Your IP address:
Provider:
...

For example: 3.133.152.95

/
Input
Address: 3.28.0.0
Netmask: 255.254.0.0 = 15
Inversion mask: 0.1.255.255
Binary: 00000011.00011100.00000000.00000000
Reserved: No
Result
Network: 3.28.0.0/15 (Class A)
First IP: 3.28.0.1
Last IP: 3.29.255.254
Broadcast: 3.29.255.255
Network range: 3.28.0.0 - 3.29.255.255
Number of hosts: 131070
Number of IP addresses: 131072