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# PHP How do I round down to two decimal places?

Questions:

I need to round down a decimal in PHP to two decimal places so that:

``````49.955
``````

becomes…

``````49.95
``````

I have tried number_format, but this just rounds the value to 49.96. I cannot use substr because the number may be smaller (such as 7.950). I’ve been unable to find an answer to this so far.

Any help much appreciated.

This can work: `floor(\$number * 100) / 100`

Questions:

Here is a nice function that does the trick without using string functions:

``````<?php
function floorp(\$val, \$precision)
{
\$mult = pow(10, \$precision);
return floor(\$val * \$mult) / \$mult;
}

print floorp(49.955, 2);
?>
``````

An other option is to subtract a fraction before rounding:

``````function floorp(\$val, \$precision)
{
\$half = 0.5 / pow(10, \$precision);
return round(\$val - \$half, \$precision);
}
``````

Questions:

Multiply your input by 100, floor() it, then divide the result by 100.

Questions:

Unfortunately, none of the previous answers (including the accepted one) works for all possible inputs.

1) `sprintf('%1.'.\$precision.'f', \$val)`

Fails with a precision of 2 : 14.239 should return 14.23 (but in this case returns 14.24).

2) `floatval(substr(\$val, 0, strpos(\$val, '.') + \$precision + 1))`

Fails with a precision of 0 : 14 should return 14 (but in this case returns 1)

3) `substr(\$val, 0, strrpos(\$val, '.', 0) + (1 + \$precision))`

Fails with a precision of 0 : -1 should return -1 (but in this case returns ‘-‘)

4) `floor(\$val * pow(10, \$precision)) / pow(10, \$precision)`

Although I used this one extensively, I recently discovered a flaw in it ; it fails for some values too. With a precision of 2 : 2.05 should return 2.05 (but in this case returns 2.04 !!)

So far the only way to pass all my tests is unfortunately to use string manipulation. My solution based on rationalboss one, is :

``````function floorDec(\$val, \$precision = 2) {
if (\$precision < 0) { \$precision = 0; }
\$numPointPosition = intval(strpos(\$val, '.'));
if (\$numPointPosition === 0) { //\$val is an integer
return \$val;
}
return floatval(substr(\$val, 0, \$numPointPosition + \$precision + 1));
}
``````

This function works with positive and negative numbers, as well as any precision needed.

You can find a working example here : http://codepad.viper-7.com/ZGprQJ.

Questions:

Try the `round()` function

Like this: `round(\$num, 2, PHP_ROUND_HALF_DOWN);`

Questions:
``````    function roundDown(\$decimal, \$precision)
{
\$fraction = substr(\$decimal - floor(\$decimal), 2, \$precision); //calculates the decimal places to \$precision length
\$newDecimal = floor(\$decimal). '.' .\$fraction; // reconstructs decimal with new # of decimal places

return floatval(\$newDecimal);
}

echo roundDown(345.8768378, 5); // OUTPUT: 345.87683
``````

This function works with positive and negative numbers.

Questions:

Use formatted output

``````sprintf("%1.2f",49.955) //49.95
``````

DEMO

Questions:

You can use:

``````\$num = 49.9555;
echo substr(\$num, 0, strpos(\$num, '.') + 3);
``````

Questions:
``````sprintf("%1.2f",49.955) //49.95
Did you try `round(\$val,2)` ?
More information about the `round()` function