ip
ipku.in

IPv4 Subnet Calculator

Enter an IP with a CIDR prefix or a subnet mask to see its network, broadcast, host range, and host count. You can also split the network into smaller subnets.

$ ipcalc
private IP (RFC 1918)10.3.5.0/24
network10.3.5.0/24
broadcast10.3.5.255
first host10.3.5.1
last host10.3.5.254
subnet mask255.255.255.0
wildcard0.0.0.255
addresses256
usable hosts254
classA
ipcalc 10.3.5.0/24
address00001010.00000011.00000101.00000000
subnet mask11111111.11111111.11111111.00000000
network00001010.00000011.00000101.00000000
broadcast00001010.00000011.00000101.11111111
green = network part, grey = host part
hex0x0a030500
decimal167970048
reverse dns0.5.3.10.in-addr.arpa
ipv4-mapped::ffff:a03:500

/24 split into /32 · 256 subnets

close ×
#networkhost rangebroadcast
110.3.5.0/3210.3.5.0 – 10.3.5.010.3.5.0
210.3.5.1/3210.3.5.1 – 10.3.5.110.3.5.1
310.3.5.2/3210.3.5.2 – 10.3.5.210.3.5.2
410.3.5.3/3210.3.5.3 – 10.3.5.310.3.5.3
510.3.5.4/3210.3.5.4 – 10.3.5.410.3.5.4
610.3.5.5/3210.3.5.5 – 10.3.5.510.3.5.5
710.3.5.6/3210.3.5.6 – 10.3.5.610.3.5.6
810.3.5.7/3210.3.5.7 – 10.3.5.710.3.5.7
910.3.5.8/3210.3.5.8 – 10.3.5.810.3.5.8
1010.3.5.9/3210.3.5.9 – 10.3.5.910.3.5.9
1110.3.5.10/3210.3.5.10 – 10.3.5.1010.3.5.10
1210.3.5.11/3210.3.5.11 – 10.3.5.1110.3.5.11
1310.3.5.12/3210.3.5.12 – 10.3.5.1210.3.5.12
1410.3.5.13/3210.3.5.13 – 10.3.5.1310.3.5.13
1510.3.5.14/3210.3.5.14 – 10.3.5.1410.3.5.14
1610.3.5.15/3210.3.5.15 – 10.3.5.1510.3.5.15
1710.3.5.16/3210.3.5.16 – 10.3.5.1610.3.5.16
1810.3.5.17/3210.3.5.17 – 10.3.5.1710.3.5.17
1910.3.5.18/3210.3.5.18 – 10.3.5.1810.3.5.18
2010.3.5.19/3210.3.5.19 – 10.3.5.1910.3.5.19
2110.3.5.20/3210.3.5.20 – 10.3.5.2010.3.5.20
2210.3.5.21/3210.3.5.21 – 10.3.5.2110.3.5.21
2310.3.5.22/3210.3.5.22 – 10.3.5.2210.3.5.22
2410.3.5.23/3210.3.5.23 – 10.3.5.2310.3.5.23
2510.3.5.24/3210.3.5.24 – 10.3.5.2410.3.5.24
2610.3.5.25/3210.3.5.25 – 10.3.5.2510.3.5.25
2710.3.5.26/3210.3.5.26 – 10.3.5.2610.3.5.26
2810.3.5.27/3210.3.5.27 – 10.3.5.2710.3.5.27
2910.3.5.28/3210.3.5.28 – 10.3.5.2810.3.5.28
3010.3.5.29/3210.3.5.29 – 10.3.5.2910.3.5.29
3110.3.5.30/3210.3.5.30 – 10.3.5.3010.3.5.30
3210.3.5.31/3210.3.5.31 – 10.3.5.3110.3.5.31
3310.3.5.32/3210.3.5.32 – 10.3.5.3210.3.5.32
3410.3.5.33/3210.3.5.33 – 10.3.5.3310.3.5.33
3510.3.5.34/3210.3.5.34 – 10.3.5.3410.3.5.34
3610.3.5.35/3210.3.5.35 – 10.3.5.3510.3.5.35
3710.3.5.36/3210.3.5.36 – 10.3.5.3610.3.5.36
3810.3.5.37/3210.3.5.37 – 10.3.5.3710.3.5.37
3910.3.5.38/3210.3.5.38 – 10.3.5.3810.3.5.38
4010.3.5.39/3210.3.5.39 – 10.3.5.3910.3.5.39
4110.3.5.40/3210.3.5.40 – 10.3.5.4010.3.5.40
4210.3.5.41/3210.3.5.41 – 10.3.5.4110.3.5.41
4310.3.5.42/3210.3.5.42 – 10.3.5.4210.3.5.42
4410.3.5.43/3210.3.5.43 – 10.3.5.4310.3.5.43
4510.3.5.44/3210.3.5.44 – 10.3.5.4410.3.5.44
4610.3.5.45/3210.3.5.45 – 10.3.5.4510.3.5.45
4710.3.5.46/3210.3.5.46 – 10.3.5.4610.3.5.46
4810.3.5.47/3210.3.5.47 – 10.3.5.4710.3.5.47
4910.3.5.48/3210.3.5.48 – 10.3.5.4810.3.5.48
5010.3.5.49/3210.3.5.49 – 10.3.5.4910.3.5.49
5110.3.5.50/3210.3.5.50 – 10.3.5.5010.3.5.50
5210.3.5.51/3210.3.5.51 – 10.3.5.5110.3.5.51
5310.3.5.52/3210.3.5.52 – 10.3.5.5210.3.5.52
5410.3.5.53/3210.3.5.53 – 10.3.5.5310.3.5.53
5510.3.5.54/3210.3.5.54 – 10.3.5.5410.3.5.54
5610.3.5.55/3210.3.5.55 – 10.3.5.5510.3.5.55
5710.3.5.56/3210.3.5.56 – 10.3.5.5610.3.5.56
5810.3.5.57/3210.3.5.57 – 10.3.5.5710.3.5.57
5910.3.5.58/3210.3.5.58 – 10.3.5.5810.3.5.58
6010.3.5.59/3210.3.5.59 – 10.3.5.5910.3.5.59
6110.3.5.60/3210.3.5.60 – 10.3.5.6010.3.5.60
6210.3.5.61/3210.3.5.61 – 10.3.5.6110.3.5.61
6310.3.5.62/3210.3.5.62 – 10.3.5.6210.3.5.62
6410.3.5.63/3210.3.5.63 – 10.3.5.6310.3.5.63
6510.3.5.64/3210.3.5.64 – 10.3.5.6410.3.5.64
6610.3.5.65/3210.3.5.65 – 10.3.5.6510.3.5.65
6710.3.5.66/3210.3.5.66 – 10.3.5.6610.3.5.66
6810.3.5.67/3210.3.5.67 – 10.3.5.6710.3.5.67
6910.3.5.68/3210.3.5.68 – 10.3.5.6810.3.5.68
7010.3.5.69/3210.3.5.69 – 10.3.5.6910.3.5.69
7110.3.5.70/3210.3.5.70 – 10.3.5.7010.3.5.70
7210.3.5.71/3210.3.5.71 – 10.3.5.7110.3.5.71
7310.3.5.72/3210.3.5.72 – 10.3.5.7210.3.5.72
7410.3.5.73/3210.3.5.73 – 10.3.5.7310.3.5.73
7510.3.5.74/3210.3.5.74 – 10.3.5.7410.3.5.74
7610.3.5.75/3210.3.5.75 – 10.3.5.7510.3.5.75
7710.3.5.76/3210.3.5.76 – 10.3.5.7610.3.5.76
7810.3.5.77/3210.3.5.77 – 10.3.5.7710.3.5.77
7910.3.5.78/3210.3.5.78 – 10.3.5.7810.3.5.78
8010.3.5.79/3210.3.5.79 – 10.3.5.7910.3.5.79
8110.3.5.80/3210.3.5.80 – 10.3.5.8010.3.5.80
8210.3.5.81/3210.3.5.81 – 10.3.5.8110.3.5.81
8310.3.5.82/3210.3.5.82 – 10.3.5.8210.3.5.82
8410.3.5.83/3210.3.5.83 – 10.3.5.8310.3.5.83
8510.3.5.84/3210.3.5.84 – 10.3.5.8410.3.5.84
8610.3.5.85/3210.3.5.85 – 10.3.5.8510.3.5.85
8710.3.5.86/3210.3.5.86 – 10.3.5.8610.3.5.86
8810.3.5.87/3210.3.5.87 – 10.3.5.8710.3.5.87
8910.3.5.88/3210.3.5.88 – 10.3.5.8810.3.5.88
9010.3.5.89/3210.3.5.89 – 10.3.5.8910.3.5.89
9110.3.5.90/3210.3.5.90 – 10.3.5.9010.3.5.90
9210.3.5.91/3210.3.5.91 – 10.3.5.9110.3.5.91
9310.3.5.92/3210.3.5.92 – 10.3.5.9210.3.5.92
9410.3.5.93/3210.3.5.93 – 10.3.5.9310.3.5.93
9510.3.5.94/3210.3.5.94 – 10.3.5.9410.3.5.94
9610.3.5.95/3210.3.5.95 – 10.3.5.9510.3.5.95
9710.3.5.96/3210.3.5.96 – 10.3.5.9610.3.5.96
9810.3.5.97/3210.3.5.97 – 10.3.5.9710.3.5.97
9910.3.5.98/3210.3.5.98 – 10.3.5.9810.3.5.98
10010.3.5.99/3210.3.5.99 – 10.3.5.9910.3.5.99
10110.3.5.100/3210.3.5.100 – 10.3.5.10010.3.5.100
10210.3.5.101/3210.3.5.101 – 10.3.5.10110.3.5.101
10310.3.5.102/3210.3.5.102 – 10.3.5.10210.3.5.102
10410.3.5.103/3210.3.5.103 – 10.3.5.10310.3.5.103
10510.3.5.104/3210.3.5.104 – 10.3.5.10410.3.5.104
10610.3.5.105/3210.3.5.105 – 10.3.5.10510.3.5.105
10710.3.5.106/3210.3.5.106 – 10.3.5.10610.3.5.106
10810.3.5.107/3210.3.5.107 – 10.3.5.10710.3.5.107
10910.3.5.108/3210.3.5.108 – 10.3.5.10810.3.5.108
11010.3.5.109/3210.3.5.109 – 10.3.5.10910.3.5.109
11110.3.5.110/3210.3.5.110 – 10.3.5.11010.3.5.110
11210.3.5.111/3210.3.5.111 – 10.3.5.11110.3.5.111
11310.3.5.112/3210.3.5.112 – 10.3.5.11210.3.5.112
11410.3.5.113/3210.3.5.113 – 10.3.5.11310.3.5.113
11510.3.5.114/3210.3.5.114 – 10.3.5.11410.3.5.114
11610.3.5.115/3210.3.5.115 – 10.3.5.11510.3.5.115
11710.3.5.116/3210.3.5.116 – 10.3.5.11610.3.5.116
11810.3.5.117/3210.3.5.117 – 10.3.5.11710.3.5.117
11910.3.5.118/3210.3.5.118 – 10.3.5.11810.3.5.118
12010.3.5.119/3210.3.5.119 – 10.3.5.11910.3.5.119
12110.3.5.120/3210.3.5.120 – 10.3.5.12010.3.5.120
12210.3.5.121/3210.3.5.121 – 10.3.5.12110.3.5.121
12310.3.5.122/3210.3.5.122 – 10.3.5.12210.3.5.122
12410.3.5.123/3210.3.5.123 – 10.3.5.12310.3.5.123
12510.3.5.124/3210.3.5.124 – 10.3.5.12410.3.5.124
12610.3.5.125/3210.3.5.125 – 10.3.5.12510.3.5.125
12710.3.5.126/3210.3.5.126 – 10.3.5.12610.3.5.126
12810.3.5.127/3210.3.5.127 – 10.3.5.12710.3.5.127
12910.3.5.128/3210.3.5.128 – 10.3.5.12810.3.5.128
13010.3.5.129/3210.3.5.129 – 10.3.5.12910.3.5.129
13110.3.5.130/3210.3.5.130 – 10.3.5.13010.3.5.130
13210.3.5.131/3210.3.5.131 – 10.3.5.13110.3.5.131
13310.3.5.132/3210.3.5.132 – 10.3.5.13210.3.5.132
13410.3.5.133/3210.3.5.133 – 10.3.5.13310.3.5.133
13510.3.5.134/3210.3.5.134 – 10.3.5.13410.3.5.134
13610.3.5.135/3210.3.5.135 – 10.3.5.13510.3.5.135
13710.3.5.136/3210.3.5.136 – 10.3.5.13610.3.5.136
13810.3.5.137/3210.3.5.137 – 10.3.5.13710.3.5.137
13910.3.5.138/3210.3.5.138 – 10.3.5.13810.3.5.138
14010.3.5.139/3210.3.5.139 – 10.3.5.13910.3.5.139
14110.3.5.140/3210.3.5.140 – 10.3.5.14010.3.5.140
14210.3.5.141/3210.3.5.141 – 10.3.5.14110.3.5.141
14310.3.5.142/3210.3.5.142 – 10.3.5.14210.3.5.142
14410.3.5.143/3210.3.5.143 – 10.3.5.14310.3.5.143
14510.3.5.144/3210.3.5.144 – 10.3.5.14410.3.5.144
14610.3.5.145/3210.3.5.145 – 10.3.5.14510.3.5.145
14710.3.5.146/3210.3.5.146 – 10.3.5.14610.3.5.146
14810.3.5.147/3210.3.5.147 – 10.3.5.14710.3.5.147
14910.3.5.148/3210.3.5.148 – 10.3.5.14810.3.5.148
15010.3.5.149/3210.3.5.149 – 10.3.5.14910.3.5.149
15110.3.5.150/3210.3.5.150 – 10.3.5.15010.3.5.150
15210.3.5.151/3210.3.5.151 – 10.3.5.15110.3.5.151
15310.3.5.152/3210.3.5.152 – 10.3.5.15210.3.5.152
15410.3.5.153/3210.3.5.153 – 10.3.5.15310.3.5.153
15510.3.5.154/3210.3.5.154 – 10.3.5.15410.3.5.154
15610.3.5.155/3210.3.5.155 – 10.3.5.15510.3.5.155
15710.3.5.156/3210.3.5.156 – 10.3.5.15610.3.5.156
15810.3.5.157/3210.3.5.157 – 10.3.5.15710.3.5.157
15910.3.5.158/3210.3.5.158 – 10.3.5.15810.3.5.158
16010.3.5.159/3210.3.5.159 – 10.3.5.15910.3.5.159
16110.3.5.160/3210.3.5.160 – 10.3.5.16010.3.5.160
16210.3.5.161/3210.3.5.161 – 10.3.5.16110.3.5.161
16310.3.5.162/3210.3.5.162 – 10.3.5.16210.3.5.162
16410.3.5.163/3210.3.5.163 – 10.3.5.16310.3.5.163
16510.3.5.164/3210.3.5.164 – 10.3.5.16410.3.5.164
16610.3.5.165/3210.3.5.165 – 10.3.5.16510.3.5.165
16710.3.5.166/3210.3.5.166 – 10.3.5.16610.3.5.166
16810.3.5.167/3210.3.5.167 – 10.3.5.16710.3.5.167
16910.3.5.168/3210.3.5.168 – 10.3.5.16810.3.5.168
17010.3.5.169/3210.3.5.169 – 10.3.5.16910.3.5.169
17110.3.5.170/3210.3.5.170 – 10.3.5.17010.3.5.170
17210.3.5.171/3210.3.5.171 – 10.3.5.17110.3.5.171
17310.3.5.172/3210.3.5.172 – 10.3.5.17210.3.5.172
17410.3.5.173/3210.3.5.173 – 10.3.5.17310.3.5.173
17510.3.5.174/3210.3.5.174 – 10.3.5.17410.3.5.174
17610.3.5.175/3210.3.5.175 – 10.3.5.17510.3.5.175
17710.3.5.176/3210.3.5.176 – 10.3.5.17610.3.5.176
17810.3.5.177/3210.3.5.177 – 10.3.5.17710.3.5.177
17910.3.5.178/3210.3.5.178 – 10.3.5.17810.3.5.178
18010.3.5.179/3210.3.5.179 – 10.3.5.17910.3.5.179
18110.3.5.180/3210.3.5.180 – 10.3.5.18010.3.5.180
18210.3.5.181/3210.3.5.181 – 10.3.5.18110.3.5.181
18310.3.5.182/3210.3.5.182 – 10.3.5.18210.3.5.182
18410.3.5.183/3210.3.5.183 – 10.3.5.18310.3.5.183
18510.3.5.184/3210.3.5.184 – 10.3.5.18410.3.5.184
18610.3.5.185/3210.3.5.185 – 10.3.5.18510.3.5.185
18710.3.5.186/3210.3.5.186 – 10.3.5.18610.3.5.186
18810.3.5.187/3210.3.5.187 – 10.3.5.18710.3.5.187
18910.3.5.188/3210.3.5.188 – 10.3.5.18810.3.5.188
19010.3.5.189/3210.3.5.189 – 10.3.5.18910.3.5.189
19110.3.5.190/3210.3.5.190 – 10.3.5.19010.3.5.190
19210.3.5.191/3210.3.5.191 – 10.3.5.19110.3.5.191
19310.3.5.192/3210.3.5.192 – 10.3.5.19210.3.5.192
19410.3.5.193/3210.3.5.193 – 10.3.5.19310.3.5.193
19510.3.5.194/3210.3.5.194 – 10.3.5.19410.3.5.194
19610.3.5.195/3210.3.5.195 – 10.3.5.19510.3.5.195
19710.3.5.196/3210.3.5.196 – 10.3.5.19610.3.5.196
19810.3.5.197/3210.3.5.197 – 10.3.5.19710.3.5.197
19910.3.5.198/3210.3.5.198 – 10.3.5.19810.3.5.198
20010.3.5.199/3210.3.5.199 – 10.3.5.19910.3.5.199
20110.3.5.200/3210.3.5.200 – 10.3.5.20010.3.5.200
20210.3.5.201/3210.3.5.201 – 10.3.5.20110.3.5.201
20310.3.5.202/3210.3.5.202 – 10.3.5.20210.3.5.202
20410.3.5.203/3210.3.5.203 – 10.3.5.20310.3.5.203
20510.3.5.204/3210.3.5.204 – 10.3.5.20410.3.5.204
20610.3.5.205/3210.3.5.205 – 10.3.5.20510.3.5.205
20710.3.5.206/3210.3.5.206 – 10.3.5.20610.3.5.206
20810.3.5.207/3210.3.5.207 – 10.3.5.20710.3.5.207
20910.3.5.208/3210.3.5.208 – 10.3.5.20810.3.5.208
21010.3.5.209/3210.3.5.209 – 10.3.5.20910.3.5.209
21110.3.5.210/3210.3.5.210 – 10.3.5.21010.3.5.210
21210.3.5.211/3210.3.5.211 – 10.3.5.21110.3.5.211
21310.3.5.212/3210.3.5.212 – 10.3.5.21210.3.5.212
21410.3.5.213/3210.3.5.213 – 10.3.5.21310.3.5.213
21510.3.5.214/3210.3.5.214 – 10.3.5.21410.3.5.214
21610.3.5.215/3210.3.5.215 – 10.3.5.21510.3.5.215
21710.3.5.216/3210.3.5.216 – 10.3.5.21610.3.5.216
21810.3.5.217/3210.3.5.217 – 10.3.5.21710.3.5.217
21910.3.5.218/3210.3.5.218 – 10.3.5.21810.3.5.218
22010.3.5.219/3210.3.5.219 – 10.3.5.21910.3.5.219
22110.3.5.220/3210.3.5.220 – 10.3.5.22010.3.5.220
22210.3.5.221/3210.3.5.221 – 10.3.5.22110.3.5.221
22310.3.5.222/3210.3.5.222 – 10.3.5.22210.3.5.222
22410.3.5.223/3210.3.5.223 – 10.3.5.22310.3.5.223
22510.3.5.224/3210.3.5.224 – 10.3.5.22410.3.5.224
22610.3.5.225/3210.3.5.225 – 10.3.5.22510.3.5.225
22710.3.5.226/3210.3.5.226 – 10.3.5.22610.3.5.226
22810.3.5.227/3210.3.5.227 – 10.3.5.22710.3.5.227
22910.3.5.228/3210.3.5.228 – 10.3.5.22810.3.5.228
23010.3.5.229/3210.3.5.229 – 10.3.5.22910.3.5.229
23110.3.5.230/3210.3.5.230 – 10.3.5.23010.3.5.230
23210.3.5.231/3210.3.5.231 – 10.3.5.23110.3.5.231
23310.3.5.232/3210.3.5.232 – 10.3.5.23210.3.5.232
23410.3.5.233/3210.3.5.233 – 10.3.5.23310.3.5.233
23510.3.5.234/3210.3.5.234 – 10.3.5.23410.3.5.234
23610.3.5.235/3210.3.5.235 – 10.3.5.23510.3.5.235
23710.3.5.236/3210.3.5.236 – 10.3.5.23610.3.5.236
23810.3.5.237/3210.3.5.237 – 10.3.5.23710.3.5.237
23910.3.5.238/3210.3.5.238 – 10.3.5.23810.3.5.238
24010.3.5.239/3210.3.5.239 – 10.3.5.23910.3.5.239
24110.3.5.240/3210.3.5.240 – 10.3.5.24010.3.5.240
24210.3.5.241/3210.3.5.241 – 10.3.5.24110.3.5.241
24310.3.5.242/3210.3.5.242 – 10.3.5.24210.3.5.242
24410.3.5.243/3210.3.5.243 – 10.3.5.24310.3.5.243
24510.3.5.244/3210.3.5.244 – 10.3.5.24410.3.5.244
24610.3.5.245/3210.3.5.245 – 10.3.5.24510.3.5.245
24710.3.5.246/3210.3.5.246 – 10.3.5.24610.3.5.246
24810.3.5.247/3210.3.5.247 – 10.3.5.24710.3.5.247
24910.3.5.248/3210.3.5.248 – 10.3.5.24810.3.5.248
25010.3.5.249/3210.3.5.249 – 10.3.5.24910.3.5.249
25110.3.5.250/3210.3.5.250 – 10.3.5.25010.3.5.250
25210.3.5.251/3210.3.5.251 – 10.3.5.25110.3.5.251
25310.3.5.252/3210.3.5.252 – 10.3.5.25210.3.5.252
25410.3.5.253/3210.3.5.253 – 10.3.5.25310.3.5.253
25510.3.5.254/3210.3.5.254 – 10.3.5.25410.3.5.254
25610.3.5.255/3210.3.5.255 – 10.3.5.25510.3.5.255
01 / table

IPv4 CIDR prefix table.

Click a prefix longer than your network to split it into subnets.

prefixsubnet maskaddresseshostsin your /24
/00.0.0.04,294,967,2964,294,967,294-
/1128.0.0.02,147,483,6482,147,483,646-
/2192.0.0.01,073,741,8241,073,741,822-
/3224.0.0.0536,870,912536,870,910-
/4240.0.0.0268,435,456268,435,454-
/5248.0.0.0134,217,728134,217,726-
/6252.0.0.067,108,86467,108,862-
/7254.0.0.033,554,43233,554,430-
/8255.0.0.016,777,21616,777,214-
/9255.128.0.08,388,6088,388,606-
/10255.192.0.04,194,3044,194,302-
/11255.224.0.02,097,1522,097,150-
/12255.240.0.01,048,5761,048,574-
/13255.248.0.0524,288524,286-
/14255.252.0.0262,144262,142-
/15255.254.0.0131,072131,070-
/16255.255.0.065,53665,534-
/17255.255.128.032,76832,766-
/18255.255.192.016,38416,382-
/19255.255.224.08,1928,190-
/20255.255.240.04,0964,094-
/21255.255.248.02,0482,046-
/22255.255.252.01,0241,022-
/23255.255.254.0512510-
/24255.255.255.02562541
/25255.255.255.1281281262 split →
/26255.255.255.19264624 split →
/27255.255.255.22432308 split →
/28255.255.255.240161416 split →
/29255.255.255.2488632 split →
/30255.255.255.2524264 split →
/31255.255.255.25422128 split →
/32255.255.255.25511256 split →
02 / faq

About this calculator.

How do I use this subnet calculator?

▼

Type an IP address followed by a prefix, like 192.168.1.10/24, or by a subnet mask, like 192.168.1.10 255.255.255.0. Without a prefix it uses /24. Click a row in the table to split the network into smaller subnets.

Why are usable hosts always 2 fewer?

▼

The first address in a subnet is the network address and the last is the broadcast address, so neither can go to a device. The exceptions are /31 (point-to-point links, RFC 3021) and /32 (a single address), which use every address.

Can I use it from a terminal?

▼

Yes. curl 'ipku.in/en/tools/ipv4-subnet-calculator?q=192.168.1.10/24' returns the result as plain text.

Learn how to work it out →