Returns an expression that has been converted to a Variant of subtype Double.
CDbl(expression)
The expression argument is any valid expression.
In general, you can document your code using the subtype conversion functions to show that the result of some operation should be expressed as a particular data type rather than the default data type. For example, use CDbl or CSng to force double-precision or single-precision arithmetic in cases where currency or integer arithmetic normally would occur.
Use the CDblto provide internationally aware conversions from any other data type to a Double subtype. For example, different decimal separators and thousands separators are properly recognized depending on the locale setting of your system.