There is no need for you to calculate anything on the Form 8962. The TurboTax software can do that for you.
See this TurboTax support FAQ for the form 8962 and form 1095-A as requested by the IRS for 2019 - https://ttlc.intuit.com/community/health-care/help/the-irs-is-requesting-form-8962/01/27409
