How can I calculate an estimate for the amount of data I will be transferring in and out of an AWS cloud database storage? My fake company will house information for about 25,000-50,000 users and get information from hundreds of different databases via APIs.

Data Transfer: Inter-Region Data Transfer Out: Data Transfer Out Data Transfer In: VPC Peering Data Transfer: Intra-Region Data Transfer: Public IP/Elastic IP Data Transfer: 0 GB/Month v 0 GB/Month 0 GB/Month Y 0 GB/Month 0 GB/Month Y 0 GB/Month Y Data Transfer: Inter-Region Data Transfer Out: Data Transfer Out Data Transfer In: VPC Peering Data Transfer: Intra-Region Data Transfer: Public IP/Elastic IP Data Transfer: 0 GB/Month v 0 GB/Month 0 GB/Month Y 0 GB/Month 0 GB/Month Y 0 GB/Month Y