diff --git a/application/helpers/locale_helper.php b/application/helpers/locale_helper.php
index 0a39aa985..b763a4e4e 100644
--- a/application/helpers/locale_helper.php
+++ b/application/helpers/locale_helper.php
@@ -17,23 +17,34 @@ function current_language()
 function currency_side()
 {
     $config = get_instance()->config;
+
     $fmt = new \NumberFormatter($config->item('number_locale'), \NumberFormatter::CURRENCY);
     $fmt->setSymbol(\NumberFormatter::CURRENCY_SYMBOL, $config->item('currency_symbol'));
+
     return !preg_match('/^¤/', $fmt->getPattern());
 }
 
 function quantity_decimals()
 {
     $config = get_instance()->config;
+
     return $config->item('quantity_decimals') ? $config->item('quantity_decimals') : 0;
 }
 
 function totals_decimals()
 {
 	$config = get_instance()->config;
+
 	return $config->item('currency_decimals') ? $config->item('currency_decimals') : 0;
 }
 
+function tax_decimals()
+{
+	$config = get_instance()->config;
+
+	return $config->item('tax_decimals') ? $config->item('tax_decimals') : 0;
+}
+
 function to_currency($number)
 {
     return to_decimals($number, 'currency_decimals', \NumberFormatter::CURRENCY);
@@ -74,11 +85,12 @@ function to_decimals($number, $decimals, $type=\NumberFormatter::DECIMAL)
     $fmt = new \NumberFormatter($config->item('number_locale'), $type);
     $fmt->setAttribute(\NumberFormatter::MIN_FRACTION_DIGITS, $config->item($decimals));
     $fmt->setAttribute(\NumberFormatter::MAX_FRACTION_DIGITS, $config->item($decimals));
-    if (empty($config->item('thousands_separator')))
+    if(empty($config->item('thousands_separator')))
     {
         $fmt->setAttribute(\NumberFormatter::GROUPING_SEPARATOR_SYMBOL, '');
     }
     $fmt->setSymbol(\NumberFormatter::CURRENCY_SYMBOL, $config->item('currency_symbol'));
+
     return $fmt->format($number);
 }
 
@@ -96,6 +108,7 @@ function parse_decimals($number)
     {
         $fmt->setAttribute(\NumberFormatter::GROUPING_SEPARATOR_SYMBOL, '');
     }
+
     return $fmt->parse($number);
 }
 
diff --git a/application/libraries/Sale_lib.php b/application/libraries/Sale_lib.php
index da4ed4d5b..74fc959cb 100644
--- a/application/libraries/Sale_lib.php
+++ b/application/libraries/Sale_lib.php
@@ -328,7 +328,7 @@ class Sale_lib
 
 	}
 
-	/*
+	/**
 	 * Returns 'subtotal', 'total', 'cash_total', 'payment_total', 'amount_due', 'cash_amount_due', 'paid_in_full'
 	 * 'subtotal', 'discounted_subtotal', 'tax_exclusive_subtotal'
 	 */
@@ -359,7 +359,7 @@ class Sale_lib
 			}
 			else
 			{
-				$subtotal =bcadd($subtotal, $extended_discounted_amount);
+				$subtotal = bcadd($subtotal, $extended_discounted_amount);
 			}
 		}
 
@@ -367,7 +367,7 @@ class Sale_lib
 		$totals['total_discount'] = $total_discount;
 		$totals['subtotal'] = $subtotal;
 
-		if ($this->CI->config->item('tax_included'))
+		if($this->CI->config->item('tax_included'))
 		{
 			$totals['total'] = $total;
 		}
@@ -1137,6 +1137,7 @@ class Sale_lib
 
 		return $discounted_extended_amount;
 	}
+
 	public function get_item_total($quantity, $price, $discount_percentage, $include_discount = FALSE)
 	{
 		$total = bcmul($quantity, $price);
diff --git a/application/models/Sale.php b/application/models/Sale.php
index 1112e6066..efd035629 100644
--- a/application/models/Sale.php
+++ b/application/models/Sale.php
@@ -30,23 +30,22 @@ class Sale extends CI_Model
 			)'
 		);
 
+		$decimals = totals_decimals();
+
 		$sale_price = 'sales_items.item_unit_price * sales_items.quantity_purchased * (1 - sales_items.discount_percent / 100)';
+		$tax = 'ROUND(IFNULL(SUM(sales_items_taxes.tax), 0), ' . $decimals . ')';
 
 		if($this->config->item('tax_included'))
 		{
-			$sale_total = 'SUM(' . $sale_price . ')';
-			$sale_subtotal = 'SUM(' . $sale_price . ' - sales_items_taxes.tax)';
+			$sale_total = 'ROUND(SUM(' . $sale_price . '),' . $decimals . ')';
+			$sale_subtotal = $sale_total . ' - ' . $tax;
 		}
 		else
 		{
-			$sale_total = 'SUM(' . $sale_price . ' + sales_items_taxes.tax)';
-			$sale_subtotal = 'SUM(' . $sale_price . ')';
+			$sale_subtotal = 'ROUND(SUM(' . $sale_price . '),' . $decimals . ')';
+			$sale_total = $sale_subtotal . ' + ' . $tax;
 		}
 
-		$sale_cost = 'SUM(sales_items.item_cost_price * sales_items.quantity_purchased)';
-
-		$decimals = totals_decimals();
-
 		// create a temporary table to contain all the sum of taxes per sale item
 		$this->db->query('CREATE TEMPORARY TABLE IF NOT EXISTS ' . $this->db->dbprefix('sales_items_taxes_temp') .
 			'(
@@ -80,9 +79,9 @@ class Sale extends CI_Model
 				MAX(customer_p.email) AS email,
 				MAX(customer_p.comments) AS comments,
 				' . "
-				IFNULL(ROUND($sale_total, $decimals), ROUND($sale_subtotal, $decimals)) AS amount_due,
+				IFNULL($sale_total, $sale_subtotal) AS amount_due,
 				MAX(payments.sale_payment_amount) AS amount_tendered,
-				(MAX(payments.sale_payment_amount) - IFNULL(ROUND($sale_total, $decimals), ROUND($sale_subtotal, $decimals))) AS change_due,
+				(MAX(payments.sale_payment_amount) - IFNULL($sale_total, $sale_subtotal)) AS change_due,
 				" . '
 				MAX(payments.payment_type) AS payment_type
 		');
@@ -144,23 +143,23 @@ class Sale extends CI_Model
 			)'
 		);
 
+		$decimals = totals_decimals();
+
 		$sale_price = 'sales_items.item_unit_price * sales_items.quantity_purchased * (1 - sales_items.discount_percent / 100)';
+		$sale_cost = 'ROUND(SUM(sales_items.item_cost_price * sales_items.quantity_purchased), ' . $decimals . ')';
+		$tax = 'ROUND(IFNULL(SUM(sales_items_taxes.tax), 0), ' . $decimals . ')';
 
 		if($this->config->item('tax_included'))
 		{
-			$sale_total = 'SUM(' . $sale_price . ')';
-			$sale_subtotal = 'SUM(' . $sale_price . ' - sales_items_taxes.tax)';
+			$sale_total = 'ROUND(SUM(' . $sale_price . '),' . $decimals . ')';
+			$sale_subtotal = $sale_total . ' - ' . $tax;
 		}
 		else
 		{
-			$sale_total = 'SUM(' . $sale_price . ' + sales_items_taxes.tax)';
-			$sale_subtotal = 'SUM(' . $sale_price . ')';
+			$sale_subtotal = 'ROUND(SUM(' . $sale_price . '),' . $decimals . ')';
+			$sale_total = $sale_subtotal . ' + ' . $tax;
 		}
 
-		$sale_cost = 'SUM(sales_items.item_cost_price * sales_items.quantity_purchased)';
-
-		$decimals = totals_decimals();
-
 		// create a temporary table to contain all the sum of taxes per sale item
 		$this->db->query('CREATE TEMPORARY TABLE IF NOT EXISTS ' . $this->db->dbprefix('sales_items_taxes_temp') .
 			' (INDEX(sale_id), INDEX(item_id))
@@ -189,14 +188,14 @@ class Sale extends CI_Model
 				MAX(CONCAT(customer_p.first_name, " ", customer_p.last_name)) AS customer_name,
 				MAX(customer.company_name) AS company_name,
 				' . "
-				IFNULL(ROUND($sale_subtotal, $decimals), ROUND($sale_total - IFNULL(SUM(sales_items_taxes.tax), 0), $decimals)) AS subtotal,
-				IFNULL(ROUND(SUM(sales_items_taxes.tax), $decimals), 0) AS tax,
-				IFNULL(ROUND($sale_total, $decimals), ROUND($sale_subtotal, $decimals)) AS total,
-				IFNULL(ROUND($sale_cost, $decimals), 0) AS cost,
-				IFNULL(ROUND($sale_total - IFNULL(SUM(sales_items_taxes.tax), 0) - $sale_cost, $decimals), ROUND($sale_subtotal - $sale_cost, $decimals)) AS profit,
-				IFNULL(ROUND($sale_total, $decimals), ROUND($sale_subtotal, $decimals)) AS amount_due,
+				IFNULL($sale_subtotal, $sale_total) AS subtotal,
+				$tax AS tax,
+				IFNULL($sale_total, $sale_subtotal) AS total,
+				$sale_cost AS cost,
+				(IFNULL($sale_subtotal, $sale_total) - $sale_cost) AS profit,
+				IFNULL($sale_total, $sale_subtotal) AS amount_due,
 				MAX(payments.sale_payment_amount) AS amount_tendered,
-				(MAX(payments.sale_payment_amount) - IFNULL(ROUND($sale_total, $decimals), ROUND($sale_subtotal, $decimals))) AS change_due,
+				(MAX(payments.sale_payment_amount) - IFNULL($sale_total, $sale_subtotal)) AS change_due,
 				" . '
 				MAX(payments.payment_type) AS payment_type
 		');
@@ -1082,23 +1081,23 @@ class Sale extends CI_Model
 			$where = 'sales.sale_id = ' . $this->db->escape($inputs['sale_id']);
 		}
 
+		$decimals = totals_decimals();
+
 		$sale_price = 'sales_items.item_unit_price * sales_items.quantity_purchased * (1 - sales_items.discount_percent / 100)';
+		$sale_cost = 'ROUND(IFNULL(SUM(sales_items.item_cost_price * sales_items.quantity_purchased), 0), ' . $decimals . ')';
+		$tax = 'ROUND(IFNULL(SUM(sales_items_taxes.tax), 0), ' . $decimals . ')';
 
 		if($this->config->item('tax_included'))
 		{
-			$sale_total = 'SUM(' . $sale_price . ')';
-			$sale_subtotal = 'SUM(' . $sale_price . ' - sales_items_taxes.tax)';
+			$sale_total = 'ROUND(SUM(' . $sale_price . '),' . $decimals . ')';
+			$sale_subtotal = $sale_total . ' - ' . $tax;
 		}
 		else
 		{
-			$sale_total = 'SUM(' . $sale_price . ' + sales_items_taxes.tax)';
-			$sale_subtotal = 'SUM(' . $sale_price . ')';
+			$sale_subtotal = 'ROUND(SUM(' . $sale_price . '),' . $decimals . ')';
+			$sale_total = $sale_subtotal . ' + ' . $tax;
 		}
 
-		$sale_cost = 'SUM(sales_items.item_cost_price * sales_items.quantity_purchased)';
-
-		$decimals = totals_decimals();
-
 		// create a temporary table to contain all the sum of taxes per sale item
 		$this->db->query('CREATE TEMPORARY TABLE IF NOT EXISTS ' . $this->db->dbprefix('sales_items_taxes_temp') .
 			' (INDEX(sale_id), INDEX(item_id))
@@ -1166,11 +1165,11 @@ class Sale extends CI_Model
 					MAX(payments.payment_type) AS payment_type,
 					MAX(payments.sale_payment_amount) AS sale_payment_amount,
 					' . "
-					IFNULL(ROUND($sale_subtotal, $decimals), ROUND($sale_total - IFNULL(SUM(sales_items_taxes.tax), 0), $decimals)) AS subtotal,
-					IFNULL(ROUND(SUM(sales_items_taxes.tax), $decimals), 0) AS tax,
-					IFNULL(ROUND($sale_total, $decimals), ROUND($sale_subtotal, $decimals)) AS total,
-					IFNULL(ROUND($sale_cost, $decimals), 0) AS cost,
-					IFNULL(ROUND($sale_total - IFNULL(SUM(sales_items_taxes.tax), 0) - $sale_cost, $decimals), ROUND($sale_subtotal - $sale_cost, $decimals)) AS profit
+					IFNULL($sale_subtotal, $sale_total) AS subtotal,
+					$tax AS tax,
+					IFNULL($sale_total, $sale_subtotal) AS total,
+					$sale_cost AS cost,
+					(IFNULL($sale_subtotal, $sale_total) - $sale_cost) AS profit
 					" . '
 				FROM ' . $this->db->dbprefix('sales_items') . ' AS sales_items
 				INNER JOIN ' . $this->db->dbprefix('sales') . ' AS sales
diff --git a/application/models/reports/Summary_report.php b/application/models/reports/Summary_report.php
index df2a18187..1933f10a4 100644
--- a/application/models/reports/Summary_report.php
+++ b/application/models/reports/Summary_report.php
@@ -4,9 +4,9 @@ require_once("Report.php");
 
 abstract class Summary_report extends Report
 {
-	/*
-	Private interface
-	*/
+	/**
+	 * Private interface
+	 */
 
 	private function _common_select(array $inputs)
 	{
@@ -21,23 +21,23 @@ abstract class Summary_report extends Report
 			$where .= 'sale_time BETWEEN ' . $this->db->escape(rawurldecode($inputs['start_date'])) . ' AND ' . $this->db->escape(rawurldecode($inputs['end_date']));
 		}
 
+		$decimals = totals_decimals();
+
 		$sale_price = 'sales_items.item_unit_price * sales_items.quantity_purchased * (1 - sales_items.discount_percent / 100)';
+		$sale_cost = 'ROUND(IFNULL(SUM(sales_items.item_cost_price * sales_items.quantity_purchased), 0), ' . $decimals . ')';
+		$tax = 'ROUND(IFNULL(SUM(sales_items_taxes.tax), 0), ' . $decimals . ')';
 
 		if($this->config->item('tax_included'))
 		{
-			$sale_total = 'SUM(' . $sale_price . ')';
-			$sale_subtotal = 'SUM(' . $sale_price . ' - sales_items_taxes.tax)';
+			$sale_total = 'ROUND(SUM(' . $sale_price . '),' . $decimals . ')';
+			$sale_subtotal = $sale_total . ' - ' . $tax;
 		}
 		else
 		{
-			$sale_total = 'SUM(' . $sale_price . ' + sales_items_taxes.tax)';
-			$sale_subtotal = 'SUM(' . $sale_price . ')';
+			$sale_subtotal = 'ROUND(SUM(' . $sale_price . '),' . $decimals . ')';
+			$sale_total = $sale_subtotal . ' + ' . $tax;
 		}
 
-		$sale_cost = 'SUM(sales_items.item_cost_price * sales_items.quantity_purchased)';
-
-		$decimals = totals_decimals();
-
 		// create a temporary table to contain all the sum of taxes per sale item
 		$this->db->query('CREATE TEMPORARY TABLE IF NOT EXISTS ' . $this->db->dbprefix('sales_items_taxes_temp') .
 			' (INDEX(sale_id), INDEX(item_id))
@@ -57,11 +57,11 @@ abstract class Summary_report extends Report
 		);
 
 		$this->db->select("
-				IFNULL(ROUND($sale_subtotal, $decimals), ROUND($sale_total - IFNULL(SUM(sales_items_taxes.tax), 0), $decimals)) AS subtotal,
-				IFNULL(ROUND(SUM(sales_items_taxes.tax), $decimals), 0) AS tax,
-				IFNULL(ROUND($sale_total, $decimals), ROUND($sale_subtotal, $decimals)) AS total,
-				IFNULL(ROUND($sale_cost, $decimals), 0) AS cost,
-				IFNULL(ROUND($sale_total - IFNULL(SUM(sales_items_taxes.tax), 0) - $sale_cost, $decimals), ROUND($sale_subtotal - $sale_cost, $decimals)) AS profit
+				IFNULL($sale_subtotal, $sale_total) AS subtotal,
+				$tax AS tax,
+				IFNULL($sale_total, $sale_subtotal) AS total,
+				$sale_cost AS cost,
+				(IFNULL($sale_subtotal, $sale_total) - $sale_cost) AS profit
 		");
 	}
 
@@ -100,11 +100,9 @@ abstract class Summary_report extends Report
 		}
 	}
 
-	/*
-
-	Protected class interface implemented by derived classes
-
-	*/
+	/**
+	 * Protected class interface implemented by derived classes
+	 */
 
 	abstract protected function _get_data_columns();
 
@@ -113,10 +111,8 @@ abstract class Summary_report extends Report
 	protected function _where(array $inputs)	{ $this->_common_where($inputs); }
 	protected function _group_order()			{}
 
-	/*
-
-	Public interface implementing the base abstract class, in general it should not be extended unless there is a valid reason
-
+	/**
+	 * Public interface implementing the base abstract class, in general it should not be extended unless there is a valid reason
 	*/
 
 	public function getDataColumns()