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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.

Network113.78.0.0/15
Usable hosts131,070
Subnet mask255.254.0.0
Addresses131,072
Network address
113.78.0.0
Broadcast address
113.79.255.255
First usable
113.78.0.1
Last usable
113.79.255.254
Usable hosts
131,070 (131,072 less the network and broadcast addresses)
Subnet mask
255.254.0.0
Wildcard mask
0.1.255.255 (Cisco ACLs, OSPF)
Prefix length
/15
Type
Public public
Old class
A (default /8)
As numbers
Hex 714E0000 · Integer 1900937216 to 1901068287
Reverse DNS zones
78.113.in-addr.arpa
79.113.in-addr.arpa
/15 is not on a 8-bit boundary, so it takes 2 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address01110001.01001110.00000000.00000000113.78.0.0
Subnet mask11111111.11111110.00000000.00000000255.254.0.0
Network01110001.01001110.00000000.00000000113.78.0.0
Broadcast01110001.01001111.11111111.11111111113.79.255.255
Split into smaller subnets/24
/16 (2)/17 (4)/18 (8)/19 (16)/20 (32)/21 (64)/22 (128)/23 (256)/24 (512)/25 (1,024)/26 (2,048)/27 (4,096)

113.78.0.0/15 makes 512 subnets of /24; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1113.78.0.0/24113.78.0.1 to 113.78.0.254113.78.0.255254
2113.78.1.0/24113.78.1.1 to 113.78.1.254113.78.1.255254
3113.78.2.0/24113.78.2.1 to 113.78.2.254113.78.2.255254
4113.78.3.0/24113.78.3.1 to 113.78.3.254113.78.3.255254
5113.78.4.0/24113.78.4.1 to 113.78.4.254113.78.4.255254
6113.78.5.0/24113.78.5.1 to 113.78.5.254113.78.5.255254
7113.78.6.0/24113.78.6.1 to 113.78.6.254113.78.6.255254
8113.78.7.0/24113.78.7.1 to 113.78.7.254113.78.7.255254
9113.78.8.0/24113.78.8.1 to 113.78.8.254113.78.8.255254
10113.78.9.0/24113.78.9.1 to 113.78.9.254113.78.9.255254
11113.78.10.0/24113.78.10.1 to 113.78.10.254113.78.10.255254
12113.78.11.0/24113.78.11.1 to 113.78.11.254113.78.11.255254
13113.78.12.0/24113.78.12.1 to 113.78.12.254113.78.12.255254
14113.78.13.0/24113.78.13.1 to 113.78.13.254113.78.13.255254
15113.78.14.0/24113.78.14.1 to 113.78.14.254113.78.14.255254
16113.78.15.0/24113.78.15.1 to 113.78.15.254113.78.15.255254
17113.78.16.0/24113.78.16.1 to 113.78.16.254113.78.16.255254
18113.78.17.0/24113.78.17.1 to 113.78.17.254113.78.17.255254
19113.78.18.0/24113.78.18.1 to 113.78.18.254113.78.18.255254
20113.78.19.0/24113.78.19.1 to 113.78.19.254113.78.19.255254
21113.78.20.0/24113.78.20.1 to 113.78.20.254113.78.20.255254
22113.78.21.0/24113.78.21.1 to 113.78.21.254113.78.21.255254
23113.78.22.0/24113.78.22.1 to 113.78.22.254113.78.22.255254
24113.78.23.0/24113.78.23.1 to 113.78.23.254113.78.23.255254
25113.78.24.0/24113.78.24.1 to 113.78.24.254113.78.24.255254
26113.78.25.0/24113.78.25.1 to 113.78.25.254113.78.25.255254
27113.78.26.0/24113.78.26.1 to 113.78.26.254113.78.26.255254
28113.78.27.0/24113.78.27.1 to 113.78.27.254113.78.27.255254
29113.78.28.0/24113.78.28.1 to 113.78.28.254113.78.28.255254
30113.78.29.0/24113.78.29.1 to 113.78.29.254113.78.29.255254
31113.78.30.0/24113.78.30.1 to 113.78.30.254113.78.30.255254
32113.78.31.0/24113.78.31.1 to 113.78.31.254113.78.31.255254
33113.78.32.0/24113.78.32.1 to 113.78.32.254113.78.32.255254
34113.78.33.0/24113.78.33.1 to 113.78.33.254113.78.33.255254
35113.78.34.0/24113.78.34.1 to 113.78.34.254113.78.34.255254
36113.78.35.0/24113.78.35.1 to 113.78.35.254113.78.35.255254
37113.78.36.0/24113.78.36.1 to 113.78.36.254113.78.36.255254
38113.78.37.0/24113.78.37.1 to 113.78.37.254113.78.37.255254
39113.78.38.0/24113.78.38.1 to 113.78.38.254113.78.38.255254
40113.78.39.0/24113.78.39.1 to 113.78.39.254113.78.39.255254
41113.78.40.0/24113.78.40.1 to 113.78.40.254113.78.40.255254
42113.78.41.0/24113.78.41.1 to 113.78.41.254113.78.41.255254
43113.78.42.0/24113.78.42.1 to 113.78.42.254113.78.42.255254
44113.78.43.0/24113.78.43.1 to 113.78.43.254113.78.43.255254
45113.78.44.0/24113.78.44.1 to 113.78.44.254113.78.44.255254
46113.78.45.0/24113.78.45.1 to 113.78.45.254113.78.45.255254
47113.78.46.0/24113.78.46.1 to 113.78.46.254113.78.46.255254
48113.78.47.0/24113.78.47.1 to 113.78.47.254113.78.47.255254
49113.78.48.0/24113.78.48.1 to 113.78.48.254113.78.48.255254
50113.78.49.0/24113.78.49.1 to 113.78.49.254113.78.49.255254
51113.78.50.0/24113.78.50.1 to 113.78.50.254113.78.50.255254
52113.78.51.0/24113.78.51.1 to 113.78.51.254113.78.51.255254
53113.78.52.0/24113.78.52.1 to 113.78.52.254113.78.52.255254
54113.78.53.0/24113.78.53.1 to 113.78.53.254113.78.53.255254
55113.78.54.0/24113.78.54.1 to 113.78.54.254113.78.54.255254
56113.78.55.0/24113.78.55.1 to 113.78.55.254113.78.55.255254
57113.78.56.0/24113.78.56.1 to 113.78.56.254113.78.56.255254
58113.78.57.0/24113.78.57.1 to 113.78.57.254113.78.57.255254
59113.78.58.0/24113.78.58.1 to 113.78.58.254113.78.58.255254
60113.78.59.0/24113.78.59.1 to 113.78.59.254113.78.59.255254
61113.78.60.0/24113.78.60.1 to 113.78.60.254113.78.60.255254
62113.78.61.0/24113.78.61.1 to 113.78.61.254113.78.61.255254
63113.78.62.0/24113.78.62.1 to 113.78.62.254113.78.62.255254
64113.78.63.0/24113.78.63.1 to 113.78.63.254113.78.63.255254
65113.78.64.0/24113.78.64.1 to 113.78.64.254113.78.64.255254
66113.78.65.0/24113.78.65.1 to 113.78.65.254113.78.65.255254
67113.78.66.0/24113.78.66.1 to 113.78.66.254113.78.66.255254
68113.78.67.0/24113.78.67.1 to 113.78.67.254113.78.67.255254
69113.78.68.0/24113.78.68.1 to 113.78.68.254113.78.68.255254
70113.78.69.0/24113.78.69.1 to 113.78.69.254113.78.69.255254
71113.78.70.0/24113.78.70.1 to 113.78.70.254113.78.70.255254
72113.78.71.0/24113.78.71.1 to 113.78.71.254113.78.71.255254
73113.78.72.0/24113.78.72.1 to 113.78.72.254113.78.72.255254
74113.78.73.0/24113.78.73.1 to 113.78.73.254113.78.73.255254
75113.78.74.0/24113.78.74.1 to 113.78.74.254113.78.74.255254
76113.78.75.0/24113.78.75.1 to 113.78.75.254113.78.75.255254
77113.78.76.0/24113.78.76.1 to 113.78.76.254113.78.76.255254
78113.78.77.0/24113.78.77.1 to 113.78.77.254113.78.77.255254
79113.78.78.0/24113.78.78.1 to 113.78.78.254113.78.78.255254
80113.78.79.0/24113.78.79.1 to 113.78.79.254113.78.79.255254
81113.78.80.0/24113.78.80.1 to 113.78.80.254113.78.80.255254
82113.78.81.0/24113.78.81.1 to 113.78.81.254113.78.81.255254
83113.78.82.0/24113.78.82.1 to 113.78.82.254113.78.82.255254
84113.78.83.0/24113.78.83.1 to 113.78.83.254113.78.83.255254
85113.78.84.0/24113.78.84.1 to 113.78.84.254113.78.84.255254
86113.78.85.0/24113.78.85.1 to 113.78.85.254113.78.85.255254
87113.78.86.0/24113.78.86.1 to 113.78.86.254113.78.86.255254
88113.78.87.0/24113.78.87.1 to 113.78.87.254113.78.87.255254
89113.78.88.0/24113.78.88.1 to 113.78.88.254113.78.88.255254
90113.78.89.0/24113.78.89.1 to 113.78.89.254113.78.89.255254
91113.78.90.0/24113.78.90.1 to 113.78.90.254113.78.90.255254
92113.78.91.0/24113.78.91.1 to 113.78.91.254113.78.91.255254
93113.78.92.0/24113.78.92.1 to 113.78.92.254113.78.92.255254
94113.78.93.0/24113.78.93.1 to 113.78.93.254113.78.93.255254
95113.78.94.0/24113.78.94.1 to 113.78.94.254113.78.94.255254
96113.78.95.0/24113.78.95.1 to 113.78.95.254113.78.95.255254
97113.78.96.0/24113.78.96.1 to 113.78.96.254113.78.96.255254
98113.78.97.0/24113.78.97.1 to 113.78.97.254113.78.97.255254
99113.78.98.0/24113.78.98.1 to 113.78.98.254113.78.98.255254
100113.78.99.0/24113.78.99.1 to 113.78.99.254113.78.99.255254
101113.78.100.0/24113.78.100.1 to 113.78.100.254113.78.100.255254
102113.78.101.0/24113.78.101.1 to 113.78.101.254113.78.101.255254
103113.78.102.0/24113.78.102.1 to 113.78.102.254113.78.102.255254
104113.78.103.0/24113.78.103.1 to 113.78.103.254113.78.103.255254
105113.78.104.0/24113.78.104.1 to 113.78.104.254113.78.104.255254
106113.78.105.0/24113.78.105.1 to 113.78.105.254113.78.105.255254
107113.78.106.0/24113.78.106.1 to 113.78.106.254113.78.106.255254
108113.78.107.0/24113.78.107.1 to 113.78.107.254113.78.107.255254
109113.78.108.0/24113.78.108.1 to 113.78.108.254113.78.108.255254
110113.78.109.0/24113.78.109.1 to 113.78.109.254113.78.109.255254
111113.78.110.0/24113.78.110.1 to 113.78.110.254113.78.110.255254
112113.78.111.0/24113.78.111.1 to 113.78.111.254113.78.111.255254
113113.78.112.0/24113.78.112.1 to 113.78.112.254113.78.112.255254
114113.78.113.0/24113.78.113.1 to 113.78.113.254113.78.113.255254
115113.78.114.0/24113.78.114.1 to 113.78.114.254113.78.114.255254
116113.78.115.0/24113.78.115.1 to 113.78.115.254113.78.115.255254
117113.78.116.0/24113.78.116.1 to 113.78.116.254113.78.116.255254
118113.78.117.0/24113.78.117.1 to 113.78.117.254113.78.117.255254
119113.78.118.0/24113.78.118.1 to 113.78.118.254113.78.118.255254
120113.78.119.0/24113.78.119.1 to 113.78.119.254113.78.119.255254
121113.78.120.0/24113.78.120.1 to 113.78.120.254113.78.120.255254
122113.78.121.0/24113.78.121.1 to 113.78.121.254113.78.121.255254
123113.78.122.0/24113.78.122.1 to 113.78.122.254113.78.122.255254
124113.78.123.0/24113.78.123.1 to 113.78.123.254113.78.123.255254
125113.78.124.0/24113.78.124.1 to 113.78.124.254113.78.124.255254
126113.78.125.0/24113.78.125.1 to 113.78.125.254113.78.125.255254
127113.78.126.0/24113.78.126.1 to 113.78.126.254113.78.126.255254
128113.78.127.0/24113.78.127.1 to 113.78.127.254113.78.127.255254
129113.78.128.0/24113.78.128.1 to 113.78.128.254113.78.128.255254
130113.78.129.0/24113.78.129.1 to 113.78.129.254113.78.129.255254
131113.78.130.0/24113.78.130.1 to 113.78.130.254113.78.130.255254
132113.78.131.0/24113.78.131.1 to 113.78.131.254113.78.131.255254
133113.78.132.0/24113.78.132.1 to 113.78.132.254113.78.132.255254
134113.78.133.0/24113.78.133.1 to 113.78.133.254113.78.133.255254
135113.78.134.0/24113.78.134.1 to 113.78.134.254113.78.134.255254
136113.78.135.0/24113.78.135.1 to 113.78.135.254113.78.135.255254
137113.78.136.0/24113.78.136.1 to 113.78.136.254113.78.136.255254
138113.78.137.0/24113.78.137.1 to 113.78.137.254113.78.137.255254
139113.78.138.0/24113.78.138.1 to 113.78.138.254113.78.138.255254
140113.78.139.0/24113.78.139.1 to 113.78.139.254113.78.139.255254
141113.78.140.0/24113.78.140.1 to 113.78.140.254113.78.140.255254
142113.78.141.0/24113.78.141.1 to 113.78.141.254113.78.141.255254
143113.78.142.0/24113.78.142.1 to 113.78.142.254113.78.142.255254
144113.78.143.0/24113.78.143.1 to 113.78.143.254113.78.143.255254
145113.78.144.0/24113.78.144.1 to 113.78.144.254113.78.144.255254
146113.78.145.0/24113.78.145.1 to 113.78.145.254113.78.145.255254
147113.78.146.0/24113.78.146.1 to 113.78.146.254113.78.146.255254
148113.78.147.0/24113.78.147.1 to 113.78.147.254113.78.147.255254
149113.78.148.0/24113.78.148.1 to 113.78.148.254113.78.148.255254
150113.78.149.0/24113.78.149.1 to 113.78.149.254113.78.149.255254
151113.78.150.0/24113.78.150.1 to 113.78.150.254113.78.150.255254
152113.78.151.0/24113.78.151.1 to 113.78.151.254113.78.151.255254
153113.78.152.0/24113.78.152.1 to 113.78.152.254113.78.152.255254
154113.78.153.0/24113.78.153.1 to 113.78.153.254113.78.153.255254
155113.78.154.0/24113.78.154.1 to 113.78.154.254113.78.154.255254
156113.78.155.0/24113.78.155.1 to 113.78.155.254113.78.155.255254
157113.78.156.0/24113.78.156.1 to 113.78.156.254113.78.156.255254
158113.78.157.0/24113.78.157.1 to 113.78.157.254113.78.157.255254
159113.78.158.0/24113.78.158.1 to 113.78.158.254113.78.158.255254
160113.78.159.0/24113.78.159.1 to 113.78.159.254113.78.159.255254
161113.78.160.0/24113.78.160.1 to 113.78.160.254113.78.160.255254
162113.78.161.0/24113.78.161.1 to 113.78.161.254113.78.161.255254
163113.78.162.0/24113.78.162.1 to 113.78.162.254113.78.162.255254
164113.78.163.0/24113.78.163.1 to 113.78.163.254113.78.163.255254
165113.78.164.0/24113.78.164.1 to 113.78.164.254113.78.164.255254
166113.78.165.0/24113.78.165.1 to 113.78.165.254113.78.165.255254
167113.78.166.0/24113.78.166.1 to 113.78.166.254113.78.166.255254
168113.78.167.0/24113.78.167.1 to 113.78.167.254113.78.167.255254
169113.78.168.0/24113.78.168.1 to 113.78.168.254113.78.168.255254
170113.78.169.0/24113.78.169.1 to 113.78.169.254113.78.169.255254
171113.78.170.0/24113.78.170.1 to 113.78.170.254113.78.170.255254
172113.78.171.0/24113.78.171.1 to 113.78.171.254113.78.171.255254
173113.78.172.0/24113.78.172.1 to 113.78.172.254113.78.172.255254
174113.78.173.0/24113.78.173.1 to 113.78.173.254113.78.173.255254
175113.78.174.0/24113.78.174.1 to 113.78.174.254113.78.174.255254
176113.78.175.0/24113.78.175.1 to 113.78.175.254113.78.175.255254
177113.78.176.0/24113.78.176.1 to 113.78.176.254113.78.176.255254
178113.78.177.0/24113.78.177.1 to 113.78.177.254113.78.177.255254
179113.78.178.0/24113.78.178.1 to 113.78.178.254113.78.178.255254
180113.78.179.0/24113.78.179.1 to 113.78.179.254113.78.179.255254
181113.78.180.0/24113.78.180.1 to 113.78.180.254113.78.180.255254
182113.78.181.0/24113.78.181.1 to 113.78.181.254113.78.181.255254
183113.78.182.0/24113.78.182.1 to 113.78.182.254113.78.182.255254
184113.78.183.0/24113.78.183.1 to 113.78.183.254113.78.183.255254
185113.78.184.0/24113.78.184.1 to 113.78.184.254113.78.184.255254
186113.78.185.0/24113.78.185.1 to 113.78.185.254113.78.185.255254
187113.78.186.0/24113.78.186.1 to 113.78.186.254113.78.186.255254
188113.78.187.0/24113.78.187.1 to 113.78.187.254113.78.187.255254
189113.78.188.0/24113.78.188.1 to 113.78.188.254113.78.188.255254
190113.78.189.0/24113.78.189.1 to 113.78.189.254113.78.189.255254
191113.78.190.0/24113.78.190.1 to 113.78.190.254113.78.190.255254
192113.78.191.0/24113.78.191.1 to 113.78.191.254113.78.191.255254
193113.78.192.0/24113.78.192.1 to 113.78.192.254113.78.192.255254
194113.78.193.0/24113.78.193.1 to 113.78.193.254113.78.193.255254
195113.78.194.0/24113.78.194.1 to 113.78.194.254113.78.194.255254
196113.78.195.0/24113.78.195.1 to 113.78.195.254113.78.195.255254
197113.78.196.0/24113.78.196.1 to 113.78.196.254113.78.196.255254
198113.78.197.0/24113.78.197.1 to 113.78.197.254113.78.197.255254
199113.78.198.0/24113.78.198.1 to 113.78.198.254113.78.198.255254
200113.78.199.0/24113.78.199.1 to 113.78.199.254113.78.199.255254
201113.78.200.0/24113.78.200.1 to 113.78.200.254113.78.200.255254
202113.78.201.0/24113.78.201.1 to 113.78.201.254113.78.201.255254
203113.78.202.0/24113.78.202.1 to 113.78.202.254113.78.202.255254
204113.78.203.0/24113.78.203.1 to 113.78.203.254113.78.203.255254
205113.78.204.0/24113.78.204.1 to 113.78.204.254113.78.204.255254
206113.78.205.0/24113.78.205.1 to 113.78.205.254113.78.205.255254
207113.78.206.0/24113.78.206.1 to 113.78.206.254113.78.206.255254
208113.78.207.0/24113.78.207.1 to 113.78.207.254113.78.207.255254
209113.78.208.0/24113.78.208.1 to 113.78.208.254113.78.208.255254
210113.78.209.0/24113.78.209.1 to 113.78.209.254113.78.209.255254
211113.78.210.0/24113.78.210.1 to 113.78.210.254113.78.210.255254
212113.78.211.0/24113.78.211.1 to 113.78.211.254113.78.211.255254
213113.78.212.0/24113.78.212.1 to 113.78.212.254113.78.212.255254
214113.78.213.0/24113.78.213.1 to 113.78.213.254113.78.213.255254
215113.78.214.0/24113.78.214.1 to 113.78.214.254113.78.214.255254
216113.78.215.0/24113.78.215.1 to 113.78.215.254113.78.215.255254
217113.78.216.0/24113.78.216.1 to 113.78.216.254113.78.216.255254
218113.78.217.0/24113.78.217.1 to 113.78.217.254113.78.217.255254
219113.78.218.0/24113.78.218.1 to 113.78.218.254113.78.218.255254
220113.78.219.0/24113.78.219.1 to 113.78.219.254113.78.219.255254
221113.78.220.0/24113.78.220.1 to 113.78.220.254113.78.220.255254
222113.78.221.0/24113.78.221.1 to 113.78.221.254113.78.221.255254
223113.78.222.0/24113.78.222.1 to 113.78.222.254113.78.222.255254
224113.78.223.0/24113.78.223.1 to 113.78.223.254113.78.223.255254
225113.78.224.0/24113.78.224.1 to 113.78.224.254113.78.224.255254
226113.78.225.0/24113.78.225.1 to 113.78.225.254113.78.225.255254
227113.78.226.0/24113.78.226.1 to 113.78.226.254113.78.226.255254
228113.78.227.0/24113.78.227.1 to 113.78.227.254113.78.227.255254
229113.78.228.0/24113.78.228.1 to 113.78.228.254113.78.228.255254
230113.78.229.0/24113.78.229.1 to 113.78.229.254113.78.229.255254
231113.78.230.0/24113.78.230.1 to 113.78.230.254113.78.230.255254
232113.78.231.0/24113.78.231.1 to 113.78.231.254113.78.231.255254
233113.78.232.0/24113.78.232.1 to 113.78.232.254113.78.232.255254
234113.78.233.0/24113.78.233.1 to 113.78.233.254113.78.233.255254
235113.78.234.0/24113.78.234.1 to 113.78.234.254113.78.234.255254
236113.78.235.0/24113.78.235.1 to 113.78.235.254113.78.235.255254
237113.78.236.0/24113.78.236.1 to 113.78.236.254113.78.236.255254
238113.78.237.0/24113.78.237.1 to 113.78.237.254113.78.237.255254
239113.78.238.0/24113.78.238.1 to 113.78.238.254113.78.238.255254
240113.78.239.0/24113.78.239.1 to 113.78.239.254113.78.239.255254
241113.78.240.0/24113.78.240.1 to 113.78.240.254113.78.240.255254
242113.78.241.0/24113.78.241.1 to 113.78.241.254113.78.241.255254
243113.78.242.0/24113.78.242.1 to 113.78.242.254113.78.242.255254
244113.78.243.0/24113.78.243.1 to 113.78.243.254113.78.243.255254
245113.78.244.0/24113.78.244.1 to 113.78.244.254113.78.244.255254
246113.78.245.0/24113.78.245.1 to 113.78.245.254113.78.245.255254
247113.78.246.0/24113.78.246.1 to 113.78.246.254113.78.246.255254
248113.78.247.0/24113.78.247.1 to 113.78.247.254113.78.247.255254
249113.78.248.0/24113.78.248.1 to 113.78.248.254113.78.248.255254
250113.78.249.0/24113.78.249.1 to 113.78.249.254113.78.249.255254
251113.78.250.0/24113.78.250.1 to 113.78.250.254113.78.250.255254
252113.78.251.0/24113.78.251.1 to 113.78.251.254113.78.251.255254
253113.78.252.0/24113.78.252.1 to 113.78.252.254113.78.252.255254
254113.78.253.0/24113.78.253.1 to 113.78.253.254113.78.253.255254
255113.78.254.0/24113.78.254.1 to 113.78.254.254113.78.254.255254
256113.78.255.0/24113.78.255.1 to 113.78.255.254113.78.255.255254

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.