I have made a simulation of voltage divider, and that give me the same value like on this calculator: http://www.ohmslawcalculator.com/voltage-divider-calculator
But when I soldered my board I have measured voltage and It was around 4.5 V, but with that calculator should be around 12 V.
My two resistors have value 2000 Ohm (2 kOhm).
I was want to make 24 V to around 12 V with voltage divider, and then 12 V pass to LM7805 so my Atmega328 will work on 5 V.
Here is my PCB how works, really I'm not sure how is it possible to voltage to be 4.5 V but should be 12 V.