0/17160.31.128.1 to 160.31.255.254160.31.255.25532,766
65160.32.0.0/17160.32.0.1 to 160.32.127.254160.32.127.25532,766
66160.32.128.0/17160.32.128.1 to 160.32.255.254160.32.255.25532,766
67160.33.0.0/17160.33.0.1 to 160.33.127.254160.33.127.25532,766
68160.33.128.0/17160.33.128.1 to 160.33.255.254160.33.255.25532,766
69160.34.0.0/17160.34.0.1 to 160.34.127.254160.34.127.25532,766
70160.34.128.0/17160.34.128.1 to 160.34.255.254160.34.255.25532,766
71160.35.0.0/17160.35.0.1 to 160.35.127.254160.35.127.25532,766
72160.35.128.0/17160.35.128.1 to 160.35.255.254160.35.255.25532,766
73160.36.0.0/17160.36.0.1 to 160.36.127.254160.36.127.25532,766
74160.36.128.0/17160.36.128.1 to 160.36.255.254160.36.255.25532,766
75160.37.0.0/17160.37.0.1 to 160.37.127.254160.37.127.25532,766
76160.37.128.0/17160.37.128.1 to 160.37.255.254160.37.255.25532,766
77160.38.0.0/17160.38.0.1 to 160.38.127.254160.38.127.25532,766
78160.38.128.0/17160.38.128.1 to 160.38.255.254160.38.255.25532,766
79160.39.0.0/17160.39.0.1 to 160.39.127.254160.39.127.25532,766
80160.39.128.0/17160.39.128.1 to 160.39.255.254160.39.255.25532,766
81160.40.0.0/17160.40.0.1 to 160.40.127.254160.40.127.25532,766
82160.40.128.0/17160.40.128.1 to 160.40.255.254160.40.255.25532,766
83160.41.0.0/17160.41.0.1 to 160.41.127.254160.41.127.25532,766
84160.41.128.0/17160.41.128.1 to 160.41.255.254160.41.255.25532,766
85160.42.0.0/17160.42.0.1 to 160.42.127.254160.42.127.25532,766
86160.42.128.0/17160.42.128.1 to 160.42.255.254160.42.255.25532,766
87160.43.0.0/17160.43.0.1 to 160.43.127.254160.43.127.25532,766
88160.43.128.0/17160.43.128.1 to 160.43.255.254160.43.255.25532,766
89160.44.0.0/17160.44.0.1 to 160.44.127.254160.44.127.25532,766
90160.44.128.0/17160.44.128.1 to 160.44.255.254160.44.255.25532,766
91160.45.0.0/17160.45.0.1 to 160.45.127.254160.45.127.25532,766
92160.45.128.0/17160.45.128.1 to 160.45.255.254160.45.255.25532,766
93160.46.0.0/17160.46.0.1 to 160.46.127.254160.46.127.25532,766
94160.46.128.0/17160.46.128.1 to 160.46.255.254160.46.255.25532,766
95160.47.0.0/17160.47.0.1 to 160.47.127.254160.47.127.25532,766
96160.47.128.0/17160.47.128.1 to 160.47.255.254160.47.255.25532,766
97160.48.0.0/17160.48.0.1 to 160.48.127.254160.48.127.25532,766
98160.48.128.0/17160.48.128.1 to 160.48.255.254160.48.255.25532,766
99160.49.0.0/17160.49.0.1 to 160.49.127.254160.49.127.25532,766
100160.49.128.0/17160.49.128.1 to 160.49.255.254160.49.255.25532,766
101160.50.0.0/17160.50.0.1 to 160.50.127.254160.50.127.25532,766
102160.50.128.0/17160.50.128.1 to 160.50.255.254160.50.255.25532,766
103160.51.0.0/17160.51.0.1 to 160.51.127.254160.51.127.25532,766
104160.51.128.0/17160.51.128.1 to 160.51.255.254160.51.255.25532,766
105160.52.0.0/17160.52.0.1 to 160.52.127.254160.52.127.25532,766
106160.52.128.0/17160.52.128.1 to 160.52.255.254160.52.255.25532,766
107160.53.0.0/17160.53.0.1 to 160.53.127.254160.53.127.25532,766
108160.53.128.0/17160.53.128.1 to 160.53.255.254160.53.255.25532,766
109160.54.0.0/17160.54.0.1 to 160.54.127.254160.54.127.25532,766
110160.54.128.0/17160.54.128.1 to 160.54.255.254160.54.255.25532,766
111160.55.0.0/17160.55.0.1 to 160.55.127.254160.55.127.25532,766
112160.55.128.0/17160.55.128.1 to 160.55.255.254160.55.255.25532,766
113160.56.0.0/17160.56.0.1 to 160.56.127.254160.56.127.25532,766
114160.56.128.0/17160.56.128.1 to 160.56.255.254160.56.255.25532,766
115160.57.0.0/17160.57.0.1 to 160.57.127.254160.57.127.25532,766
116160.57.128.0/17160.57.128.1 to 160.57.255.254160.57.255.25532,766
117160.58.0.0/17160.58.0.1 to 160.58.127.254160.58.127.25532,766
118160.58.128.0/17160.58.128.1 to 160.58.255.254160.58.255.25532,766
119160.59.0.0/17160.59.0.1 to 160.59.127.254160.59.127.25532,766
120160.59.128.0/17160.59.128.1 to 160.59.255.254160.59.255.25532,766
121160.60.0.0/17160.60.0.1 to 160.60.127.254160.60.127.25532,766
122160.60.128.0/17160.60.128.1 to 160.60.255.254160.60.255.25532,766
123160.61.0.0/17160.61.0.1 to 160.61.127.254160.61.127.25532,766
124160.61.128.0/17160.61.128.1 to 160.61.255.254160.61.255.25532,766
125160.62.0.0/17160.62.0.1 to 160.62.127.254160.62.127.25532,766
126160.62.128.0/17160.62.128.1 to 160.62.255.254160.62.255.25532,766
127160.63.0.0/17160.63.0.1 to 160.63.127.254160.63.127.25532,766
128160.63.128.0/17160.63.128.1 to 160.63.255.254160.63.255.25532,766
129160.64.0.0/17160.64.0.1 to 160.64.127.254160.64.127.25532,766
130160.64.128.0/17160.64.128.1 to 160.64.255.254160.64.255.25532,766
131160.65.0.0/17160.65.0.1 to 160.65.127.254160.65.127.25532,766
132160.65.128.0/17160.65.128.1 to 160.65.255.254160.65.255.25532,766
133160.66.0.0/17160.66.0.1 to 160.66.127.254160.66.127.25532,766
134160.66.128.0/17160.66.128.1 to 160.66.255.254160.66.255.25532,766
135160.67.0.0/17160.67.0.1 to 160.67.127.254160.67.127.25532,766
136160.67.128.0/17160.67.128.1 to 160.67.255.254160.67.255.25532,766
137160.68.0.0/17160.68.0.1 to 160.68.127.254160.68.127.25532,766
138160.68.128.0/17160.68.128.1 to 160.68.255.254160.68.255.25532,766
139160.69.0.0/17160.69.0.1 to 160.69.127.254160.69.127.25532,766
140160.69.128.0/17160.69.128.1 to 160.69.255.254160.69.255.25532,766
141160.70.0.0/17160.70.0.1 to 160.70.127.254160.70.127.25532,766
142160.70.128.0/17160.70.128.1 to 160.70.255.254160.70.255.25532,766
143160.71.0.0/17160.71.0.1 to 160.71.127.254160.71.127.25532,766
144160.71.128.0/17160.71.128.1 to 160.71.255.254160.71.255.25532,766
145160.72.0.0/17160.72.0.1 to 160.72.127.254160.72.127.25532,766
146160.72.128.0/17160.72.128.1 to 160.72.255.254160.72.255.25532,766
147160.73.0.0/17160.73.0.1 to 160.73.127.254160.73.127.25532,766
148160.73.128.0/17160.73.128.1 to 160.73.255.254160.73.255.25532,766
149160.74.0.0/17160.74.0.1 to 160.74.127.254160.74.127.25532,766
150160.74.128.0/17160.74.128.1 to 160.74.255.254160.74.255.25532,766
151160.75.0.0/17160.75.0.1 to 160.75.127.254160.75.127.25532,766
152160.75.128.0/17160.75.128.1 to 160.75.255.254160.75.255.25532,766
153160.76.0.0/17160.76.0.1 to 160.76.127.254160.76.127.25532,766
154160.76.128.0/17160.76.128.1 to 160.76.255.254160.76.255.25532,766
155160.77.0.0/17160.77.0.1 to 160.77.127.254160.77.127.25532,766
156160.77.128.0/17160.77.128.1 to 160.77.255.254160.77.255.25532,766
157160.78.0.0/17160.78.0.1 to 160.78.127.254160.78.127.25532,766
158160.78.128.0/17160.78.128.1 to 160.78.255.254160.78.255.25532,766
159160.79.0.0/17160.79.0.1 to 160.79.127.254160.79.127.25532,766
160160.79.128.0/17160.79.128.1 to 160.79.255.254160.79.255.25532,766
161160.80.0.0/17160.80.0.1 to 160.80.127.254160.80.127.25532,766
162160.80.128.0/17160.80.128.1 to 160.80.255.254160.80.255.25532,766
163160.81.0.0/17160.81.0.1 to 160.81.127.254160.81.127.25532,766
164160.81.128.0/17160.81.128.1 to 160.81.255.254160.81.255.25532,766
165160.82.0.0/17160.82.0.1 to 160.82.127.254160.82.127.25532,766
166160.82.128.0/17160.82.128.1 to 160.82.255.254160.82.255.25532,766
167160.83.0.0/17160.83.0.1 to 160.83.127.254160.83.127.25532,766
168160.83.128.0/17160.83.128.1 to 160.83.255.254160.83.255.25532,766
169160.84.0.0/17160.84.0.1 to 160.84.127.254160.84.127.25532,766
170160.84.128.0/17160.84.128.1 to 160.84.255.254160.84.255.25532,766
171160.85.0.0/17160.85.0.1 to 160.85.127.254160.85.127.25532,766
172160.85.128.0/17160.85.128.1 to 160.85.255.254160.85.255.25532,766
173160.86.0.0/17160.86.0.1 to 160.86.127.254160.86.127.25532,766
174160.86.128.0/17160.86.128.1 to 160.86.255.254160.86.255.25532,766
175160.87.0.0/17160.87.0.1 to 160.87.127.254160.87.127.25532,766
176160.87.128.0/17160.87.128.1 to 160.87.255.254160.87.255.25532,766
177160.88.0.0/17160.88.0.1 to 160.88.127.254160.88.127.25532,766
178160.88.128.0/17160.88.128.1 to 160.88.255.254160.88.255.25532,766
179160.89.0.0/17160.89.0.1 to 160.89.127.254160.89.127.25532,766
180160.89.128.0/17160.89.128.1 to 160.89.255.254160.89.255.25532,766
181160.90.0.0/17160.90.0.1 to 160.90.127.254160.90.127.25532,766
182160.90.128.0/17160.90.128.1 to 160.90.255.254160.90.255.25532,766
183160.91.0.0/17160.91.0.1 to 160.91.127.254160.91.127.25532,766
184160.91.128.0/17160.91.128.1 to 160.91.255.254160.91.255.25532,766
185160.92.0.0/17160.92.0.1 to 160.92.127.254160.92.127.25532,766
186160.92.128.0/17160.92.128.1 to 160.92.255.254160.92.255.25532,766
187160.93.0.0/17160.93.0.1 to 160.93.127.254160.93.127.25532,766
188160.93.128.0/17160.93.128.1 to 160.93.255.254160.93.255.25532,766
189160.94.0.0/17160.94.0.1 to 160.94.127.254160.94.127.25532,766
190160.94.128.0/17160.94.128.1 to 160.94.255.254160.94.255.25532,766
191160.95.0.0/17160.95.0.1 to 160.95.127.254160.95.127.25532,766
192160.95.128.0/17160.95.128.1 to 160.95.255.254160.95.255.25532,766
193160.96.0.0/17160.96.0.1 to 160.96.127.254160.96.127.25532,766
194160.96.128.0/17160.96.128.1 to 160.96.255.254160.96.255.25532,766
195160.97.0.0/17160.97.0.1 to 160.97.127.254160.97.127.25532,766
196160.97.128.0/17160.97.128.1 to 160.97.255.254160.97.255.25532,766
197160.98.0.0/17160.98.0.1 to 160.98.127.254160.98.127.25532,766
198160.98.128.0/17160.98.128.1 to 160.98.255.254160.98.255.25532,766
199160.99.0.0/17160.99.0.1 to 160.99.127.254160.99.127.25532,766
200160.99.128.0/17160.99.128.1 to 160.99.255.254160.99.255.25532,766
201160.100.0.0/17160.100.0.1 to 160.100.127.254160.100.127.25532,766
202160.100.128.0/17160.100.128.1 to 160.100.255.254160.100.255.25532,766
203160.101.0.0/17160.101.0.1 to 160.101.127.254160.101.127.25532,766
204160.101.128.0/17160.101.128.1 to 160.101.255.254160.101.255.25532,766
205160.102.0.0/17160.102.0.1 to 160.102.127.254160.102.127.25532,766
206160.102.128.0/17160.102.128.1 to 160.102.255.254160.102.255.25532,766
207160.103.0.0/17160.103.0.1 to 160.103.127.254160.103.127.25532,766
208160.103.128.0/17160.103.128.1 to 160.103.255.254160.103.255.25532,766
209160.104.0.0/17160.104.0.1 to 160.104.127.254160.104.127.25532,766
210160.104.128.0/17160.104.128.1 to 160.104.255.254160.104.255.25532,766
211160.105.0.0/17160.105.0.1 to 160.105.127.254160.105.127.25532,766
212160.105.128.0/17160.105.128.1 to 160.105.255.254160.105.255.25532,766
213160.106.0.0/17160.106.0.1 to 160.106.127.254160.106.127.25532,766
214160.106.128.0/17160.106.128.1 to 160.106.255.254160.106.255.25532,766
215160.107.0.0/17160.107.0.1 to 160.107.127.254160.107.127.25532,766
216160.107.128.0/17160.107.128.1 to 160.107.255.254160.107.255.25532,766
217160.108.0.0/17160.108.0.1 to 160.108.127.254160.108.127.25532,766
218160.108.128.0/17160.108.128.1 to 160.108.255.254160.108.255.25532,766
219160.109.0.0/17160.109.0.1 to 160.109.127.254160.109.127.25532,766
220160.109.128.0/17160.109.128.1 to 160.109.255.254160.109.255.25532,766
221160.110.0.0/17160.110.0.1 to 160.110.127.254160.110.127.25532,766
222160.110.128.0/17160.110.128.1 to 160.110.255.254160.110.255.25532,766
223160.111.0.0/17160.111.0.1 to 160.111.127.254160.111.127.25532,766
224160.111.128.0/17160.111.128.1 to 160.111.255.254160.111.255.25532,766
225160.112.0.0/17160.112.0.1 to 160.112.127.254160.112.127.25532,766
226160.112.128.0/17160.112.128.1 to 160.112.255.254160.112.255.25532,766
227160.113.0.0/17160.113.0.1 to 160.113.127.254160.113.127.25532,766
228160.113.128.0/17160.113.128.1 to 160.113.255.254160.113.255.25532,766
229160.114.0.0/17160.114.0.1 to 160.114.127.254160.114.127.25532,766
230160.114.128.0/17160.114.128.1 to 160.114.255.254160.114.255.25532,766
231160.115.0.0/17160.115.0.1 to 160.115.127.254160.115.127.25532,766
232160.115.128.0/17160.115.128.1 to 160.115.255.254160.115.255.25532,766
233160.116.0.0/17160.116.0.1 to 160.116.127.254160.116.127.25532,766
234160.116.128.0/17160.116.128.1 to 160.116.255.254160.116.255.25532,766
235160.117.0.0/17160.117.0.1 to 160.117.127.254160.117.127.25532,766
236160.117.128.0/17160.117.128.1 to 160.117.255.254160.117.255.25532,766
237160.118.0.0/17160.118.0.1 to 160.118.127.254160.118.127.25532,766
238160.118.128.0/17160.118.128.1 to 160.118.255.254160.118.255.25532,766
239160.119.0.0/17160.119.0.1 to 160.119.127.254160.119.127.25532,766
240160.119.128.0/17160.119.128.1 to 160.119.255.254160.119.255.25532,766
241160.120.0.0/17160.120.0.1 to 160.120.127.254160.120.127.25532,766
242160.120.128.0/17160.120.128.1 to 160.120.255.254160.120.255.25532,766
243160.121.0.0/17160.121.0.1 to 160.121.127.254160.121.127.25532,766
244160.121.128.0/17160.121.128.1 to 160.121.255.254160.121.255.25532,766
245160.122.0.0/17160.122.0.1 to 160.122.127.254160.122.127.25532,766
246160.122.128.0/17160.122.128.1 to 160.122.255.254160.122.255.25532,766
247160.123.0.0/17160.123.0.1 to 160.123.127.254160.123.127.25532,766
248160.123.128.0/17160.123.128.1 to 160.123.255.254160.123.255.25532,766
249160.124.0.0/17160.124.0.1 to 160.124.127.254160.124.127.25532,766
250160.124.128.0/17160.124.128.1 to 160.124.255.254160.124.255.25532,766
251160.125.0.0/17160.125.0.1 to 160.125.127.254160.125.127.25532,766
252160.125.128.0/17160.125.128.1 to 160.125.255.254160.125.255.25532,766
253160.126.0.0/17160.126.0.1 to 160.126.127.254160.126.127.25532,766
254160.126.128.0/17160.126.128.1 to 160.126.255.254160.126.255.25532,766
255160.127.0.0/17160.127.0.1 to 160.127.127.254160.127.127.25532,766
256160.127.128.0/17160.127.128.1 to 160.127.255.254160.127.255.25532,766

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.