Unless your Single Member LLC is signed up as an S corp then nothing has changed for you. You still file it on Schedule C in your personal 1040 tax return. The quarterly taxes are just estimated payments you send in instead of withholding like from your job paychecks. Weren't you sending them in before?
Turbo Tax will calculate the 1040ES estimated payments
https://ttlc.intuit.com/community/tax-payments/help/can-turbotax-calculate-next-year-s-federal-estim...
You must make quarterly estimated tax payments for the current tax year if both of the following apply:
- 1. You expect to owe at least $1,000 in tax for the current tax year, after subtracting your withholding and credits.
- 2. You expect your withholding and credits to be less than the smaller of:
90% of the tax to be shown on your current year’s tax return, or
100% of the tax shown on your prior year’s tax return. (Your prior year tax return must cover all 12 months).
Here are the blank Estimates and instructions…..
http://www.irs.gov/pub/irs-pdf/f1040es.pdf
