Reference>IXLSRange>HasFormula

Returns True if at least one cell in the range contains a formula; otherwise, False.

Syntax

property HasFormula: boolean;

This example checks if the worksheet one contains formula.

if Workbook.Sheets[1].UsedRange.HasFormula then 
begin
  //do something
end;

This example checks if the cell A1 contains formula.

if Workbook.Sheets[1].Cells[6,1].HasFormula then 
begin
  //do something
end;