Calculated mapping of number fields in integration with Jira

We would like to specify a conversion factor or formula to map numeric fields between Jira and Aha! numeric fields, especially a Jira number field and Aha!'s Original Estimate field. This would allow us to enter hours into a Jira number field which is mapped to Aha!'s Original Estimate field and get the correct estimate value in Aha!. The mapping would specify a formula like:

Jira number field * 60 = Aha! Original Estimate