You need to transfer the calculation to the active contract by approval process. The approval process is designed for you by standard way, however you can shorten the process and skip some parts of the workflow if needed.Note that from the From the status Approved the loan is taken as a Contract and calculation numbering is changed to contract numbering.
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We are allowed to change status sequence following:
Calculation → Send Offer (changes status to Offer), Archive Contract (changes status to Archived)
Offer → Send to Approval (changes status to Waiting for Approval), Archive Contract (changes status to Archived)
Waiting for Approval → Approve Contract (changes status to Approved), Archive Contract (changes status to Archived)
Approved → Sign Contract (changes status to Signed), Archive Contract (changes status to Archived)
Signed → Activate Contract (changes status to Active), Archive Contract (changes status to Archived)
Active → Suspend Contract (changes status to Suspend), Early Termination of Contract (changes status to Closing)
Suspend → Activate Contract (changes status to Active), Early Termination of Contract (change status to Closing)
Closing → Settling of Contract (changes status to Settling), Archive Contract (changes status to Archived)
Settling → Archive Contract (changes status to Archived)
Archived → we are not allowed to changed status of archived contract
Follow up:
How to create calculation in general