how to http post calculated field data into a thank-you form?

If you are referring to posting data to your own Thank You page, please follow this guide: https://www.jotform.com/help/51-How-to-Post-Submission-Data-to-Thank-You-Page

If you are referring to displaying answers in JotForm's default Thank You page, please referring to the answer provided on this forum thread: https://www.jotform.com/answers/1828059-

Please open a new forum thread if you need anything else, we will be glad to assist you.