Подсчет размера структуры

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
 
#define PAYROLL struct payroll
 
#define PRINT_SEPARATOR printf("\n+----------+-------------+-----------+------------+")
 
struct payroll{
 char* payer_name;
 float energy_consumption;
 float cost_of_1kv;
 float sum_to_pay;
};
 
PAYROLL readPayrollFromKeyboard(){
 PAYROLL inRoll;
 float temp;
 char temp_name[100];
 printf("Input name: ");
 
 gets(temp_name);
 inRoll.payer_name = (char*)malloc(sizeof(char) * strlen(temp_name));
 strcpy(inRoll.payer_name,temp_name);
 
 printf("Input energy consumption: ");
 scanf("%e",&temp);
 inRoll.energy_consumption = temp;
 
 printf("Input cost of 1kV: ");
 scanf("%e",&temp);
 inRoll.cost_of_1kv = temp;
 
 inRoll.sum_to_pay = inRoll.cost_of_1kv * inRoll.energy_consumption;
 //printf("The summ to be payed is: %f",inRoll.sum_to_pay);
 getchar();
 return inRoll;
}
 
void printRoll( PAYROLL outRoll ){
 int i = 0;
 PRINT_SEPARATOR;
 printf("\n| %s", outRoll.payer_name);
 for( i = 0 ; i < 9 - strlen(outRoll.payer_name);i++) printf(" ");
 printf("|    %.3f    |   %.3f   | %.3f     |", outRoll.energy_consumption, outRoll.cost_of_1kv, outRoll.sum_to_pay);
 
}
 
void printTitle(){
 PRINT_SEPARATOR;
 printf("\n| NAME     | ENERGY CONS | COST      | SUM TO PAY |");
}
 
void main(){
 PAYROLL Rolls[100];
 PAYROLL pRoll;
 char cmd = 0;
 char* buff;
 bool doWhatHaveToBeDone = true;
 int RollLen = 0, i;
 
 
 printf("Input Data.\n");
 do{
  printf("\nPrint rolls - 'p', Input new item - 'n', Quit - 'q': ");
  cmd = getchar();
  //printf("\n {%c}", cmd);
  getchar();
  switch (cmd)
  {
  case 'p':
   printTitle();
   for( i = 0 ; i < RollLen ; i++ ){
    printRoll(Rolls[i]);
   }
   PRINT_SEPARATOR;
   break;
  case 'n':
   Rolls[RollLen] = readPayrollFromKeyboard();
   RollLen++;
   break;
  case 'q':
   doWhatHaveToBeDone = false;
   break;
  default:
   printf("Unknown command.");
   break;
  }
 }while(doWhatHaveToBeDone);
 
 printf("Press any button to exit.");
 getchar();
 getchar();
 system("pause");
}