A subnet mask cheat sheet is an invaluable tool for network administrators and IT professionals, providing a quick reference to efficiently calculate and understand subnetting in IP networks. It includes essential information on subnet mask notations, CIDR notation, network and broadcast address calculation, and how to divide networks into subnets. This cheat sheet simplifies complex networking concepts, aiding in network design, troubleshooting, and optimization tasks.
Subnet masks
Main
|
Addresses |
Hosts |
Netmask |
Amount of a Class C |
| /30 |
4 |
2 |
255.255.255.252 |
1/64 |
| /29 |
8 |
6 |
255.255.255.248 |
1/32 |
| /28 |
16 |
14 |
255.255.255.240 |
1/16 |
| /27 |
32 |
30 |
255.255.255.224 |
1/8 |
| /26 |
64 |
62 |
255.255.255.192 |
1/4 |
| /25 |
128 |
126 |
255.255.255.128 |
1/2 |
| /24 |
256 |
254 |
255.255.255.0 |
1 |
| /23 |
512 |
510 |
255.255.254.0 |
2 |
| /22 |
1024 |
1022 |
255.255.252.0 |
4 |
| /21 |
2048 |
2046 |
255.255.248.0 |
8 |
| /20 |
4096 |
4094 |
255.255.240.0 |
16 |
| /19 |
8192 |
8190 |
255.255.224.0 |
32 |
| /18 |
16384 |
16382 |
255.255.192.0 |
64 |
| /17 |
32768 |
32766 |
255.255.128.0 |
128 |
| /16 |
65536 |
65534 |
255.255.0.0 |
256 |
Guide to sub-class C blocks
/25 -- 2 Subnets -- 126 Hosts/Subnet
| Network # |
IP Range |
Broadcast |
| .0 |
.1-.126 |
.127 |
| .128 |
.129-.254 |
.255 |
/30 -- 64 Subnets -- 2 Hosts/Subnet
| Network # |
IP Range |
Broadcast |
| .0 |
.1-.2 |
.3 |
| .4 |
.5-.6 |
.7 |
| .8 |
.9-.10 |
.11 |
| .12 |
.13-.14 |
.15 |
| .16 |
.17-.18 |
.19 |
| .20 |
.21-.22 |
.23 |
| .24 |
.25-.26 |
.27 |
| .28 |
.29-.30 |
.31 |
| .32 |
.33-.34 |
.35 |
| .36 |
.37-.38 |
.39 |
| .40 |
.41-.42 |
.43 |
| .44 |
.45-.46 |
.47 |
| .48 |
.49-.50 |
.51 |
| .52 |
.53-.54 |
.55 |
| .56 |
.57-.58 |
.59 |
| .60 |
.61-.62 |
.63 |
| .64 |
.65-.66 |
.67 |
| .68 |
.69-.70 |
.71 |
| .72 |
.73-.74 |
.75 |
| .76 |
.77-.78 |
.79 |
| .80 |
.81-.82 |
.83 |
| .84 |
.85-.86 |
.87 |
| .88 |
.89-.90 |
.91 |
| .92 |
.93-.94 |
.95 |
| .96 |
.97-.98 |
.99 |
| .100 |
.101-.102 |
.103 |
| .104 |
.105-.106 |
.107 |
| .108 |
.109-.110 |
.111 |
| .112 |
.113-.114 |
.115 |
| .116 |
.117-.118 |
.119 |
| .120 |
.121-.122 |
.123 |
| .124 |
.125-.126 |
.127 |
| .128 |
.129-.130 |
.131 |
| .132 |
.133-.134 |
.135 |
| .136 |
.137-.138 |
.139 |
| .140 |
.141-.142 |
.143 |
| .144 |
.145-.146 |
.147 |
| .148 |
.149-.150 |
.151 |
| .152 |
.153-.154 |
.155 |
| .156 |
.157-.158 |
.159 |
| .160 |
.161-.162 |
.163 |
| .164 |
.165-.166 |
.167 |
| .168 |
.169-.170 |
.171 |
| .172 |
.173-.174 |
.175 |
| .176 |
.177-.178 |
.179 |
| .180 |
.181-.182 |
.183 |
| .184 |
.185-.186 |
.187 |
| .188 |
.189-.190 |
.191 |
| .192 |
.193-.194 |
.195 |
| .196 |
.197-.198 |
.199 |
| .200 |
.201-.202 |
.203 |
| .204 |
.205-.206 |
.207 |
| .208 |
.209-.210 |
.211 |
| .212 |
.213-.214 |
.215 |
| .216 |
.217-.218 |
.219 |
| .220 |
.221-.222 |
.223 |
| .224 |
.225-.226 |
.227 |
| .228 |
.229-.230 |
.231 |
| .232 |
.233-.234 |
.235 |
| .236 |
.237-.238 |
.239 |
| .240 |
.241-.242 |
.243 |
| .244 |
.245-.246 |
.247 |
| .248 |
.249-.250 |
.251 |
| .252 |
.253-.254 |
.255 |
/26 -- 4 Subnets -- 62 Hosts/Subnet
| Network # |
IP Range |
Broadcast |
| .0 |
.1-.62 |
.63 |
| .64 |
.65-.126 |
.127 |
| .128 |
.129-.190 |
.191 |
| .192 |
.193-.254 |
.255 |
/27 -- 8 Subnets -- 30 Hosts/Subnet
| Network # |
IP Range |
Broadcast |
| .0 |
.1-.30 |
.31 |
| .32 |
.33-.62 |
.63 |
| .64 |
.65-.94 |
.95 |
| .96 |
.97-.126 |
.127 |
| .128 |
.129-.158 |
.159 |
| .160 |
.161-.190 |
.191 |
| .192 |
.193-.222 |
.223 |
| .224 |
.225-.254 |
.255 |
/28 -- 16 Subnets -- 14 Hosts/Subnet
| Network # |
IP Range |
Broadcast |
| .0 |
.1-.14 |
.15 |
| .16 |
.17-.30 |
.31 |
| .32 |
.33-.46 |
.47 |
| .48 |
.49-.62 |
.63 |
| .64 |
.65-.78 |
.79 |
| .80 |
.81-.94 |
.95 |
| .96 |
.97-.110 |
.111 |
| .112 |
.113-.126 |
.127 |
| .128 |
.129-.142 |
.143 |
| .144 |
.145-.158 |
.159 |
| .160 |
.161-.174 |
.175 |
| .176 |
.177-.190 |
.191 |
| .192 |
.193-.206 |
.207 |
| .208 |
.209-.222 |
.223 |
| .224 |
.225-.238 |
.239 |
| .240 |
.241-.254 |
.255 |
/29 -- 32 Subnets -- 6 Hosts/Subnet
| Network # |
IP Range |
Broadcast |
| .0 |
.1-.6 |
.7 |
| .8 |
.9-.14 |
.15 |
| .16 |
.17-.22 |
.23 |
| .24 |
.25-.30 |
.31 |
| .32 |
.33-.38 |
.39 |
| .40 |
.41-.46 |
.47 |
| .48 |
.49-.54 |
.55 |
| .56 |
.57-.62 |
.63 |
| .64 |
.65-.70 |
.71 |
| .72 |
.73-.78 |
.79 |
| .80 |
.81-.86 |
.87 |
| .88 |
.89-.94 |
.95 |
| .96 |
.97-.102 |
.103 |
| .104 |
.105-.110 |
.111 |
| .112 |
.113-.118 |
.119 |
| .120 |
.121-.126 |
.127 |
| .128 |
.129-.134 |
.135 |
| .136 |
.137-.142 |
.143 |
| .144 |
.145-.150 |
.151 |
| .152 |
.153-.158 |
.159 |
| .160 |
.161-.166 |
.167 |
| .168 |
.169-.174 |
.175 |
| .176 |
.177-.182 |
.183 |
| .184 |
.185-.190 |
.191 |
| .192 |
.193-.198 |
.199 |
| .200 |
.201-.206 |
.207 |
| .208 |
.209-.214 |
.215 |
| .216 |
.217-.222 |
.223 |
| .224 |
.225-.230 |
.231 |
| .232 |
.233-.238 |
.239 |
| .240 |
.241-.246 |
.247 |
| .248 |
.249-.254 |
.255 |
