Calculations with percentage with jQuery

I’ve the following HTML code:

It’s a simple table with:

  • 1 input for the price without tax
  • 2 inputs for the taxes
  • 1 input for the final price with tax

All the variables looks working well but do I use the ideal way to do these type of calculations ?

function updatePriceWithTaxe() {     var total_taxes = 0;     var total_without_taxes = Number($  ('input[name="RAT_Price"]').val());      $  ('input[name="STX_Amount[]"]').each(function() {         total_taxes += Number($  (this).val());     });      // Calculs     total_taxes = total_without_taxes * total_taxes / 100;     total_with_taxes = total_without_taxes + total_taxes;      // Output     console.log(total_with_taxes.toFixed(2));     $  ('input[name="RAT_PriceTaxed"]').prop('readonly', false).val(total_with_taxes.toFixed(2)).prop('readonly', true); } 

Should I need to add some error handling around non-numbers in the tax area?

Actually, a ‘NaN’ shows up in the ‘total’ if I don’t put some number?

How can I make this?