How many usable hosts are available?

BitsMask Mask IPs Hosts DottedDecimalMask Classful
/8 8 16,777,216 16,777,214 255.0.0.0 ClassANetwork
/16 16 65,536 65,534 255.255.0.0 ClassBNetwork
/17 17 32,768 32,766 255.255.128.0
/18 18 16,384 16,382 255.255.192.0
/19 19 8,192 8,190 255.255.224.0
/20 20 4,096 4,094 255.255.240.0
/21 21 2,048 2,046 255.255.248.0
/22 22 1,024 1,022 255.255.252.0
/23 23 512 510 255.255.254.0
/24 24 256 254 255.255.255.0 ClassCNetwork
/25 25 128 126 255.255.255.128
/26 26 64 62 255.255.255.192
/27 27 32 30 255.255.255.224
/28 28 16 14 255.255.255.240
/29 29 8 6 255.255.255.248
/30 30 4 2 255.255.255.252
/31 31 0 255.255.255.254
/32 32 1 1 255.255.255.255 SingleHostAddress