Math.Round Method (Decimal, Int32)

Rounds a decimal value to a specified precision.

Namespace: System
Assembly: mscorlib (in mscorlib.dll)

public static decimal Round (
	decimal d,
	int decimals
public static Decimal Round (
	Decimal d, 
	int decimals
public static function Round (
	d : decimal, 
	decimals : int
) : decimal



A decimal number to be rounded.


The number of significant decimal places (precision) in the return value.

Return Value

The number nearest d with a precision equal to decimals. If d is halfway between two numbers, one of which is even and the other odd, then the even number is returned. If the precision of d is less than decimals, then d is returned unchanged.

Exception typeCondition


decimals is less than 0 or greater than 28.


The result is outside the range of a Decimal.

The decimals parameter specifies the number of significant decimal places in the return value and ranges from 0 to 28. If decimals is zero, an integer is returned.

The behavior of this method follows IEEE Standard 754, section 4. This kind of rounding is sometimes called rounding to nearest, or banker's rounding.

The following example demonstrates rounding to nearest.

Math.Round(3.44, 1); //Returns 3.4.
Math.Round(3.45, 1); //Returns 3.4.
Math.Round(3.46, 1); //Returns 3.5.

System.Math.Round(3.44, 1); //Returns 3.4.
System.Math.Round(3.45, 1); //Returns 3.4.
System.Math.Round(3.46, 1); //Returns 3.5.

System.Math.Round(3.44, 1) //Returns 3.4.
System.Math.Round(3.45, 1) //Returns 3.4.
System.Math.Round(3.46, 1) //Returns 3.5.

Windows 98, Windows 2000 SP4, Windows CE, Windows Millennium Edition, Windows Mobile for Pocket PC, Windows Mobile for Smartphone, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see System Requirements.

.NET Framework

Supported in: 2.0, 1.1, 1.0

.NET Compact Framework

Supported in: 2.0, 1.0

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