Estimate the monthly cost change implied by a Terraform plan.
A plan's cost impact is the difference between what it creates and what it destroys, which is why a large plan can still reduce spend. Expressing it as a share of current spend is what makes the change reviewable. Cost review at plan time is far cheaper than discovering the increase on the next invoice, since infrastructure created in error often runs for a full billing cycle.
Terraform Plan Cost
Delta = added resources × unit cost − destroyed resources × unit cost
Delta = added resources × unit cost − destroyed resources × unit cost A plan's cost impact is the difference between what it creates and what it destroys, which is why a large plan can still reduce spend. Expressing it as a share of current spend is what makes the change reviewable.
Cost review at plan time is far cheaper than discovering the increase on the next invoice, since infrastructure created in error often runs for a full billing cycle.
This calculator takes 5 inputs: Resources to add, Average monthly cost per added resource, Resources to destroy, Average monthly cost per destroyed resource, Current monthly spend. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.