[RESOLVED] Calculating VAT, yes I know again

[dcjones]

Hi all

Sad I know, but I am trying to calculate VAT on a price:

if I echo $row_salestotal['SUM(amount)'];
It displays: 371.89 so I know the content of the var is correct.
If I ech $vat is display 17.5, so I know that the var is correct.
If I put it all together the result displayed is 436.97.

I have read just about all the post referencing VAT calulations and I still can not see where I am going wrong.

$vat = 17.5;
$total = $row_salestotal['SUM(amount)'];
echo $vat;
echo round($totalvat = $total + ($total * 17.5 /100),2); 

Many thanks for any help you can provide.

[laserlight]

What is the problem, again?

[dcjones]

Hi Laserlight

The problem is if I have a var which I know contains "371.89" and my VAT rate is 17.5 when I run the script the result is 436.97 and it should be 55.39

$vat = 17.5;
$total = $row_salestotal['SUM(amount)'];
echo $vat;
echo round($totalvat = $total + ($total * 17.5 /100),2); 

Many thanks Laserlght

[laserlight]

It looks like your formula is wrong. Simplify the problem, state the formula clearly. This is what you are doing:

$total = 371.89;
$vat = 17.5;
$net_total = $total + $total * ($vat / 100);
echo round($net_total, 2);

[dcjones]

Hi Laserlight.

Sorry to be a pain in the neck, I have just spotted what I am doing wrong.

The Gross price is 371.89 and I need to subtract the VAT at 17.5%

Your script you kindly gave me works perfectly but it adds the VAT to the gross price.

How would I subtract it.

many thanks for all your help, I will get this into my head.

[laserlight]

Erm... it looks like it should be a simple change in the formula:

$total = 371.89;
$vat = 17.5;
$net_total = $total - $total * ($vat / 100);
echo round($net_total, 2);

You could also write it as:

$total = 371.89;
$vat = 17.5;
$net_total = $total * (1 - ($vat / 100));
echo round($net_total, 2);

[dcjones]

Hi Laserlight,

Once again I thank you, all working correctly.

Many thansk for your time.