Well I figured out that the problem is when I add, for example, 5.00 + 7,345.00, PHP just adds 5 + 7 (disregarding everything after the comma). It looks like number_format doesn't allow you to not use a comma, though for some reason print_f doesn't work when defined as a variable. Are there any other functions to use or am I just using these ones incorrectly? [code]$estTotal = $estTotal + $amount; $estTotal = printf ('$%0.2f', $estTotal);[/code] Nevermind, I figured it out. All I needed to use was: [code]number_format ($estTotal, 2, '.', '');[/code]