How can I truncate a double to only two decimal places in Java?

For example I have the variable 3.545555555, which I would want to truncate to just 3.54.

If you want that for display purposes, use java.text.DecimalFormat:

 new DecimalFormat("#.##").format(dblVar);

If you need it for calculations, use java.lang.Math:

 Math.floor(value * 100) / 100;

DecimalFormat df = new DecimalFormat(fmt);
df.setRoundingMode(RoundingMode.DOWN);
s = df.format(d);

Check available RoundingMode and DecimalFormat.

None of the other answers worked for both positive and negative values ( I mean for the calculation and just to do "truncate" without Rounding). and without converting to string.

From the How to round a number to n decimal places in Java link

private static BigDecimal truncateDecimal(double x,int numberofDecimals)
{
    if ( x > 0) {
        return new BigDecimal(String.valueOf(x)).setScale(numberofDecimals, BigDecimal.ROUND_FLOOR);
    } else {
        return new BigDecimal(String.valueOf(x)).setScale(numberofDecimals, BigDecimal.ROUND_CEILING);
    }
}

This method worked fine for me .

System.out.println(truncateDecimal(0, 2));
    System.out.println(truncateDecimal(9.62, 2));
    System.out.println(truncateDecimal(9.621, 2));
    System.out.println(truncateDecimal(9.629, 2));
    System.out.println(truncateDecimal(9.625, 2));
    System.out.println(truncateDecimal(9.999, 2));
    System.out.println(truncateDecimal(-9.999, 2));
    System.out.println(truncateDecimal(-9.0, 2));

Results :

0.00
9.62
9.62
9.62
9.62
9.99
-9.99
-9.00

Note first that a double is a binary fraction and does not really have decimal places.

If you need decimal places, use a BigDecimal, which has a setScale() method for truncation, or use DecimalFormat to get a String.