How to Round a Number to N decimal Places in Java Example

In this example tutorial, you will learn how to round a number to n decimal places in Java.

Rounding Number with DecimalFormat

You can use the DecimalFormat class to format decimal numbers. The DecimalFormat class uses a string pattern to format the number. This pattern determines what the formatted numbers look like.

Let's round a number to two decimal places using the DecimalFormat class:

DecimalFormat decimalFormat = new DecimalFormat("#.##");
double num = 142056.1679;
String formattedNum = decimalFormat.format(num);
Double roundedNum = Double.parseDouble(formattedNum);

The above code will give the following output:


Refer to the table below to determine the output based on the pattern used:

Number Pattern Output Explanation
184883.126 ###,###.### 184,883.126 The # sign denotes a digit, the comma sign is the placeholder for a grouping separator, and the period sign is the placeholder for decimal point.
184883.126 ###.## 184883.12 The pattern has two decimal places and three digits to the right of the decimal point.
275.15 000000.000 000275.150 The use of 0 determines leading and trailing zeros.

Rounding Number with BigDecimal

To round a number to 2 decimal places with BigDecimal:

double value = 142056.1679;
BigDecimal bigDecimal = new BigDecimal(Double.toString(value));
bigDecimal = bigDecimal.setScale(2, RoundingMode.HALF_UP);

The above code will give the following output: