VBA Data Types and Limits Decimal
Example
Dim Value As Variant
Value = CDec(1.234)
'Set Value to the smallest possible Decimal value
Value = CDec("0.0000000000000000000000000001")
The Decimal data-type is only available as a sub-type of Variant, so you must declare any variable that needs to contain a Decimal as a Variant and then assign a Decimal value using the CDec function. The keyword Decimal is a reserved word (which suggests that VBA was eventually going to add first-class support for the type), so Decimal cannot be used as a variable or procedure name.
The Decimal type requires 14 bytes of memory (in addition to the bytes required by the parent Variant) and can store numbers with up to 28 decimal places. For numbers without any decimal places, the range of allowed values is -79,228,162,514,264,337,593,543,950,335 to +79,228,162,514,264,337,593,543,950,335 inclusive. For numbers with the maximum 28 decimal places, the range of allowed values is -7.9228162514264337593543950335 to +7.9228162514264337593543950335 inclusive.
