Calculate Spread value in Usd

 
I wanna calculate spread values of given currencies how can i calculate it , It would be great if there is a form or blog explaining how to calculate this.
 

If you mean to calculate spread value in the account currency per one lot :


double spread_value = 0.0;  // spread value per lot in account currency

if (OrderCalcProfit(ORDER_TYPE_BUY, _Symbol, 1.0, Ask, Bid, spread_value))
   Print (spread_value);