CIDR Subnet Table Subnet Mask CIDR Prefix Total IP's Usable IP's Number of Class C networks 255.255.255.255 /32 1 1 1/256th 255.255.255.254 /31 2 0 1/128th 255.255.255.252 /30 4 2 1/64th 255.255.255.248 /29 8 6 1/32nd 255.255.255.240 /28 16 14 1/16th 255.255.255.224 /27 32 30 1/8th 255.255.255.192 /26 64 62 1/4th 255.255.255.128 /25 128 126 1 half 255.255.255.0 /24 256 254 1 255.255.254.0 /23 512 510 2 255.255.252.0 /22 1024 1022 4 255.255.248.0 /21 2048 2046 8 255.255.240.0 /20 4096 4094 16 255.255.224.0 /19 8192 8190 32 255.255.192.0 /18 16,384 16,382 64 255.255.128.0 /17 32,768 32,766 128 255.255.0.0 /16 65,536 65,534 256 255.254.0.0 /15 131,072 131,070 512 255.252.0.0 /14 262,144 262,142 1024 255.248.0.0 /13 524,288 524,286 2048 255.240.0.0 /12 1,048,576 1,048,574 4096 255.224.0.0 /11 2,097,152 2,097,150 8192 255.192.0.0 /10 4,194,304 4,194,302 16,384 255.128.0.0 /9 8,388,608 8,388,606 32,768 255.0.0.0 /8 16,777,216 16,777,214 65,536 254.0.0.0 /7 33,554,432 33,554,430 131,072 252.0.0.0 /6 67,108,864 67,108,862 262,144 248.0.0.0 /5 134,217,728 134,217,726 1,048,576 240.0.0.0 /4 268,435,456 268,435,454 2,097,152 224.0.0.0 /3 536,870,912 536,870,910 4,194,304 192.0.0.0 /2 1,073,741,824 1,073,741,822 8,388,608 128.0.0.0 /1 2,147,483,648 2,147,483,646 16,777,216 0.0.0.0 /0 4,294,967,296 4,294,967,294 33,554,432