Hello.
I'm an independent contractor, who lives in NJ; the company I contract for is based in CT but my work is done in NJ for the company. I am paid gross income once a month. I know I have to pay quarterly taxes to avoid penalties. How do I calculate my Federal/State/SE (FICA) taxes on each monthly paycheck I receive to then pay my quarterly tax liability? Also, my work schedule fluctuates monthly, therefore so does the monthly income.