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Math.Round Method (Decimal)

Updated: February 2009

Rounds a decimal value to the nearest integral value.

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

public static decimal Round(
	decimal d
)

Parameters

d
Type: System.Decimal

A decimal number to be rounded.

Return Value

Type: System.Decimal
The integer nearest parameter d. If the fractional component of d is halfway between two integers, one of which is even and the other odd, the even number is returned. Note that this method returns a Decimal instead of an integral type.

ExceptionCondition
OverflowException

The result is outside the range of a Decimal.

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. It minimizes rounding errors that result from consistently rounding a midpoint value in a single direction.

To control the type of rounding used by the Round(Decimal) method, call the Math.Round(Decimal, MidpointRounding) overload.

The following example demonstrates rounding to nearest.

using System;

class Program
{
    static void Main()
    {
    Console.WriteLine("Classic Math.Round in CSharp");
    Console.WriteLine(Math.Round(4.4)); // 4
    Console.WriteLine(Math.Round(4.5)); // 4
    Console.WriteLine(Math.Round(4.6)); // 5
    Console.WriteLine(Math.Round(5.5)); // 6
    }
}

Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98, Windows CE, Windows Mobile for Smartphone, Windows Mobile for Pocket PC, Xbox 360, Zune

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

.NET Framework

Supported in: 3.5, 3.0, 2.0, 1.1, 1.0

.NET Compact Framework

Supported in: 3.5, 2.0, 1.0

XNA Framework

Supported in: 3.0, 2.0, 1.0

Date

History

Reason

February 2009

Expanded Return Value section.

Customer feedback.

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