Why use a timer?
Instead, consider using the
TextBox.TextChanged event[
^] and update your result only when there is something to do?
And do yourself a favour: stop using outdated VB constructs and start using .NET properly - instead of
CDbl
use
double.TryParse[
^] and suchlike instead - then you can let the user know when he has mistyped ... You can replace most of that code with a single call!