[SOLVED] Percentages

[bachx]

This is more of a mathmatical question but if anyone knows, I'd really appreciate it.

 

Say I have two numbers, for example 150 and 450....and a third number between them, say 250. I want to calculate the percentage of 250 between 150 and 450, where 150 is the 0%, and 450 is the 100%. I know there is a certain formula, but seeing math was never my favorite course, I can't just figure it out. 

[MadTechie]

$start = 150;
$end = 450;
$cValue = 250;

$currentPercent = $cValue * ($start/ $end);

 

Opps, didn't read the end of the question

 

$currentPercent = $cValue * (100 / ($end - $start))

[bachx]

Hmm, something is wrong in that formula. It sometimes gives values above 100%

 

Example:

$start = 50;

$end = 150;

$cValue = 125;

 

The result will be 125%

[vijayfreaks]

Hi...

<?php
$no1=150;
$no2=450;
$diff_no=($no2-$no1)/100;
$test_no=150;
$j=1;
for ($i=$no1;$i<=$no2;$i+=$diff_no)
{

if($i>=$test_no)
{		
	break;
}
$j++;
}
$per=$j-1;
echo "my test: ".$per."%";
?>

 

Regards,

Vijay

[AndyB]

Huge sigh:

 

$whole_thing = $high_num - $low_num; // the range, or 100%, e.g. 450-150=300
$part_thing = $some_number - $low_num; // the unknown bit of the range, e.g. 250-150=100
$percent = 100 * $part_thing / $whole_thing;// .g. 100*100/300 = 33.33%

[bachx]

Thanks vijayfreaks, that worked. But I'm not sure if looping 300 times to display the percentage is efficient. What if I had much larger numbers? Is there any more efficient approach than this?

[AndyB]

Thanks vijayfreaks, that worked. But I'm not sure if looping 300 times to display the percentage is efficient. What if I had much larger numbers? Is there any more efficient approach than this?

 

PLEASE - read my post.

[bachx]

Huge sigh:

 

$whole_thing = $high_num - $low_num; // the range, or 100%, e.g. 450-150=300
$part_thing = $some_number - $low_num; // the unknown bit of the range, e.g. 250-150=100
$percent = 100 * $part_thing / $whole_thing;// .g. 100*100/300 = 33.33%

 

Worked like a charm. Thanks!