I'm trying to calculate compound interest of a principle amount with monthly contributions. I can't seem to figure out why my calculation aren't working. Any suggestion would be appreciated thanks.

        //Add Data to the Arrays
        while (i <= years) {
            nums.push(i + " Years");
            let newAmount = (principle * Math.pow(1 + (convertRate / frequency), frequency * i)) + ((mContribute * Math.pow(1 + (convertRate / frequency), frequency * i)) - 1) / (convertRate / frequency);
            let contributionBalance = principle + mContribute;
            let formatNum = newAmount.toFixed(2);
            balance.push(formatNum);
            contributions.push(contributionBalance);
            i++;
        }