# Compiler Error CS0463

Evaluation of the decimal constant expression failed with error: 'error'

This error occurs when a constant decimal expression overflows at compile time.

Typically you get overflow errors at run time. In this case, you defined the constant expression in such a way that the compiler could evaluate the result and know that an overflow would happen.

## Example

The following code generates error CS0463.

// CS0463.cs
using System;
class MyClass
{
public static void Main()
{
const decimal myDec = 79000000000000000000000000000.0m + 79000000000000000000000000000.0m; // CS0463
Console.WriteLine(myDec.ToString());
}
}