How does Uber driver calculate car value depreciation for tax deduction purpose?

My understanding is as a uber driver, I could either take standard mileage rate deduction or actual expense deduction, on top of either one I can also deduct car value a portion of depreciation (for me it's 2 out of 7 days) which could be $1000 a year for a car around $47k, my question is how can I calculate the car deprecation? Should I just go to KBB and simulate them by miles increase etc. ?