Right Sizing: Provisioning Instances to Match Workloads
AWS Whitepaper

Right Size Before Migrating

One reason for the waste is the mindset to overprovision that many IT professionals bring with them when they build their cloud infrastructure. Historically, IT departments have had to provision for peak demand. However, cloud environments minimize costs because capacity is provisioned based on average usage rather than peak usage.

When you learn how to right size, you can save up to 70% percent on your monthly bill. The key to right sizing is to understand precisely your organization’s usage needs and patterns and know how to take advantage of the elasticity of the AWS Cloud to respond to those needs.

By right sizing before a migration, you can significantly reduce your infrastructure costs. If you skip right sizing to save time, your migration speed might be faster, but you will end up with higher cloud infrastructure spend for a potentially long time.