read 12 volts with ads1115 15 bit resolution

Im working on a microcontroller based battery charger I have a 10k pot setup to make output 5v exactly
from 12.65 volts im trying to figure how to divide / multiply 5 volts to make it readout on a 20x4 lcd
iknow this can be dode i just dont know how CODE i have so far

#include <math.h>
#include <Wire.h>
#include <Adafruit_ADS1015.h>
#include <LiquidCrystal_I2C.h>
LiquidCrystal_I2C lcd(0x3f,20,4);
Adafruit_ADS1115 ads(0x48);
float Voltage2 = 0.0;
float Voltage = 0.0;
int outputPin= 0;
void setup(void) 
  lcd.init(); // initialize the lcd 

void loop(void) 
  float adc0;  
  adc0 = ads.readADC_SingleEnded(0);
  Voltage = (adc0 * 0.1875)/1000;

  lcd.print("Voltage: ");

yea i know its only setup to read the adc. Im just not sure what to do from here
im not looking for anyone to write this for me im just looking for suggestions on how to do the math part or maybe a formula ?