PHP float numbers not adding correctly - decimal value missing

Question

I am trying to get the total of my variables containing numbers, some may be decimals. I need this to be to two decimal places and am using the number_format() function.

$total =  $order->order->net+$order->order->deductions+$order->order->vat+$order->order->postage+$order->order->postage_tax; 
            echo number_format((float)$total, 2, '.', '');?>

I have noticed the following values do not add up correctly and seems to be ignoring the decimal. The total should be 118.50 but instead I get 118.00.

100+0+17.5+1+0

I have researched this and found the below

http://floating-point-gui.de/basic/

I am a little confused by it. Can anyone explain what I need to do?

*EDIT Below is dump of the $order variable showing the numbers I am trying to add up. You can see the 17.5 is 17.5 and not 17. Is it because they are specified as being strings perhaps?

object(SimpleXMLElement)#12 (21) { ["id"]=> string(6) "922704" ["shopkeeper_orderno"]=> string(4) "1001" ["customer"]=> string(6) "797893" ["creationdate"]=> string(16) "29-05-2012 11:55" ["net"]=> string(3) "100" ["vat"]=> string(4) "17.5" ["status"]=> string(1) "1" ["isnew"]=> string(1) "0" ["deductions"]=> string(1) "0" ["postage"]=> string(1) "1" ["paymentmethod"]=> string(20) "PayPal " ["instructions"]=> object(SimpleXMLElement)#17 (0) { } [2]=> object(SimpleXMLElement)#22 (1) { ["items"]=> object(SimpleXMLElement)#30 (9) { ["id"]=> string(7) "1384486" ["headerID"]=> string(6) "922704" ["productID"]=> string(7) "4959678" ["description"]=> string(13) "Wedding dress" ["net"]=> string(3) "100" ["vat"]=> string(4) "17.5" ["qty"]=> string(1) "1" ["formID"]=> string(2) "-1" ["options"]=> object(SimpleXMLElement)#31 (1) { ["options"]=> array(2) { [0]=> object(SimpleXMLElement)#32 (6) { ["id"]=> string(6) "519981" ["orderDetailsID"]=> string(7) "1384486" ["optionid"]=> string(6) "646934" ["optionCost"]=> string(1) "0" ["optionVAT"]=> string(1) "0" ["customText"]=> string(9) "size : 12" } [1]=> object(SimpleXMLElement)#33 (6) { ["id"]=> string(6) "519982" ["orderDetailsID"]=> string(7) "1384486" ["optionid"]=> string(6) "647285" ["optionCost"]=> string(1) "0" ["optionVAT"]=> string(1) "0" ["customText"]=> string(14) "Colour : Ivory" } } } } } } ["postage_tax"]=> string(1) "0" ["dispatched"]=> string(1) "0" ["paybyotherid"]=> string(2) "-1" ["wheredidyouhearid"]=> string(2) "-1" }

118.50 is massively different from 118.00 so I dont think its a floating point fault here. It only occurs on really large/small numbers. Can you give a a var_dump of $order please? — craig1231
– craig1231, Commented Jun 28, 2012 at 11:38
If you pass the numbers in raw, it works. Echo out all the variables used in the calculation and verify that they really are what you think/say they are. — DaveRandom
– DaveRandom, Commented Jun 28, 2012 at 11:40

MilMike · Accepted Answer · 2012-06-28 11:41:30Z

6

you can use round and then number format:

  $total = 100+0+17.5+1+0.2;
//echo number_format((float)$total);  //119
  echo number_format(round((float)$total,2),2);  //118.50

answered Jun 28, 2012 at 11:41

MilMike

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Tufan Barış Yıldırım · Accepted Answer · 2012-06-28 11:58:31Z

3

Are you sure your all of theese vars are int or float type? Check the type as

var_dump($order->order->net, $order->order->deductions, $order->order->vat,$order->order->postage, $order->order->postage_tax);

if you used number_format for these vars they may be string, use floatval().

check the examples,

$a = 100+0+"17,5"+1+0;
    var_dump($a);

Result : int(118)

$b = 100+0+17.5+1+0;
    var_dump($b);

Result : float(118.5)

answered Jun 28, 2012 at 11:58

Tufan Barış Yıldırım

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1 Comment

LeeTee Over a year ago

The numbers are type string. I have had to convert to float and it now works. thanks

Er. Anurag Jain · Accepted Answer · 2012-06-28 11:56:57Z

2

Please check the value coming for varriable $order->order->vat. I think this is not coming 17.5 because if We assign the value you assign to varriable and add them it shows correct answer.

$a = 100;
$b = 0;
$c = 17.5;
$d = 1;
$e = 0;

$total = $a + $b + $c + $d + $e; echo number_format((float)$total, 2, '.', ''); //118.50 (Answer)

Or Use floatval($var) for getting float value of variable.

$total =  $order->order->net+$order->order->deductions+floatval($order->order->vat)+$order->order->postage+$order->order->postage_tax; 
 echo number_format((float)$total, 2, '.', '');?>

I hope it will be work.

thanks

answered Jun 28, 2012 at 11:56

Er. Anurag Jain

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jewelhuq · Accepted Answer · 2017-04-01 22:25:34Z

2

If you are looking for exact value without any correction or round you should use the bcadd following function to get the actual two decimal point

$total =  $order->order->net+$order->order->deductions+$order->order->vat+$order->order->postage+$order->order->postage_tax; 
$total=bcadd(0,$total,2);
echo $total;

answered Apr 1, 2017 at 22:25

jewelhuq

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Robbie · Accepted Answer · 2012-06-28 11:40:52Z

0

Generally, the function you want for rounding to 2dp is "round" and not "number_format".

Visibly, in your echo, they will both do the same, though. Round will permanently adjust the number if you want to do future processing with it.

Having said that, I can't see any error in your code, or any reason why the 0.5 should be dropped. I suggest you check that $order->order->vat is actually 17.5 and not 17. If it is 17, then chase it backwards to find where you've integered that (e.g. in a database or in a input validation function, for example)

answered Jun 28, 2012 at 11:40

Robbie

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