CIDR block tool for VPC IP addresses
This tool will take an IP address written by yourself and the number of IP addresses you require for your VPC on AWS or other since this is not something you want to get wrong as you may need to migrate your resources later if you underestimate the number of IPs you need. It will then output the IP with the correct CIDR block and the IP range you will receive. Remember in AWS the first three addresses are reserved for the VPC router, DNS and future use and the final address is used as the broadcast address. Also, the amount of IP addresses that will be returned will be a close estimation of what you have requested so double check the range after entering the values. ALSO, if you’re testing this out for use with a VPC in AWS then remember that you only have between /16 (65,536 IP addresses) to /28 (16 IP addresses)!