It depends on how accurate your estimates are. You owe estimated payments 4 times a year; April 15, June 15, Sept 15 and January 15 (and yes, the dates are not evenly spaced). Then you prepare a tax return that calculates your actual tax owed. If you paid more in estimates, you get a refund, and if you underpaid your estimates, you will owe the rest when you file the return.
