# Java, BigDecimal. Problems with division

bigdecimaldivisionjava

I'm trying to calculate a percentage "factor". That is, given a 20%, convert it into 0.2 (my intention is to later multiply values by that and get the 20% of the values).

Anyway, the question is related with this piece of code:

``````public static void main(String[] args) {
int roundingMode = BigDecimal.ROUND_FLOOR;
BigDecimal hundred = new BigDecimal("100");
BigDecimal percentageFactor = null;
BigDecimal percentage = new BigDecimal("20");
BigDecimal value = new BigDecimal("500");
percentageFactor = percentage.divide(hundred, roundingMode);
float f = percentage.floatValue() / hundred.floatValue();
f = value.floatValue() * f;
BigDecimal aux = value.multiply(percentageFactor);
System.out.println("factor:"+percentageFactor.toString());
System.out.println("final falue:"+aux.toString());
System.out.println("Float Value:"+f);
}
``````

I would expect the outcome of this to be something like:

``````factor: 0.2
final value: 100
float value: 100
``````

but instead `percentage.divide(hundred, roundingMode);` is returning zero, an hence I get:

``````factor:0
final falue:0
Float Value:100.0
``````

What am I doing wrong? How can I divide two big decimals properly?

By the way, I'm using `BigDecimal` because I will be calculating monetary percentages, so I want control regarding rounding.

I think that the best solution is to set the requested scale when dividing: In this case perhaps 2.

``````    var hundred = new BigDecimal(100);
var percentage = new BigDecimal(20);
var value = new BigDecimal(500);

var percentageFactor =
percentage.divide(hundred,2, BigDecimal.ROUND_HALF_UP);

value = value.multiply(percentageFactor);
System.out.println("final value:"+ value);
``````

Final value: `100.00`

The multiplication is using the scale from the factors (0+2) but it can be specified too.

I'd use `ROUND_HALF_UP` for accounting (in my legislation) or `ROUND_EVEN` (for statistics) for rounding mode.