@adi47 , since you entered the country in 2016 with F-1, and assuming that this was your first entry to the USA ( under any visa ), you would have been an exempt ( from counting days present in the USA for Substantial Presence Test) for full five calendar years i.e. till end of 2020.
The date on which your visa status was adjusted ( to H1-B) your exempt status was terminated. Thus you now count every day you are / were present in the USA. You are still a Non-Resident Alien ( filing 1040-NR and paying US taxes ONLY on US sourced / connected income. Once you pass the Substantial Presence Test ( SPT), you become a Resident for Tax Purposes, file form 1040 ( supported by TurboTax ) and be taxed on your world income, just like a citizen/Green Card holder.
SPT requires 183 days present in the US counting all the days present in the US in the current year , 1/3 the days present in the previous year and 1/6th the days present in previous to previous year.
Is there more I can do for you ?
pk
