C# Math.Round() – Examples

In this tutorial, we will learn about the C# Math.Round() method, and learn how to use this method to round a given number to the nearest integral value, with the help of examples.

Round(Decimal)

Math.Round(d) rounds a decimal value d to the nearest integral value, and rounds midpoint values to the nearest even number.

Syntax

The syntax of Round(d) method is

Math.Round(Decimal d)

where

ParameterDescription
dThe decimal number to be rounded.

Return Value

The method returns rounded Decimal value.

Example 1 – Round(d)

In this example, we will take some decimal values and round them to the nearest integral values using Math.Round() method.

C# Program

using System;
 
class Example {
    static void Main(string[] args) {
        Decimal d, result;

        d = 10.2563M;
        result = Math.Round(d);
        Console.WriteLine($"Round({d}) = {result}");

        d = 10.63M;
        result = Math.Round(d);
        Console.WriteLine($"Round({d}) = {result}");

        d = 10.5M;
        result = Math.Round(d);
        Console.WriteLine($"Round({d}) = {result}");
    }
}

Output

Round(10.2563) = 10
Round(10.63) = 11
Round(10.5) = 10

Round(Decimal, Int32)

Math.Round(d, decimals) rounds a decimal value d to a specified number of fractional digits decimals, and rounds midpoint values to the nearest even number.

Syntax

The syntax of Round(d, decimals) method is

Math.Round(Decimal d, Int32 decimals)

where

ParameterDescription
dThe decimal number to be rounded.
decimalsThe number of decimal places in the return value.

Return Value

The method returns value.

Example 2 – Round(d, decimals)

In this example, we will take some decimal values and round them to specific number of decimal points using Math.Round() method.

C# Program

using System;
 
class Example {
    static void Main(string[] args) {
        Decimal d, result;
        Int32 decimals;

        d = 10.2563M;
        decimals = 2;
        result = Math.Round(d, decimals);
        Console.WriteLine($"Round({d}, {decimals}) = {result}");

        d = 10.63524M;
        decimals = 1;
        result = Math.Round(d, decimals);
        Console.WriteLine($"Round({d}, {decimals}) = {result}");

        d = 10.5M;
        decimals = 0;
        result = Math.Round(d, decimals);
        Console.WriteLine($"Round({d}, {decimals}) = {result}");
    }
}

Output

Round(10.2563, 2) = 10.26
Round(10.63524, 1) = 10.6
Round(10.5, 0) = 10

Round(Decimal, Int32, MidpointRounding)

Math.Round(d, decimals, mode) rounds a decimal value d to a specified number of fractional digits decimals, and uses the specified rounding convention mode for midpoint values.

Syntax

The syntax of Round(d, decimals, MidpointRounding) method is

Math.Round(Decimal d, Int32 decimals, MidpointRounding mode)

where

ParameterDescription
dThe decimal number to be rounded.
decimalsThe number of decimal places in the return value.
modeSpecification for how to round d if it is midway between two other numbers.

Return Value

The method returns rounded Decimal value.

Example 3 – Round(d, decimals, mode)

In this example, we will take some decimal values and round them to specific number of decimal points with different modes using Math.Round() method.

C# Program

using System;
 
class Example {
    static void Main(string[] args) {
        Decimal d, result;
        Int32 decimals;

        d = 10.2M;
        decimals = 0;
        result = Math.Round(d, decimals, MidpointRounding.AwayFromZero);
        Console.WriteLine($"Round({d}, {decimals}, MidpointRounding.AwayFromZero)       = {result}");

        d = 10.8M;
        decimals = 0;
        result = Math.Round(d, decimals, MidpointRounding.ToEven);
        Console.WriteLine($"Round({d}, {decimals}, MidpointRounding.ToEven)             = {result}");

        d = 10.8M;
        decimals = 0;
        result = Math.Round(d, decimals, MidpointRounding.ToNegativeInfinity);
        Console.WriteLine($"Round({d}, {decimals}, MidpointRounding.ToNegativeInfinity) = {result}");

        d = 10.2M;
        decimals = 0;
        result = Math.Round(d, decimals, MidpointRounding.ToPositiveInfinity);
        Console.WriteLine($"Round({d}, {decimals}, MidpointRounding.ToPositiveInfinity) = {result}");

        d = 10.8M;
        decimals = 0;
        result = Math.Round(d, decimals, MidpointRounding.ToZero);
        Console.WriteLine($"Round({d}, {decimals}, MidpointRounding.ToZero)             = {result}");
    }
}

Output

Round(10.2, 0, MidpointRounding.AwayFromZero)       = 10
Round(10.8, 0, MidpointRounding.ToEven)             = 11
Round(10.8, 0, MidpointRounding.ToNegativeInfinity) = 10
Round(10.2, 0, MidpointRounding.ToPositiveInfinity) = 11
Round(10.8, 0, MidpointRounding.ToZero)             = 10

Round(Decimal, MidpointRounding)

Math.Round(d, mode) rounds a decimal value d to the nearest integer, and uses the specified rounding convention mode for midpoint values.

Syntax

The syntax of Round(d, mode) method is

Math.Round(Decimal d, MidpointRounding mode)

where

ParameterDescription
dThe decimal number to be rounded.
modeSpecification for how to round the value d if it is midway between two other numbers.

Return Value

The method returns rounded Decimal value.

Example 4 – Round(Decimal, MidpointRounding)

In this example, we will take some decimal values and round them with different modes using Math.Round() method.

C# Program

using System;
 
class Example {
    static void Main(string[] args) {
        Decimal d, result;

        d = 10.2M;
        result = Math.Round(d, MidpointRounding.AwayFromZero);
        Console.WriteLine($"Round({d}, MidpointRounding.AwayFromZero)       = {result}");

        d = 10.8M;
        result = Math.Round(d, MidpointRounding.ToEven);
        Console.WriteLine($"Round({d}, MidpointRounding.ToEven)             = {result}");

        d = 10.8M;
        result = Math.Round(d, MidpointRounding.ToNegativeInfinity);
        Console.WriteLine($"Round({d}, MidpointRounding.ToNegativeInfinity) = {result}");

        d = 10.2M;
        result = Math.Round(d, MidpointRounding.ToPositiveInfinity);
        Console.WriteLine($"Round({d}, MidpointRounding.ToPositiveInfinity) = {result}");

        d = 10.8M;
        result = Math.Round(d, MidpointRounding.ToZero);
        Console.WriteLine($"Round({d}, MidpointRounding.ToZero)             = {result}");
    }
}

Output

Round(10.2, MidpointRounding.AwayFromZero)       = 10
Round(10.8, MidpointRounding.ToEven)             = 11
Round(10.8, MidpointRounding.ToNegativeInfinity) = 10
Round(10.2, MidpointRounding.ToPositiveInfinity) = 11
Round(10.8, MidpointRounding.ToZero)             = 10

Round(Double)

Math.Round(d) rounds a double-precision floating-point value d to the nearest integral value, and rounds midpoint values to the nearest even number.

Syntax

The syntax of Round(d) method is

Math.Round(Double d)

where

ParameterDescription
dThe double-precision floating-point number to be rounded.

Return Value

The method returns rounded Double value.

Example 5 – Round(d)

In this example, we will take some double-precision floating-point numbers and round them to the nearest integral values using Math.Round() method.

C# Program

using System;
 
class Example {
    static void Main(string[] args) {
        Double d, result;

        d = 10.2563;
        result = Math.Round(d);
        Console.WriteLine($"Round({d}) = {result}");

        d = 10.63;
        result = Math.Round(d);
        Console.WriteLine($"Round({d}) = {result}");

        d = 10.5;
        result = Math.Round(d);
        Console.WriteLine($"Round({d}) = {result}");
    }
}

Output

Round(10.2563) = 10
Round(10.63) = 11
Round(10.5) = 10

Round(Double, Int32)

Math.Round(d, decimals) rounds a double-precision floating-point value d to a specified number of fractional digits decimals, and rounds midpoint values to the nearest even number.

Syntax

The syntax of Round(d, decimals) method is

Math.Round(Double d, Int32 decimals)

where

ParameterDescription
dThe double-precision floating-point number to be rounded.
decimalsThe number of decimal places in the return value.

Return Value

The method returns rounded Double value.

Example 6 – Round(Double, Int32)

In this example, we will take some decimal double-precision floating-point numbers and round them to specific number of decimal points using Math.Round() method.

C# Program

using System;
 
class Example {
    static void Main(string[] args) {
        Double d, result;
        Int32 decimals;

        d = 10.2563;
        decimals = 2;
        result = Math.Round(d, decimals);
        Console.WriteLine($"Round({d}, {decimals}) = {result}");

        d = 10.63524;
        decimals = 1;
        result = Math.Round(d, decimals);
        Console.WriteLine($"Round({d}, {decimals}) = {result}");

        d = 10.5;
        decimals = 0;
        result = Math.Round(d, decimals);
        Console.WriteLine($"Round({d}, {decimals}) = {result}");
    }
}

Output

Round(10.2563, 2) = 10.26
Round(10.63524, 1) = 10.6
Round(10.5, 0) = 10

Round(Double, Int32, MidpointRounding)

Math.Round(d, decimals, mode) rounds a double-precision floating-point value d to a specified number of fractional digits decimals, and uses the specified rounding convention mode for midpoint values.

Syntax

The syntax of Round(d, decimals, mode) method is

Math.Round(Double d, Int32 decimals, MidpointRounding mode)

where

ParameterDescription
dThe double-precision floating-point number to be rounded.
decimalsThe number of decimal places in the return value.
modeSpecification for how to round d if it is midway between two other numbers.

Return Value

The method returns rounded Double value.

Example 7 – Round(Double, Int32, MidpointRounding)

In this example, we will take some decimal double-precision floating-point numbers and round them to specific number of decimal points with different modes using Math.Round() method.

C# Program

using System;
 
class Example {
    static void Main(string[] args) {
        Double d, result;
        Int32 decimals;

        d = 10.2;
        decimals = 0;
        result = Math.Round(d, decimals, MidpointRounding.AwayFromZero);
        Console.WriteLine($"Round({d}, {decimals}, MidpointRounding.AwayFromZero)       = {result}");

        d = 10.8;
        decimals = 0;
        result = Math.Round(d, decimals, MidpointRounding.ToEven);
        Console.WriteLine($"Round({d}, {decimals}, MidpointRounding.ToEven)             = {result}");

        d = 10.8;
        decimals = 0;
        result = Math.Round(d, decimals, MidpointRounding.ToNegativeInfinity);
        Console.WriteLine($"Round({d}, {decimals}, MidpointRounding.ToNegativeInfinity) = {result}");

        d = 10.2;
        decimals = 0;
        result = Math.Round(d, decimals, MidpointRounding.ToPositiveInfinity);
        Console.WriteLine($"Round({d}, {decimals}, MidpointRounding.ToPositiveInfinity) = {result}");

        d = 10.8;
        decimals = 0;
        result = Math.Round(d, decimals, MidpointRounding.ToZero);
        Console.WriteLine($"Round({d}, {decimals}, MidpointRounding.ToZero)             = {result}");
    }
}

Output

Round(10.2, 0, MidpointRounding.AwayFromZero)       = 10
Round(10.8, 0, MidpointRounding.ToEven)             = 11
Round(10.8, 0, MidpointRounding.ToNegativeInfinity) = 10
Round(10.2, 0, MidpointRounding.ToPositiveInfinity) = 11
Round(10.8, 0, MidpointRounding.ToZero)             = 10

Round(Double, MidpointRounding)

Math.Round(d, mode) rounds a double-precision floating-point value d to the nearest integer, and uses the specified rounding convention mode for midpoint values.

Syntax

The syntax of Round(d, mode) method is

Math.Round(Double d, MidpointRounding mode)

where

ParameterDescription
dThe double-precision floating-point number to be rounded.
modeSpecification for how to round the value d if it is midway between two other numbers.

Return Value

The method returns rounded Double value.

Example 8 – Round(Double, MidpointRounding)

In this example, we will take some double-precision floating-point numbers and round them with different modes using Math.Round() method.

C# Program

using System;
 
class Example {
    static void Main(string[] args) {
        Double d, result;

        d = 10.2;
        result = Math.Round(d, MidpointRounding.AwayFromZero);
        Console.WriteLine($"Round({d}, MidpointRounding.AwayFromZero)       = {result}");

        d = 10.8;
        result = Math.Round(d, MidpointRounding.ToEven);
        Console.WriteLine($"Round({d}, MidpointRounding.ToEven)             = {result}");

        d = 10.8;
        result = Math.Round(d, MidpointRounding.ToNegativeInfinity);
        Console.WriteLine($"Round({d}, MidpointRounding.ToNegativeInfinity) = {result}");

        d = 10.2;
        result = Math.Round(d, MidpointRounding.ToPositiveInfinity);
        Console.WriteLine($"Round({d}, MidpointRounding.ToPositiveInfinity) = {result}");

        d = 10.8;
        result = Math.Round(d, MidpointRounding.ToZero);
        Console.WriteLine($"Round({d}, MidpointRounding.ToZero)             = {result}");
    }
}

Output

Round(10.2, MidpointRounding.AwayFromZero)       = 10
Round(10.8, MidpointRounding.ToEven)             = 11
Round(10.8, MidpointRounding.ToNegativeInfinity) = 10
Round(10.2, MidpointRounding.ToPositiveInfinity) = 11
Round(10.8, MidpointRounding.ToZero)             = 10

Conclusion

In this C# Tutorial, we have learnt the syntax of C# Math.Round() method, and also learnt how to use this method with the help of examples.