log('Returns the Internal Rate of Return for a supplied series of periodic cash flows.'); // Create new PhpSpreadsheet object $spreadsheet = new Spreadsheet(); $worksheet = $spreadsheet->getActiveSheet(); // Add some data $arguments = [ ['Initial Investment', -100.00], ['Year 1 Income', 20.00], ['Year 2 Income', 24.00, 'IRR after 3 Years'], ['Year 3 Income', 28.80], ['Year 4 Income', 34.56, 'IRR after 5 Years'], ['Year 5 Income', 41.47], ]; // Some basic formatting for the data $worksheet->fromArray($arguments, null, 'A1'); $worksheet->getStyle('B1:B6')->getNumberFormat()->setFormatCode('$#,##0.00;-$#,##0.00'); // Now the formula $worksheet->setCellValue('C4', '=IRR(B1:B4)'); $worksheet->getStyle('C4')->getNumberFormat()->setFormatCode('0.00%'); $helper->log($worksheet->getCell('C4')->getValue()); $helper->log('IRR() Result is ' . $worksheet->getCell('C4')->getFormattedValue()); $worksheet->setCellValue('C6', '=IRR(B1:B6)'); $worksheet->getStyle('C6')->getNumberFormat()->setFormatCode('0.00%'); $helper->log($worksheet->getCell('C6')->getValue()); $helper->log('IRR() Result is ' . $worksheet->getCell('C6')->getFormattedValue());