Subnetting Subnet Mask Cheat Sheet

Block SizeIP AddressesUsable HostsNetmask
/3042255.255.255.252
/2986255.255.255.248
/281614255.255.255.240
/273230255.255.255.224
/266462255.255.255.192
/25128126255.255.255.128
/24256254255.255.255.0
/23512510255.255.254.0
/2210241022255.255.252.0
/2120482046255.255.248.0
/2040964094255.255.240.0
/1981928190255.255.224.0
/181638416382255.255.192.0
/173276832766255.255.128.0
/166553665534255.255.0.0