Java rounding up to an int using Math.ceil

Question

int total = (int) Math.ceil(157/32);

Why does it still return 4? 157/32 = 4.90625, I need to round up, I\'ve looked around and this se

Answer 1

There are two methods by which you can round up your double value.

1. Math.ceil
2. Math.floor

If you want your answer 4.90625 as 4 then you should use Math.floor and if you want your answer 4.90625 as 5 then you can use Math.ceil

You can refer following code for that.

public class TestClass {

    public static void main(String[] args) {
        int floorValue = (int) Math.floor((double)157 / 32);
        int ceilValue = (int) Math.ceil((double)157 / 32);
        System.out.println("Floor: "+floorValue);
        System.out.println("Ceil: "+ceilValue);

    }

}

Answer 2

I know this is an old question but in my opinion, we have a better approach which is using BigDecimal to avoid precision loss. By the way, using this solution we have the possibility to use several rounding and scale strategies.

final var dividend = BigDecimal.valueOf(157);
final var divisor = BigDecimal.valueOf(32);
final var result = dividend.divide(divisor, RoundingMode.CEILING).intValue();

Answer 3

Check the solution below for your question:

int total = (int) Math.ceil(157/32);

Here you should multiply Numerator with 1.0, then it will give your answer.

int total = (int) Math.ceil(157*1.0/32);