IPv4 calculator
Subnet details, /30·/31·/32 planning, splitting, masks, private IPs, overlap check.
What it is for
Convert between CIDR (/24) and dotted mask (255.255.255.0).
Why it helps
Handy when one system uses CIDR and another uses classic masks.
Full CIDR / mask table
| CIDR | Netmask | Wildcard | Addresses | Usable | Binary |
|---|---|---|---|---|---|
/0 |
0.0.0.0 |
255.255.255.255 |
4 294 967 296 | 4 294 967 294 | 00000000 00000000 00000000 00000000 |
/1 |
128.0.0.0 |
127.255.255.255 |
2 147 483 648 | 2 147 483 646 | 10000000 00000000 00000000 00000000 |
/2 |
192.0.0.0 |
63.255.255.255 |
1 073 741 824 | 1 073 741 822 | 11000000 00000000 00000000 00000000 |
/3 |
224.0.0.0 |
31.255.255.255 |
536 870 912 | 536 870 910 | 11100000 00000000 00000000 00000000 |
/4 |
240.0.0.0 |
15.255.255.255 |
268 435 456 | 268 435 454 | 11110000 00000000 00000000 00000000 |
/5 |
248.0.0.0 |
7.255.255.255 |
134 217 728 | 134 217 726 | 11111000 00000000 00000000 00000000 |
/6 |
252.0.0.0 |
3.255.255.255 |
67 108 864 | 67 108 862 | 11111100 00000000 00000000 00000000 |
/7 |
254.0.0.0 |
1.255.255.255 |
33 554 432 | 33 554 430 | 11111110 00000000 00000000 00000000 |
/8 |
255.0.0.0 |
0.255.255.255 |
16 777 216 | 16 777 214 | 11111111 00000000 00000000 00000000 |
/9 |
255.128.0.0 |
0.127.255.255 |
8 388 608 | 8 388 606 | 11111111 10000000 00000000 00000000 |
/10 |
255.192.0.0 |
0.63.255.255 |
4 194 304 | 4 194 302 | 11111111 11000000 00000000 00000000 |
/11 |
255.224.0.0 |
0.31.255.255 |
2 097 152 | 2 097 150 | 11111111 11100000 00000000 00000000 |
/12 |
255.240.0.0 |
0.15.255.255 |
1 048 576 | 1 048 574 | 11111111 11110000 00000000 00000000 |
/13 |
255.248.0.0 |
0.7.255.255 |
524 288 | 524 286 | 11111111 11111000 00000000 00000000 |
/14 |
255.252.0.0 |
0.3.255.255 |
262 144 | 262 142 | 11111111 11111100 00000000 00000000 |
/15 |
255.254.0.0 |
0.1.255.255 |
131 072 | 131 070 | 11111111 11111110 00000000 00000000 |
/16 |
255.255.0.0 |
0.0.255.255 |
65 536 | 65 534 | 11111111 11111111 00000000 00000000 |
/17 |
255.255.128.0 |
0.0.127.255 |
32 768 | 32 766 | 11111111 11111111 10000000 00000000 |
/18 |
255.255.192.0 |
0.0.63.255 |
16 384 | 16 382 | 11111111 11111111 11000000 00000000 |
/19 |
255.255.224.0 |
0.0.31.255 |
8 192 | 8 190 | 11111111 11111111 11100000 00000000 |
/20 |
255.255.240.0 |
0.0.15.255 |
4 096 | 4 094 | 11111111 11111111 11110000 00000000 |
/21 |
255.255.248.0 |
0.0.7.255 |
2 048 | 2 046 | 11111111 11111111 11111000 00000000 |
/22 |
255.255.252.0 |
0.0.3.255 |
1 024 | 1 022 | 11111111 11111111 11111100 00000000 |
/23 |
255.255.254.0 |
0.0.1.255 |
512 | 510 | 11111111 11111111 11111110 00000000 |
/24 |
255.255.255.0 |
0.0.0.255 |
256 | 254 | 11111111 11111111 11111111 00000000 |
/25 |
255.255.255.128 |
0.0.0.127 |
128 | 126 | 11111111 11111111 11111111 10000000 |
/26 |
255.255.255.192 |
0.0.0.63 |
64 | 62 | 11111111 11111111 11111111 11000000 |
/27 |
255.255.255.224 |
0.0.0.31 |
32 | 30 | 11111111 11111111 11111111 11100000 |
/28 |
255.255.255.240 |
0.0.0.15 |
16 | 14 | 11111111 11111111 11111111 11110000 |
/29 |
255.255.255.248 |
0.0.0.7 |
8 | 6 | 11111111 11111111 11111111 11111000 |
/30 |
255.255.255.252 |
0.0.0.3 |
4 | 2 | 11111111 11111111 11111111 11111100 |
/31 |
255.255.255.254 |
0.0.0.1 |
2 | 2 | 11111111 11111111 11111111 11111110 |
/32 |
255.255.255.255 |
0.0.0.0 |
1 | 1 | 11111111 11111111 11111111 11111111 |