Java 12 introduces compact formatting where we can format long numbers for decimals, currency, or percentages into short form or long form. For example 1000 to 1K. This is very useful where we”ve limited space or requirements to show numbers in short form like K for thousand, M for million B for Billon, and so on. We can use custom strings as well to display large numbers.

Create a CompactNumberFormat Instance

To create an instance of CompactNumberFormat for a locale, you can use the related built-in method of NumberFormat.

NumberFormat formatter = NumberFormat.getCompactNumberInstance(Locale.US, NumberFormat.Style.SHORT);

Here we”re creating a formatter for US Locale and short format style, that means 1000 will be represented by 1K. Similarly we can create an instance for Long Format as shown below.

NumberFormat formatter = NumberFormat.getCompactNumberInstance(Locale.US, NumberFormat.Style.LONG);

In this case, 1000 will be represented by 1 thousand and so.

Format the Value

Once formatter is created, we can use format() method to get the required formatted number string.

//1000 will be formatted as 1K
String formatted = formatter.format(1000)

//1000000 will be formatted as 1M
formatted = formatter.format(1000000)

Example of Compact Number Formatting

In following example, we”re printing long as well as short formatted string retrived using compact number formatting.

package com.tutorialspoint;

import java.text.NumberFormat;
import java.util.Locale;

public class Tester {
   public static void main(String[] args) {
      // Create the formatter instance for Long format
      NumberFormat formatter = NumberFormat.getCompactNumberInstance(
         Locale.US, NumberFormat.Style.LONG);

      System.out.println("Long Formats");
      // get the formatted strings
      System.out.println(formatter.format(1000));
      System.out.println(formatter.format(1000 * 1000));
      System.out.println(formatter.format(1000 * 1000 * 1000));

      // Create the formatter instance for Short format
      formatter = NumberFormat.getCompactNumberInstance(
         Locale.US, NumberFormat.Style.SHORT);
		 
      // get the formatted strings
      System.out.println("Short Formats");
      System.out.println(formatter.format(1000));
      System.out.println(formatter.format(1000 * 1000));
      System.out.println(formatter.format(1000 * 1000 * 1000));
   }
}

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

Long Formats
1 thousand
1 million
1 billion
Short Formats
1K
1M
1B

Compact Number Formatting and Fraction Digits

By default fraction digit is set as zero, but we can set minimum fraction digits as well using following method.

NumberFormat formatter = NumberFormat.getCompactNumberInstance(Locale.US, NumberFormat.Style.SHORT);
formatter.setMinimumFractionDigits(3);

// It will print 10.012K
System.out.println(formatter.format(10012));

Example: Compact Number Formatting with Fractions

In following example, we”re printing long as well as short formatted string retrived using compact number formatting.

package com.tutorialspoint;

import java.text.NumberFormat;
import java.util.Locale;

public class Tester {
   public static void main(String[] args) {
      // Create the formatter instance for Short format
      NumberFormat formatter = NumberFormat.getCompactNumberInstance(
         Locale.US, NumberFormat.Style.SHORT);
      System.out.println("Without using Fractions");
      // get the formatted strings
      System.out.println(formatter.format(10012));
      System.out.println(formatter.format(10000012));

      // set the minimum 2 fraction digits to display
      formatter.setMinimumFractionDigits(2);
      System.out.println("Using Fractions");
      // get the formatted strings
      System.out.println(formatter.format(10012));
      System.out.println(formatter.format(10000012));  
   }
}

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

Without using Fractions
10K
10M
Using Fractions
10.01K
10.00M