IP/子网掩码计算器
在线 IP 地址和子网掩码计算器，支持 IPv4 / IPv6，网络地址、广播地址、可用主机范围、子网划分、同网段判断等。
子网计算
IP 地址类型判断
同网段判断
随机 IP 生成
子网划分 (VLSM)
CIDR 速查表
| CIDR | 子网掩码 | 可用主机 | 类别参考 |
|---|---|---|---|
| /1 | 128.0.0.0 | 2,147,483,646 | A |
| /2 | 192.0.0.0 | 1,073,741,822 | A |
| /3 | 224.0.0.0 | 536,870,910 | A |
| /4 | 240.0.0.0 | 268,435,454 | A |
| /5 | 248.0.0.0 | 134,217,726 | A |
| /6 | 252.0.0.0 | 67,108,862 | A |
| /7 | 254.0.0.0 | 33,554,430 | A |
| /8 | 255.0.0.0 | 16,777,214 | A |
| /9 | 255.128.0.0 | 8,388,606 | B |
| /10 | 255.192.0.0 | 4,194,302 | B |
| /11 | 255.224.0.0 | 2,097,150 | B |
| /12 | 255.240.0.0 | 1,048,574 | B |
| /13 | 255.248.0.0 | 524,286 | B |
| /14 | 255.252.0.0 | 262,142 | B |
| /15 | 255.254.0.0 | 131,070 | B |
| /16 | 255.255.0.0 | 65,534 | B |
| /17 | 255.255.128.0 | 32,766 | C |
| /18 | 255.255.192.0 | 16,382 | C |
| /19 | 255.255.224.0 | 8,190 | C |
| /20 | 255.255.240.0 | 4,094 | C |
| /21 | 255.255.248.0 | 2,046 | C |
| /22 | 255.255.252.0 | 1,022 | C |
| /23 | 255.255.254.0 | 510 | C |
| /24 | 255.255.255.0 | 254 | C |
| /25 | 255.255.255.128 | 126 | C+ |
| /26 | 255.255.255.192 | 62 | C+ |
| /27 | 255.255.255.224 | 30 | C+ |
| /28 | 255.255.255.240 | 14 | C+ |
| /29 | 255.255.255.248 | 6 | C+ |
| /30 | 255.255.255.252 | 2 | C+ |
| /31 | 255.255.255.254 | 0 | C+ |
| /32 | 255.255.255.255 | 0 | C+ |