Tax loss harvesting, am I doing it correctly?

I have AMZN stocks purchased more than a year ago at 100k$ and are now worth 150k$

I have ARKK stocks purchased more than a year ago at 20k$ and are now worth 5k$

I want to sell all my ARKK and enough AMZN in a way to have capital losses from ARKK balance out with capital gain from AMZN but not fully, I want to keep an additional 3000$ that’s not covered by the AMZN gains to use it to reduce my taxable income.

Is this the right math?

AMZN Capital Gain = 50k
ARKK Capital loss = 15k

Therefore I need to sell 15k of ARKK (all my ARKK stocks) and enough AMZN stocks that have gains totaling 12k. This way I save on paying taxes on 12k of AMZN and I reduce my taxable income by 3k. Is this correct?

Follow-up: how can I determine how many AMZN stocks I need to sell to get to a gain of 12k? (Let’s assume AMZN cost basis is 100$)

I think what I need to do here is to sell 12k/50k = 24% of my AMZN stocks. Is this correct?