How can I write this equation.
Pretty much here is what I have
(float) $total = (float) $product_price * (float) $percentage;
return (float) $total;
Although now I need to add a country percentage. Therefore if the country percentage is 10% I need to add 10% onto the current total and return it.
I use the variable $country_percentage
If I understand correctly, you want to add the percentage (tax?) to the total. If the $country_percentage is the integer '10', that would equate to '0.10'
($total * (1 + ($country_percentage / 100))
Which would be ($total * 1.10)
You use math, my friend. If your percentage is a string, remove the % symbol with str_replace() and then parse that value using intval($int) or floatval($float). That'll give you a number to work with, 10 for example.
Then you divide your country percentage by 100
10/100 = 0.1
Finally, you multiply your product price by the above value +1.
So:
//if $percentage is a string with '%' in it
$percentage = (floatval( str_replace("%", $percentage) );
$percentageNum = ($percentage/100) + 1;
$total = $product_price * $percentageNum;
Related
I have a simple code in php and would like to add 3% on bitcoin value:
</PHP
$price = "0.00001000"
$price_format = str_replace(".", "", $price);
echo ($price_format + ($price_format / 100 * 3)); // 1030
?>
Return of my code:
1030
I need the return to be:
0.0001030
Does anyone know how I can perform this calculation by following the number of houses of the price?
You can use number_format when you multiply on the 3 percent to keep decimal places intact. Multiply price by 1.03 (3%) and specify 8 decimal places.
<?php
$price = 0.00001000;
$new_price = number_format($price * 1.03, 8);
echo $new_price;
Here's a link to number_format for more info:
https://www.php.net/manual/en/function.number-format.php
When I need to add a percentage to a price in order to increase it by a certain percentage I have this formula $price * (1 + $percent / 100) which is somewhat limiting.
For example if I wanted to increase the price by 200% or 300% I'd need to create a complex code to detect if its a 3 decimal number. And then extract the first number and replace the 1 like this (2 + $percent / 100).
Is there a more elegant way to increase a price by a certain percentage?
This is my way to do:
$price = $price + ($price * $percent / 100)
Works simple, calculate te percent of the price ($price * $percent / 100) and then sums that to the initial price.
This should work on every case
$price = $price + ($percentage / 100 ) * $price
But your formula is working with 200 or 300 without problem
I'm facing some troubles with .01 values at the end of calculation and i would like to ask if someone has passed trough this issue and can give me a hand to solve mine.
I have this situation:
$total = '319.00';
$discount = '99.00';
$percentage_discount = number_format((1+($discount/$total)) * 100 - 100, 2, '.', '');
echo $percentage_discount . " %<br>";
echo $discount . "<br>";
echo number_format($total * (1-($percentage_discount / 100)), 2, '.', ''); //echo total
Result:
31.03 %
99.00
220.01
The result i need is The right percentage to get the final total value with 220.00
I know that on Magento VAT calculation was a problem similar to this, the final decimals floating was an issue from the beginning and hard to solve, but maybe some experienced person has solves this.
Remove number_format() on $persentage_discount, i.e. leave it as is:
$percentage_discount = ((1 + ($discount / $total)) * 100 - 100);
Otherwhise you are making double round during calculations and final result is 220.0143 because of that. If you want to show $persentage_discount somewhere, use printf().
Update: just simplify the task and separate displays from real calculations:
<?php
$total = '319.00';
$discount = '99.00';
$percentage_discount = ($discount / $total) * 100;
$final = $total * (1-($percentage_discount / 100));
printf('%.2f<br>', $total);
printf('%.2f<br>', $discount);
printf('%.2f%%<br>', $percentage_discount);
printf('%.2f<br>', $final);
?>
output:
319.00
99.00
31.03%
220.00
intval() will do the trick. try it and let me know
echo $new=number_format($total * (1-($percentage_discount / 100)), 2, '.', '').""; //echo total
echo intval($new);
Not sure if I'm being stupid here. Probably something obvious but when you've been staring at the same issue for hours on end it starts to drive you crazy.
I'm doing a few calcuations using PHP, all fairly straight forward.
I have a table called sales, say:
total, costs
424.53, 125
853.91, 125
To get the data I need...
gross = total - cost
vat = gross - ( gross / 1.2 )
profit = gross - vat
I need to generate a report, so for each row in the sales database I need to loop over and run the above calculations to get the data I need.
If I add the sum of total and the sum of costs, and then work out the gross, vat and profit above, and round vat and profit to 2 decimal plates the values are as expected.
The problem I'm having is where I'm looping over each row and calculating gross, vat and profit. If I don't round vat and profit on each row, but round the final totals, they match the values where I add sum(total) and sum(costs).
But then in the report I generate, if I don't round vat and profit then they don't show to two decimal places, which I need.
Actual code is below, pretty sure it's more of a logic issue than code.
$sum = 0; // Test variable
foreach( .. as ... )
{
// Assigning $total and $cost
$gross = $total - $cost;
$data['profit'] = $gross;
// If I round this VAT so vat shows to two decimal points, $sum becomes off by some pence.
// If I don't round it but then round $sum after the loop, it matches the echo statement value which is the correct amount
$vat = $this->vat( $gross );
$data['vat'] = $vat;
$profit = $gross - $vat;
$data['net_profit'] = $profit;
$sum += $profit;
$array[] = $data;
}
echo "131547.82<br><br>";
echo $sum;
die;
It's an accuracy problem caused by using floats.
When you do calculations with pure PHP you need to be careful.
You may run into glitches, when comparing two floats.
I would suggest to use some helper function or a currency / money object in order to work with them. It might be better to use a PHP Extension for math stuff, like the PHP Extensions BCMath, which has for instance the function bcadd(). Anyway, here are some helpers, which you might use in your calculation loop.
/**
* turn "string float" into "rounded float with precision 2"
* (string) 123,19124124 = (float) 123.19
*
* #param type $string
*/
function formatNumber($string, $precision = 2)
{
return round((float) str_replace(',', '.', $string), $precision);
}
There is also sprintf: echo sprintf("%.2f", $a);.
These two are based on PHP's NumberFormatter from the Intl Extension.
// 123,19 EUR = 123.19
function parseNumber($string_number)
{
$fmt = numfmt_create('de_DE', \NumberFormatter::DECIMAL);
return numfmt_parse($fmt, $string_number);
}
// 123.19 = 123,19 EUR
function numberFormat($value)
{
$f = \NumberFormatter::create("de_DE", \NumberFormatter::CURRENCY);
return $f->formatCurrency($value, 'EUR');
}
For comparing two floats:
/**
* Do not check, that the numbers are exactly the same,
* but check that their difference is very small!
* A really small rounding error margin (epsilon) is expected.
* It's an equals check within defined precision.
*/
function compareFloats($a, $b)
{
return (abs(($a - $b) / $b) < 0.000001) ? true : false;
}
Im trying to make a calculation with the following values:
Product cost (without VAT) = 12,40 ($product)
The VAT percentage = 21%, what I will store in the database as 0,21 ($vat_perc)
The VAT is 2,604 ($vat)
edit: The VAT is per product
When I try to get the total then I get 15,00 ($total)
What I did is the following:
$total = $product + $vat
This will echo 15.004
Then I use the number_format:
echo(number_format($total,2,',','.'));
This will print 15.00
But then I want to multiply the product with 2
So that will give the following calculation:
$total = $product * 2 + $vat
Then again I use the format:
echo(number_format($total,2,',','.'));
Then the total = 30,01
I tried serveral things like ROUND en INT, but with no succes.
What am I doing wrong in this? In know that the VAT is the evil one here but I have no idea how to fix this.
$tax = round( ($price / 100) * 3.8, 2);
tax is rounded price divided by the 100 to make a clear percentage. Multiplied by the wanted stack
then you do the addition to or from your price table.
Well good to have you on the phone - maybe we can solve this faster by phone. Thank god for phones!
Cheers mate!
Here are some examples of how the numbers are rounded with PHP functions.
$product = 12.40;
$vat = 2.644;
$total = ( $product + $vat ) * 2;
var_dump( $total ); // float(30.088)
var_dump( number_format($total,2,',','.') ); // string(5) "30,09", rounded
var_dump( round( $total, 2 ) ); // float(30.09), rounded
var_dump( sprintf('%0.2f', $total ) ); // string(5) "30.09", rounded
var_dump( floor( $total * 100 ) / 100 ); // float(30.08), not rounded
All three founctions ( number_format, round, sprintf ) will round the result, to avoid the rounding and discard the decimal part after two decimal points you can use the last example.
Your initial total is 15.004 so when you call number_format that gets rounded down to 15.00. Now when you multiply by 2 your total is 15.008 which number_format will round up to 15.01. The issue isn't with the addition it is with the multiplication by 2. number_format rounds to the nearest place which for your case would be 30.01.
If you want the number to be rounded down all the time use floor, like so:
$total = floor(($product * 200)) / 100 + $vat;
echo(number_format($total,2,',','.'));