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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.

Network107.0.0.0/8
Usable hosts16,777,214
Subnet mask255.0.0.0
Addresses16,777,216
Network address
107.0.0.0
Broadcast address
107.255.255.255
First usable
107.0.0.1
Last usable
107.255.255.254
Usable hosts
16,777,214 (16,777,216 less the network and broadcast addresses)
Subnet mask
255.0.0.0
Wildcard mask
0.255.255.255 (Cisco ACLs, OSPF)
Prefix length
/8
Type
Public public
Old class
A (default /8)
As numbers
Hex 6B000000 · Integer 1795162112 to 1811939327
Reverse DNS zone
107.in-addr.arpa
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address01101011..00000000.00000000.00000000107.0.0.0
Subnet mask11111111..00000000.00000000.00000000255.0.0.0
Network01101011..00000000.00000000.00000000107.0.0.0
Broadcast01101011..11111111.11111111.11111111107.255.255.255
Split into smaller subnets/17
/9 (2)/10 (4)/11 (8)/12 (16)/13 (32)/14 (64)/15 (128)/16 (256)/17 (512)/18 (1,024)/19 (2,048)/20 (4,096)

107.0.0.0/8 makes 512 subnets of /17; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1107.0.0.0/17107.0.0.1 to 107.0.127.254107.0.127.25532,766
2107.0.128.0/17107.0.128.1 to 107.0.255.254107.0.255.25532,766
3107.1.0.0/17107.1.0.1 to 107.1.127.254107.1.127.25532,766
4107.1.128.0/17107.1.128.1 to 107.1.255.254107.1.255.25532,766
5107.2.0.0/17107.2.0.1 to 107.2.127.254107.2.127.25532,766
6107.2.128.0/17107.2.128.1 to 107.2.255.254107.2.255.25532,766
7107.3.0.0/17107.3.0.1 to 107.3.127.254107.3.127.25532,766
8107.3.128.0/17107.3.128.1 to 107.3.255.254107.3.255.25532,766
9107.4.0.0/17107.4.0.1 to 107.4.127.254107.4.127.25532,766
10107.4.128.0/17107.4.128.1 to 107.4.255.254107.4.255.25532,766
11107.5.0.0/17107.5.0.1 to 107.5.127.254107.5.127.25532,766
12107.5.128.0/17107.5.128.1 to 107.5.255.254107.5.255.25532,766
13107.6.0.0/17107.6.0.1 to 107.6.127.254107.6.127.25532,766
14107.6.128.0/17107.6.128.1 to 107.6.255.254107.6.255.25532,766
15107.7.0.0/17107.7.0.1 to 107.7.127.254107.7.127.25532,766
16107.7.128.0/17107.7.128.1 to 107.7.255.254107.7.255.25532,766
17107.8.0.0/17107.8.0.1 to 107.8.127.254107.8.127.25532,766
18107.8.128.0/17107.8.128.1 to 107.8.255.254107.8.255.25532,766
19107.9.0.0/17107.9.0.1 to 107.9.127.254107.9.127.25532,766
20107.9.128.0/17107.9.128.1 to 107.9.255.254107.9.255.25532,766
21107.10.0.0/17107.10.0.1 to 107.10.127.254107.10.127.25532,766
22107.10.128.0/17107.10.128.1 to 107.10.255.254107.10.255.25532,766
23107.11.0.0/17107.11.0.1 to 107.11.127.254107.11.127.25532,766
24107.11.128.0/17107.11.128.1 to 107.11.255.254107.11.255.25532,766
25107.12.0.0/17107.12.0.1 to 107.12.127.254107.12.127.25532,766
26107.12.128.0/17107.12.128.1 to 107.12.255.254107.12.255.25532,766
27107.13.0.0/17107.13.0.1 to 107.13.127.254107.13.127.25532,766
28107.13.128.0/17107.13.128.1 to 107.13.255.254107.13.255.25532,766
29107.14.0.0/17107.14.0.1 to 107.14.127.254107.14.127.25532,766
30107.14.128.0/17107.14.128.1 to 107.14.255.254107.14.255.25532,766
31107.15.0.0/17107.15.0.1 to 107.15.127.254107.15.127.25532,766
32107.15.128.0/17107.15.128.1 to 107.15.255.254107.15.255.25532,766
33107.16.0.0/17107.16.0.1 to 107.16.127.254107.16.127.25532,766
34107.16.128.0/17107.16.128.1 to 107.16.255.254107.16.255.25532,766
35107.17.0.0/17107.17.0.1 to 107.17.127.254107.17.127.25532,766
36107.17.128.0/17107.17.128.1 to 107.17.255.254107.17.255.25532,766
37107.18.0.0/17107.18.0.1 to 107.18.127.254107.18.127.25532,766
38107.18.128.0/17107.18.128.1 to 107.18.255.254107.18.255.25532,766
39107.19.0.0/17107.19.0.1 to 107.19.127.254107.19.127.25532,766
40107.19.128.0/17107.19.128.1 to 107.19.255.254107.19.255.25532,766
41107.20.0.0/17107.20.0.1 to 107.20.127.254107.20.127.25532,766
42107.20.128.0/17107.20.128.1 to 107.20.255.254107.20.255.25532,766
43107.21.0.0/17107.21.0.1 to 107.21.127.254107.21.127.25532,766
44107.21.128.0/17107.21.128.1 to 107.21.255.254107.21.255.25532,766
45107.22.0.0/17107.22.0.1 to 107.22.127.254107.22.127.25532,766
46107.22.128.0/17107.22.128.1 to 107.22.255.254107.22.255.25532,766
47107.23.0.0/17107.23.0.1 to 107.23.127.254107.23.127.25532,766
48107.23.128.0/17107.23.128.1 to 107.23.255.254107.23.255.25532,766
49107.24.0.0/17107.24.0.1 to 107.24.127.254107.24.127.25532,766
50107.24.128.0/17107.24.128.1 to 107.24.255.254107.24.255.25532,766
51107.25.0.0/17107.25.0.1 to 107.25.127.254107.25.127.25532,766
52107.25.128.0/17107.25.128.1 to 107.25.255.254107.25.255.25532,766
53107.26.0.0/17107.26.0.1 to 107.26.127.254107.26.127.25532,766
54107.26.128.0/17107.26.128.1 to 107.26.255.254107.26.255.25532,766
55107.27.0.0/17107.27.0.1 to 107.27.127.254107.27.127.25532,766
56107.27.128.0/17107.27.128.1 to 107.27.255.254107.27.255.25532,766
57107.28.0.0/17107.28.0.1 to 107.28.127.254107.28.127.25532,766
58107.28.128.0/17107.28.128.1 to 107.28.255.254107.28.255.25532,766
59107.29.0.0/17107.29.0.1 to 107.29.127.254107.29.127.25532,766
60107.29.128.0/17107.29.128.1 to 107.29.255.254107.29.255.25532,766
61107.30.0.0/17107.30.0.1 to 107.30.127.254107.30.127.25532,766
62107.30.128.0/17107.30.128.1 to 107.30.255.254107.30.255.25532,766
63107.31.0.0/17107.31.0.1 to 107.31.127.254107.31.127.25532,766
64107.31.128.0/17107.31.128.1 to 107.31.255.254107.31.255.25532,766
65107.32.0.0/17107.32.0.1 to 107.32.127.254107.32.127.25532,766
66107.32.128.0/17107.32.128.1 to 107.32.255.254107.32.255.25532,766
67107.33.0.0/17107.33.0.1 to 107.33.127.254107.33.127.25532,766
68107.33.128.0/17107.33.128.1 to 107.33.255.254107.33.255.25532,766
69107.34.0.0/17107.34.0.1 to 107.34.127.254107.34.127.25532,766
70107.34.128.0/17107.34.128.1 to 107.34.255.254107.34.255.25532,766
71107.35.0.0/17107.35.0.1 to 107.35.127.254107.35.127.25532,766
72107.35.128.0/17107.35.128.1 to 107.35.255.254107.35.255.25532,766
73107.36.0.0/17107.36.0.1 to 107.36.127.254107.36.127.25532,766
74107.36.128.0/17107.36.128.1 to 107.36.255.254107.36.255.25532,766
75107.37.0.0/17107.37.0.1 to 107.37.127.254107.37.127.25532,766
76107.37.128.0/17107.37.128.1 to 107.37.255.254107.37.255.25532,766
77107.38.0.0/17107.38.0.1 to 107.38.127.254107.38.127.25532,766
78107.38.128.0/17107.38.128.1 to 107.38.255.254107.38.255.25532,766
79107.39.0.0/17107.39.0.1 to 107.39.127.254107.39.127.25532,766
80107.39.128.0/17107.39.128.1 to 107.39.255.254107.39.255.25532,766
81107.40.0.0/17107.40.0.1 to 107.40.127.254107.40.127.25532,766
82107.40.128.0/17107.40.128.1 to 107.40.255.254107.40.255.25532,766
83107.41.0.0/17107.41.0.1 to 107.41.127.254107.41.127.25532,766
84107.41.128.0/17107.41.128.1 to 107.41.255.254107.41.255.25532,766
85107.42.0.0/17107.42.0.1 to 107.42.127.254107.42.127.25532,766
86107.42.128.0/17107.42.128.1 to 107.42.255.254107.42.255.25532,766
87107.43.0.0/17107.43.0.1 to 107.43.127.254107.43.127.25532,766
88107.43.128.0/17107.43.128.1 to 107.43.255.254107.43.255.25532,766
89107.44.0.0/17107.44.0.1 to 107.44.127.254107.44.127.25532,766
90107.44.128.0/17107.44.128.1 to 107.44.255.254107.44.255.25532,766
91107.45.0.0/17107.45.0.1 to 107.45.127.254107.45.127.25532,766
92107.45.128.0/17107.45.128.1 to 107.45.255.254107.45.255.25532,766
93107.46.0.0/17107.46.0.1 to 107.46.127.254107.46.127.25532,766
94107.46.128.0/17107.46.128.1 to 107.46.255.254107.46.255.25532,766
95107.47.0.0/17107.47.0.1 to 107.47.127.254107.47.127.25532,766
96107.47.128.0/17107.47.128.1 to 107.47.255.254107.47.255.25532,766
97107.48.0.0/17107.48.0.1 to 107.48.127.254107.48.127.25532,766
98107.48.128.0/17107.48.128.1 to 107.48.255.254107.48.255.25532,766
99107.49.0.0/17107.49.0.1 to 107.49.127.254107.49.127.25532,766
100107.49.128.0/17107.49.128.1 to 107.49.255.254107.49.255.25532,766
101107.50.0.0/17107.50.0.1 to 107.50.127.254107.50.127.25532,766
102107.50.128.0/17107.50.128.1 to 107.50.255.254107.50.255.25532,766
103107.51.0.0/17107.51.0.1 to 107.51.127.254107.51.127.25532,766
104107.51.128.0/17107.51.128.1 to 107.51.255.254107.51.255.25532,766
105107.52.0.0/17107.52.0.1 to 107.52.127.254107.52.127.25532,766
106107.52.128.0/17107.52.128.1 to 107.52.255.254107.52.255.25532,766
107107.53.0.0/17107.53.0.1 to 107.53.127.254107.53.127.25532,766
108107.53.128.0/17107.53.128.1 to 107.53.255.254107.53.255.25532,766
109107.54.0.0/17107.54.0.1 to 107.54.127.254107.54.127.25532,766
110107.54.128.0/17107.54.128.1 to 107.54.255.254107.54.255.25532,766
111107.55.0.0/17107.55.0.1 to 107.55.127.254107.55.127.25532,766
112107.55.128.0/17107.55.128.1 to 107.55.255.254107.55.255.25532,766
113107.56.0.0/17107.56.0.1 to 107.56.127.254107.56.127.25532,766
114107.56.128.0/17107.56.128.1 to 107.56.255.254107.56.255.25532,766
115107.57.0.0/17107.57.0.1 to 107.57.127.254107.57.127.25532,766
116107.57.128.0/17107.57.128.1 to 107.57.255.254107.57.255.25532,766
117107.58.0.0/17107.58.0.1 to 107.58.127.254107.58.127.25532,766
118107.58.128.0/17107.58.128.1 to 107.58.255.254107.58.255.25532,766
119107.59.0.0/17107.59.0.1 to 107.59.127.254107.59.127.25532,766
120107.59.128.0/17107.59.128.1 to 107.59.255.254107.59.255.25532,766
121107.60.0.0/17107.60.0.1 to 107.60.127.254107.60.127.25532,766
122107.60.128.0/17107.60.128.1 to 107.60.255.254107.60.255.25532,766
123107.61.0.0/17107.61.0.1 to 107.61.127.254107.61.127.25532,766
124107.61.128.0/17107.61.128.1 to 107.61.255.254107.61.255.25532,766
125107.62.0.0/17107.62.0.1 to 107.62.127.254107.62.127.25532,766
126107.62.128.0/17107.62.128.1 to 107.62.255.254107.62.255.25532,766
127107.63.0.0/17107.63.0.1 to 107.63.127.254107.63.127.25532,766
128107.63.128.0/17107.63.128.1 to 107.63.255.254107.63.255.25532,766
129107.64.0.0/17107.64.0.1 to 107.64.127.254107.64.127.25532,766
130107.64.128.0/17107.64.128.1 to 107.64.255.254107.64.255.25532,766
131107.65.0.0/17107.65.0.1 to 107.65.127.254107.65.127.25532,766
132107.65.128.0/17107.65.128.1 to 107.65.255.254107.65.255.25532,766
133107.66.0.0/17107.66.0.1 to 107.66.127.254107.66.127.25532,766
134107.66.128.0/17107.66.128.1 to 107.66.255.254107.66.255.25532,766
135107.67.0.0/17107.67.0.1 to 107.67.127.254107.67.127.25532,766
136107.67.128.0/17107.67.128.1 to 107.67.255.254107.67.255.25532,766
137107.68.0.0/17107.68.0.1 to 107.68.127.254107.68.127.25532,766
138107.68.128.0/17107.68.128.1 to 107.68.255.254107.68.255.25532,766
139107.69.0.0/17107.69.0.1 to 107.69.127.254107.69.127.25532,766
140107.69.128.0/17107.69.128.1 to 107.69.255.254107.69.255.25532,766
141107.70.0.0/17107.70.0.1 to 107.70.127.254107.70.127.25532,766
142107.70.128.0/17107.70.128.1 to 107.70.255.254107.70.255.25532,766
143107.71.0.0/17107.71.0.1 to 107.71.127.254107.71.127.25532,766
144107.71.128.0/17107.71.128.1 to 107.71.255.254107.71.255.25532,766
145107.72.0.0/17107.72.0.1 to 107.72.127.254107.72.127.25532,766
146107.72.128.0/17107.72.128.1 to 107.72.255.254107.72.255.25532,766
147107.73.0.0/17107.73.0.1 to 107.73.127.254107.73.127.25532,766
148107.73.128.0/17107.73.128.1 to 107.73.255.254107.73.255.25532,766
149107.74.0.0/17107.74.0.1 to 107.74.127.254107.74.127.25532,766
150107.74.128.0/17107.74.128.1 to 107.74.255.254107.74.255.25532,766
151107.75.0.0/17107.75.0.1 to 107.75.127.254107.75.127.25532,766
152107.75.128.0/17107.75.128.1 to 107.75.255.254107.75.255.25532,766
153107.76.0.0/17107.76.0.1 to 107.76.127.254107.76.127.25532,766
154107.76.128.0/17107.76.128.1 to 107.76.255.254107.76.255.25532,766
155107.77.0.0/17107.77.0.1 to 107.77.127.254107.77.127.25532,766
156107.77.128.0/17107.77.128.1 to 107.77.255.254107.77.255.25532,766
157107.78.0.0/17107.78.0.1 to 107.78.127.254107.78.127.25532,766
158107.78.128.0/17107.78.128.1 to 107.78.255.254107.78.255.25532,766
159107.79.0.0/17107.79.0.1 to 107.79.127.254107.79.127.25532,766
160107.79.128.0/17107.79.128.1 to 107.79.255.254107.79.255.25532,766
161107.80.0.0/17107.80.0.1 to 107.80.127.254107.80.127.25532,766
162107.80.128.0/17107.80.128.1 to 107.80.255.254107.80.255.25532,766
163107.81.0.0/17107.81.0.1 to 107.81.127.254107.81.127.25532,766
164107.81.128.0/17107.81.128.1 to 107.81.255.254107.81.255.25532,766
165107.82.0.0/17107.82.0.1 to 107.82.127.254107.82.127.25532,766
166107.82.128.0/17107.82.128.1 to 107.82.255.254107.82.255.25532,766
167107.83.0.0/17107.83.0.1 to 107.83.127.254107.83.127.25532,766
168107.83.128.0/17107.83.128.1 to 107.83.255.254107.83.255.25532,766
169107.84.0.0/17107.84.0.1 to 107.84.127.254107.84.127.25532,766
170107.84.128.0/17107.84.128.1 to 107.84.255.254107.84.255.25532,766
171107.85.0.0/17107.85.0.1 to 107.85.127.254107.85.127.25532,766
172107.85.128.0/17107.85.128.1 to 107.85.255.254107.85.255.25532,766
173107.86.0.0/17107.86.0.1 to 107.86.127.254107.86.127.25532,766
174107.86.128.0/17107.86.128.1 to 107.86.255.254107.86.255.25532,766
175107.87.0.0/17107.87.0.1 to 107.87.127.254107.87.127.25532,766
176107.87.128.0/17107.87.128.1 to 107.87.255.254107.87.255.25532,766
177107.88.0.0/17107.88.0.1 to 107.88.127.254107.88.127.25532,766
178107.88.128.0/17107.88.128.1 to 107.88.255.254107.88.255.25532,766
179107.89.0.0/17107.89.0.1 to 107.89.127.254107.89.127.25532,766
180107.89.128.0/17107.89.128.1 to 107.89.255.254107.89.255.25532,766
181107.90.0.0/17107.90.0.1 to 107.90.127.254107.90.127.25532,766
182107.90.128.0/17107.90.128.1 to 107.90.255.254107.90.255.25532,766
183107.91.0.0/17107.91.0.1 to 107.91.127.254107.91.127.25532,766
184107.91.128.0/17107.91.128.1 to 107.91.255.254107.91.255.25532,766
185107.92.0.0/17107.92.0.1 to 107.92.127.254107.92.127.25532,766
186107.92.128.0/17107.92.128.1 to 107.92.255.254107.92.255.25532,766
187107.93.0.0/17107.93.0.1 to 107.93.127.254107.93.127.25532,766
188107.93.128.0/17107.93.128.1 to 107.93.255.254107.93.255.25532,766
189107.94.0.0/17107.94.0.1 to 107.94.127.254107.94.127.25532,766
190107.94.128.0/17107.94.128.1 to 107.94.255.254107.94.255.25532,766
191107.95.0.0/17107.95.0.1 to 107.95.127.254107.95.127.25532,766
192107.95.128.0/17107.95.128.1 to 107.95.255.254107.95.255.25532,766
193107.96.0.0/17107.96.0.1 to 107.96.127.254107.96.127.25532,766
194107.96.128.0/17107.96.128.1 to 107.96.255.254107.96.255.25532,766
195107.97.0.0/17107.97.0.1 to 107.97.127.254107.97.127.25532,766
196107.97.128.0/17107.97.128.1 to 107.97.255.254107.97.255.25532,766
197107.98.0.0/17107.98.0.1 to 107.98.127.254107.98.127.25532,766
198107.98.128.0/17107.98.128.1 to 107.98.255.254107.98.255.25532,766
199107.99.0.0/17107.99.0.1 to 107.99.127.254107.99.127.25532,766
200107.99.128.0/17107.99.128.1 to 107.99.255.254107.99.255.25532,766
201107.100.0.0/17107.100.0.1 to 107.100.127.254107.100.127.25532,766
202107.100.128.0/17107.100.128.1 to 107.100.255.254107.100.255.25532,766
203107.101.0.0/17107.101.0.1 to 107.101.127.254107.101.127.25532,766
204107.101.128.0/17107.101.128.1 to 107.101.255.254107.101.255.25532,766
205107.102.0.0/17107.102.0.1 to 107.102.127.254107.102.127.25532,766
206107.102.128.0/17107.102.128.1 to 107.102.255.254107.102.255.25532,766
207107.103.0.0/17107.103.0.1 to 107.103.127.254107.103.127.25532,766
208107.103.128.0/17107.103.128.1 to 107.103.255.254107.103.255.25532,766
209107.104.0.0/17107.104.0.1 to 107.104.127.254107.104.127.25532,766
210107.104.128.0/17107.104.128.1 to 107.104.255.254107.104.255.25532,766
211107.105.0.0/17107.105.0.1 to 107.105.127.254107.105.127.25532,766
212107.105.128.0/17107.105.128.1 to 107.105.255.254107.105.255.25532,766
213107.106.0.0/17107.106.0.1 to 107.106.127.254107.106.127.25532,766
214107.106.128.0/17107.106.128.1 to 107.106.255.254107.106.255.25532,766
215107.107.0.0/17107.107.0.1 to 107.107.127.254107.107.127.25532,766
216107.107.128.0/17107.107.128.1 to 107.107.255.254107.107.255.25532,766
217107.108.0.0/17107.108.0.1 to 107.108.127.254107.108.127.25532,766
218107.108.128.0/17107.108.128.1 to 107.108.255.254107.108.255.25532,766
219107.109.0.0/17107.109.0.1 to 107.109.127.254107.109.127.25532,766
220107.109.128.0/17107.109.128.1 to 107.109.255.254107.109.255.25532,766
221107.110.0.0/17107.110.0.1 to 107.110.127.254107.110.127.25532,766
222107.110.128.0/17107.110.128.1 to 107.110.255.254107.110.255.25532,766
223107.111.0.0/17107.111.0.1 to 107.111.127.254107.111.127.25532,766
224107.111.128.0/17107.111.128.1 to 107.111.255.254107.111.255.25532,766
225107.112.0.0/17107.112.0.1 to 107.112.127.254107.112.127.25532,766
226107.112.128.0/17107.112.128.1 to 107.112.255.254107.112.255.25532,766
227107.113.0.0/17107.113.0.1 to 107.113.127.254107.113.127.25532,766
228107.113.128.0/17107.113.128.1 to 107.113.255.254107.113.255.25532,766
229107.114.0.0/17107.114.0.1 to 107.114.127.254107.114.127.25532,766
230107.114.128.0/17107.114.128.1 to 107.114.255.254107.114.255.25532,766
231107.115.0.0/17107.115.0.1 to 107.115.127.254107.115.127.25532,766
232107.115.128.0/17107.115.128.1 to 107.115.255.254107.115.255.25532,766
233107.116.0.0/17107.116.0.1 to 107.116.127.254107.116.127.25532,766
234107.116.128.0/17107.116.128.1 to 107.116.255.254107.116.255.25532,766
235107.117.0.0/17107.117.0.1 to 107.117.127.254107.117.127.25532,766
236107.117.128.0/17107.117.128.1 to 107.117.255.254107.117.255.25532,766
237107.118.0.0/17107.118.0.1 to 107.118.127.254107.118.127.25532,766
238107.118.128.0/17107.118.128.1 to 107.118.255.254107.118.255.25532,766
239107.119.0.0/17107.119.0.1 to 107.119.127.254107.119.127.25532,766
240107.119.128.0/17107.119.128.1 to 107.119.255.254107.119.255.25532,766
241107.120.0.0/17107.120.0.1 to 107.120.127.254107.120.127.25532,766
242107.120.128.0/17107.120.128.1 to 107.120.255.254107.120.255.25532,766
243107.121.0.0/17107.121.0.1 to 107.121.127.254107.121.127.25532,766
244107.121.128.0/17107.121.128.1 to 107.121.255.254107.121.255.25532,766
245107.122.0.0/17107.122.0.1 to 107.122.127.254107.122.127.25532,766
246107.122.128.0/17107.122.128.1 to 107.122.255.254107.122.255.25532,766
247107.123.0.0/17107.123.0.1 to 107.123.127.254107.123.127.25532,766
248107.123.128.0/17107.123.128.1 to 107.123.255.254107.123.255.25532,766
249107.124.0.0/17107.124.0.1 to 107.124.127.254107.124.127.25532,766
250107.124.128.0/17107.124.128.1 to 107.124.255.254107.124.255.25532,766
251107.125.0.0/17107.125.0.1 to 107.125.127.254107.125.127.25532,766
252107.125.128.0/17107.125.128.1 to 107.125.255.254107.125.255.25532,766
253107.126.0.0/17107.126.0.1 to 107.126.127.254107.126.127.25532,766
254107.126.128.0/17107.126.128.1 to 107.126.255.254107.126.255.25532,766
255107.127.0.0/17107.127.0.1 to 107.127.127.254107.127.127.25532,766
256107.127.128.0/17107.127.128.1 to 107.127.255.254107.127.255.25532,766

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.