How can I calculate my quarterly taxes from being a 1099 employee?

If you are getting a 1099NEC you are not an employee.  You are an independent contractor who has a client or maybe several clients.   When you are self-employed you pay self-employment tax for Social Security and Medicare, and ordinary income tax if you earn above the standard deduction amount for your filing status.

 

https://turbotax.intuit.com/tax-tools/calculators/self-employed/

 

https://ttlc.intuit.com/community/self-employed/help/what-is-the-self-employment-tax/00/25922

 

https://ttlc.intuit.com/turbotax-support/en-us/help-article/estimated-taxes/make-estimated-tax-payments/L5svMESaC_US_en_US?uid=mdna5aoh

 

 

https://turbotax.intuit.com/tax-tools/calculators/self-employed/