I had a short term capital loss of, say, 500, and a long term capital gain of, say, 2000. This leaves a net capital *gain* of 1500 reported on Line 16 of Schedule D. Because of this, Line 21 will always be blank. (TurboTax help says these two lines are used to compute the carryover.) However, I do not understand why I can have a capital loss carryover from 2019 when I had a capital gain.
Okay. I think I know what's going on, but if anyone can confirm it would be appreciated. The number I am questioning is shown on the Wages & Income summary (which shows amounts for "Jobs", "Refunds", "Interest", ...) There is a line item that says "Capital Loss Carryover" with a negative value. I was assuming this is an amount that applies to this year's income (since everything else on this page does) but, in actuality, I believe it is showing the carryover amount that I will be able to apply *next* year. In my opinion, this is a pretty confusing way to present this number (assuming my interpretation is correct); TurboTax could/should have some help with this value to indicate it's meaning more clearly.
If you have long term capital loss and short term capital gain, or vice versa, they don't offset each other, because they are taxed differently. Long term gain taxed as capital gain, and a short time gain taxed as ordinary income. It is why you might have a capital loss carryover even if you have a gain this year.