faveo/vendor/maatwebsite/excel/docs/import/calculation.md

Calculate formulas

By default formulas inside the file are being calculated and it's result will be returned. Inside import.php config you can change the default behaviour by setting calculate to the desired preference.

If you want to enable/disable it for a single import, you can use ->calculate($boolean)

// Enable calculation
$reader->calculate();

// Disable calculation
$reader->calculate(false);