How to caculate Fair market value for rental property for first time?

Hello,

I purchased the house in 2014 for $500,000 ( Land value was 95,000 and remaining was Improvements).

I rented the house in 2023 (last year 1st time) if I sell that house at that time it would be around $850,000 (estimates from Zillow and Redfin)

 

How do i calculate Fair market value ? Which provides breakdown for Land and Improvements?

TT is very confusing in navigating this.

 

Regards

R