Unit Conversion (measurement and weight) - cm to inches, meters to feet etc

[random1]

Is there any comprehensive PHP class that converts measuring units like:

 

- meters to feet

- cm to inches

- pounds to kg

 

I'm working with international weights and dimensions.

[Alex]

You don't need a class for this, although you could very well make one yourself. There are simple formulas. Example: 1 meter is ~3.280839895 feet, so:

 

function metersToFeet($meters) {
    return $meters * 3.280839895;
}

[random1]

I'm writing a function to convert inches to kilometers.

 

1 inch = 2.54 × 10-5  kilometers

 

Current Source:

 

if($fromUnit == 'in' && $toUnit == 'km')
{
	return ($value * ?????);
}

 

For this example $value = 1 and is an inch.

 

How can I fix:

 

return ($value * ?????);

 

to convert as: 1 inch = 2.54 × 10-5  kilometers