var current = 12000;
var june = 14600;
var may = 11200;

I want percent change with respect to 'current' month parameter. The output should be in percent and it can add or subtract w.r.t. the current month. How to do this?

var current = 12000;
var june = 14600;
var may = 11200;

I want percent change with respect to 'current' month parameter. The output should be in percent and it can add or subtract w.r.t. the current month. How to do this?

• javascript
• math
• percentage

4 Answers 4

Note that if one of your values is 0 you will get either -100% or Infinity%. This solves that problem:

   function percIncrease(a, b) {
        let percent;
        if(b !== 0) {
            if(a !== 0) {
                percent = (b - a) / a * 100;
            } else {
                percent = b * 100;
            }
        } else {
            percent = - a * 100;            
        }       
        return Math.floor(percent);
    }

Its simple maths:

var res=(current-june)/current*100.0;

var percentchange = (june - current) / current * 100.0;

If your answer is a negative number then this is a percentage increase else decrease.

It isn't an easy task to handle specials cases, increase or decrease, rounding, over 100%, etc.

function calcPc(n1,n2){
  return (((n2 - n1) / n1 * 100).toLocaleString('fullwide', {maximumFractionDigits:3}) + "%");
}
   
   
   console.log(
   
     " May: "   , calcPc(11200,12000) ,
     "\nJune:" ,  calcPc(14600,12000)
   
   )