Request for adding a calculation engine.
GemBox.Spreadsheet can read the last calculated values from the input file and we can retrieve this value from the cell's Value property. But it cannot calculate formula results on its own and when we provide a formula to a cell, it will automatically set its value to default. In other words, when we set a Formula property of an ExcelCell object, the GemBox.Spreadsheet will set this cell's value to 0.
See Formula property remarks: