Java.math.BigDecimal.setScale() Method



The java.math.BigDecimal.setScale(int newScale) returns a BigDecimal whose scale is the specified value, and whose value is numerically equal to this BigDecimal's. Throws an ArithmeticException if this is not possible.

This call is typically used to increase the scale, in which case it is guaranteed that there exists a BigDecimal of the specified scale and the correct value. The call can also be used to reduce the scale if the caller knows that the BigDecimal has sufficiently many zeros at the end of its fractional part (i.e., factors of ten in its integer value) to allow for the rescaling without changing its value.

This method returns the same result as the two-argument versions of setScale, but saves the caller the trouble of specifying a rounding mode in cases where it is irrelevant.

Since BigDecimal objects are immutable, calls of this method do not result in the original object being modified, contrary to the usual convention of having methods named setX mutate field X. Instead, setScale returns an object with the proper scale; the returned object may or may not be newly allocated


Following is the declaration for java.math.BigDecimal.setScale() method.

public BigDecimal setScale(int newScale)


newScale − scale of the BigDecimal value to be returned.

Return Value

This method returns a BigDecimal whose scale is the specified value, and whose unscaled value is determined by multiplying or dividing this BigDecimal's unscaled value by the appropriate power of ten to maintain its overall value


ArithmeticException − If the specified scaling operation would require rounding.


The following example shows the usage of math.BigDecimal.setScale() method.

package com.tutorialspoint;

import java.math.*;

public class BigDecimalDemo {

   public static void main(String[] args) {

      // create 2 BigDecimal Objects
      BigDecimal bg1, bg2;

      bg1 = new BigDecimal("123.126");

      // set scale of bg1 to 6 in bg2
      bg2 = bg1.setScale(6);

      String str = "The value of " +bg1+ " after changing the scale to 6 is " +bg2;

      // print bg2 value
      System.out.println( str );

Let us compile and run the above program, this will produce the following result −

The value of 123.126 after changing the scale to 6 is 123.126000