diff --git a/billing-calculate.php b/billing-calculate.php
index ddf075bae0..80c4ef45ea 100755
--- a/billing-calculate.php
+++ b/billing-calculate.php
@@ -39,8 +39,11 @@ foreach (dbFetchRows('SELECT * FROM `bills` ORDER BY `bill_id`') as $bill) {
 
         $date_updated = str_replace('-', '', str_replace(':', '', str_replace(' ', '', $check['updated'])));
 
+        // Send the current dir_95th to the getRates function so it knows to aggregate or return the max in/out value and highest direction
+        $dir_95th = $bill['dir_95th'];
+
         if ($period > 0 && $dateto > $date_updated) {
-            $rate_data    = getRates($bill['bill_id'], $datefrom, $dateto);
+            $rate_data    = getRates($bill['bill_id'], $datefrom, $dateto, $dir_95th);
             $rate_95th    = $rate_data['rate_95th'];
             $dir_95th     = $rate_data['dir_95th'];
             $total_data   = $rate_data['total_data'];
diff --git a/doc/Extensions/Billing-Module.md b/doc/Extensions/Billing-Module.md
index 1e24047793..ef7b8c135c 100644
--- a/doc/Extensions/Billing-Module.md
+++ b/doc/Extensions/Billing-Module.md
@@ -23,7 +23,7 @@ Edit `/etc/cron.d/librenms` and add the following:
 
 Create billing graphs as required.
 
-## Options
+## Data Retention
 
 Billing data is stored in the MySQL database, and you may wish to purge the detailed 
 stats for old data (per-month totals will always be kept).  To enable this, add the 
@@ -36,3 +36,21 @@ $config['billing_data_purge'] = 12;     // Number of months to retain
 Data for the last complete billing cycle will always be retained - only data older than
 this by the configured number of months will be removed.  This task is performed in the
 daily cleanup tasks.
+
+## 95th Percentile Calculation
+
+For 95th Percentile billing, the default behavior is to use the highest of the input 
+or output 95th Percentile calculation.
+
+To instead use the combined total of inout + output to derive the 95th percentile,
+This can be changed on a per bill basis by setting 95th Calculation to "Aggregate".
+
+To change the default option to Aggregate,
+add the following the `config.php`:
+
+```php
+$config['billing']['95th_default_agg'] = 1;  // Set aggregate 95th as default
+```
+
+This configuration setting is cosmetic and only changes the default selected option 
+when adding a new bill
diff --git a/includes/billing.php b/includes/billing.php
index 6066326ae6..56ac500084 100644
--- a/includes/billing.php
+++ b/includes/billing.php
@@ -1,19 +1,17 @@
 <?php
 
+use LibreNMS\Config;
+
 
 function format_bytes_billing($value)
 {
-    global $config;
-
-    return format_number($value, $config['billing']['base']).'B';
+    return format_number($value, Config::get('billing.base')).'B';
 }//end format_bytes_billing()
 
 
 function format_bytes_billing_short($value)
 {
-    global $config;
-
-    return format_number($value, $config['billing']['base'], 2, 3);
+    return format_number($value, Config::get('billing.base'), 2, 3);
 }//end format_bytes_billing_short()
 
 
@@ -75,10 +73,8 @@ function getPredictedUsage($bill_day, $cur_used)
 
 function getValue($host, $port, $id, $inout)
 {
-    global $config;
-
     $oid    = 'IF-MIB::ifHC'.$inout.'Octets.'.$id;
-    $device = dbFetchRow("SELECT * from `devices` WHERE `hostname` = '".mres($host)."' LIMIT 1");
+    $device = dbFetchRow("SELECT * from `devices` WHERE `hostname` = ? LIMIT 1", array($host));
     $value  = snmp_get($device, $oid, '-Oqv');
 
     if (!is_numeric($value)) {
@@ -123,41 +119,55 @@ function getLastMeasurement($bill_id)
     return ($return);
 }//end getLastMeasurement()
 
-
-function get95thin($bill_id, $datefrom, $dateto)
+function get95thagg($bill_id, $datefrom, $dateto)
 {
-    $mq_sql           = "SELECT count(delta) FROM bill_data WHERE bill_id = '".mres($bill_id)."'";
-    $mq_sql          .= " AND timestamp > '".mres($datefrom)."' AND timestamp <= '".mres($dateto)."'";
-    $measurements     = dbFetchCell($mq_sql);
+    $mq_sql           = "SELECT count(delta) FROM bill_data WHERE bill_id = ?";
+    $mq_sql          .= " AND timestamp > ? AND timestamp <= ?";
+    $measurements     = dbFetchCell($mq_sql, array($bill_id, $datefrom, $dateto));
     $measurement_95th = (round(($measurements / 100 * 95)) - 1);
 
-    $q_95_sql  = "SELECT (in_delta / period * 8) AS rate FROM bill_data  WHERE bill_id = '".mres($bill_id)."'";
-    $q_95_sql .= " AND timestamp > '".mres($datefrom)."' AND timestamp <= '".mres($dateto)."' ORDER BY rate ASC";
-    $a_95th    = dbFetchColumn($q_95_sql);
+    $q_95_sql  = "SELECT (delta / period * 8) AS rate FROM bill_data  WHERE bill_id = ?";
+    $q_95_sql .= " AND timestamp > ? AND timestamp <= ? ORDER BY rate ASC";
+    $a_95th    = dbFetchColumn($q_95_sql, array($bill_id, $datefrom, $dateto));
     $m_95th    = $a_95th[$measurement_95th];
 
     return (round($m_95th, 2));
-}//end get95thin()
+}//end get95thagg()
+
+
+function get95thIn($bill_id, $datefrom, $dateto)
+{
+    $mq_sql           = "SELECT count(delta) FROM bill_data WHERE bill_id = ?";
+    $mq_sql          .= " AND timestamp > ? AND timestamp <= ?";
+    $measurements     = dbFetchCell($mq_sql, array($bill_id, $datefrom, $dateto));
+    $measurement_95th = (round(($measurements / 100 * 95)) - 1);
+
+    $q_95_sql  = "SELECT (in_delta / period * 8) AS rate FROM bill_data  WHERE bill_id = ?";
+    $q_95_sql .= " AND timestamp > ? AND timestamp <= ? ORDER BY rate ASC";
+    $a_95th    = dbFetchColumn($q_95_sql, array($bill_id, $datefrom, $dateto));
+    $m_95th    = $a_95th[$measurement_95th];
+
+    return (round($m_95th, 2));
+}//end get95thIn()
 
 
 function get95thout($bill_id, $datefrom, $dateto)
 {
-    $mq_sql           = "SELECT count(delta) FROM bill_data WHERE bill_id = '".mres($bill_id)."'";
-    $mq_sql          .= " AND timestamp > '".mres($datefrom)."' AND timestamp <= '".mres($dateto)."'";
-    $measurements     = dbFetchCell($mq_sql);
+    $mq_sql           = "SELECT count(delta) FROM bill_data WHERE bill_id = ?";
+    $mq_sql          .= " AND timestamp > ? AND timestamp <= ?";
+    $measurements     = dbFetchCell($mq_sql, array($bill_id, $datefrom, $dateto));
     $measurement_95th = (round(($measurements / 100 * 95)) - 1);
 
-    $q_95_sql  = "SELECT (out_delta / period * 8) AS rate FROM bill_data  WHERE bill_id = '".mres($bill_id)."'";
-    $q_95_sql .= " AND timestamp > '".mres($datefrom)."' AND timestamp <= '".mres($dateto)."' ORDER BY rate ASC";
-
-    $a_95th = dbFetchColumn($q_95_sql);
-    $m_95th = $a_95th[$measurement_95th];
+    $q_95_sql  = "SELECT (out_delta / period * 8) AS rate FROM bill_data  WHERE bill_id = ?";
+    $q_95_sql .= " AND timestamp > ? AND timestamp <= ? ORDER BY rate ASC";
+    $a_95th    = dbFetchColumn($q_95_sql, array($bill_id, $datefrom, $dateto));
+    $m_95th    = $a_95th[$measurement_95th];
 
     return (round($m_95th, 2));
 }//end get95thout()
 
 
-function getRates($bill_id, $datefrom, $dateto)
+function getRates($bill_id, $datefrom, $dateto, $dir_95th)
 {
     $data = [];
 
@@ -168,14 +178,19 @@ function getRates($bill_id, $datefrom, $dateto)
     $ptot     = $sum_data['period'];
 
     $data['rate_95th_in']  = get95thIn($bill_id, $datefrom, $dateto);
-    $data['rate_95th_out'] = get95thOut($bill_id, $datefrom, $dateto);
+    $data['rate_95th_out'] = get95thout($bill_id, $datefrom, $dateto);
 
-    if ($data['rate_95th_out'] > $data['rate_95th_in']) {
-        $data['rate_95th'] = $data['rate_95th_out'];
-        $data['dir_95th']  = 'out';
+    if ($dir_95th == 'agg') {
+        $data['rate_95th'] = get95thagg($bill_id, $datefrom, $dateto);
+        $data['dir_95th'] = 'agg';
     } else {
-        $data['rate_95th'] = $data['rate_95th_in'];
-        $data['dir_95th']  = 'in';
+        if ($data['rate_95th_out'] > $data['rate_95th_in']) {
+            $data['rate_95th'] = $data['rate_95th_out'];
+            $data['dir_95th']  = 'out';
+        } else {
+            $data['rate_95th'] = $data['rate_95th_in'];
+            $data['dir_95th']  = 'in';
+        }
     }
 
     $data['total_data']     = $mtot;
@@ -192,21 +207,21 @@ function getRates($bill_id, $datefrom, $dateto)
 
 function getTotal($bill_id, $datefrom, $dateto)
 {
-    $mtot = dbFetchCell("SELECT SUM(delta) FROM bill_data WHERE bill_id = '".mres($bill_id)."' AND timestamp > '".mres($datefrom)."' AND timestamp <= '".mres($dateto)."'");
+    $mtot = dbFetchCell("SELECT SUM(delta) FROM bill_data WHERE bill_id = ? AND timestamp > ? AND timestamp <= ?", array($bill_id, $datefrom, $dateto));
     return ($mtot);
 }//end getTotal()
 
 
 function getSum($bill_id, $datefrom, $dateto)
 {
-    $sum = dbFetchRow("SELECT SUM(period) as period, SUM(delta) as total, SUM(in_delta) as inbound, SUM(out_delta) as outbound FROM bill_data WHERE bill_id = '".mres($bill_id)."' AND timestamp > '".mres($datefrom)."' AND timestamp <= '".mres($dateto)."'");
+    $sum = dbFetchRow("SELECT SUM(period) as period, SUM(delta) as total, SUM(in_delta) as inbound, SUM(out_delta) as outbound FROM bill_data WHERE bill_id = ? AND timestamp > ? AND timestamp <= ?", array($bill_id, $datefrom, $dateto));
     return ($sum);
 }//end getSum()
 
 
 function getPeriod($bill_id, $datefrom, $dateto)
 {
-    $ptot = dbFetchCell("SELECT SUM(period) FROM bill_data WHERE bill_id = '".mres($bill_id)."' AND timestamp > '".mres($datefrom)."' AND timestamp <= '".mres($dateto)."'");
+    $ptot = dbFetchCell("SELECT SUM(period) FROM bill_data WHERE bill_id = ? AND timestamp > ? AND timestamp <= ?", array($bill_id, $datefrom, $dateto));
     return ($ptot);
 }//end getPeriod()
 
diff --git a/includes/html/modal/new_bill.inc.php b/includes/html/modal/new_bill.inc.php
index 4a76ced989..190392fb41 100644
--- a/includes/html/modal/new_bill.inc.php
+++ b/includes/html/modal/new_bill.inc.php
@@ -12,6 +12,7 @@
  */
 
 use LibreNMS\Authentication\LegacyAuth;
+use LibreNMS\Config;
 
 if (LegacyAuth::user()->hasGlobalAdmin()) {
     require 'includes/html/javascript-interfacepicker.inc.php';
@@ -73,6 +74,11 @@ if (LegacyAuth::user()->hasGlobalAdmin()) {
 
 <?php
 
+    if (Config::get('billing.95th_default_agg') == 1) {
+        $bill_data['dir_95th'] = 'agg';
+    } else {
+        $bill_data['dir_95th'] = 'in';
+    }
     $bill_data['bill_type'] = 'cdr';
     $quota = array('select_gb' => ' selected');
     $cdr = array('select_mbps' => ' selected');
diff --git a/includes/html/pages/bill/actions.inc.php b/includes/html/pages/bill/actions.inc.php
index b2824560bf..e1f5a597a0 100644
--- a/includes/html/pages/bill/actions.inc.php
+++ b/includes/html/pages/bill/actions.inc.php
@@ -84,6 +84,7 @@ if ($_POST['action'] == 'update_bill') {
             'bill_quota'  => (string)$bill_quota,
             'bill_cdr'    => (string)$bill_cdr,
             'bill_type'   => $_POST['bill_type'],
+            'dir_95th'    => $_POST['dir_95th'],
             'bill_custid' => $_POST['bill_custid'],
             'bill_ref'    => $_POST['bill_ref'],
             'bill_notes'  => $_POST['bill_notes'],
diff --git a/includes/html/pages/bill/addoreditbill.inc.php b/includes/html/pages/bill/addoreditbill.inc.php
index e255555557..c1d9b91638 100644
--- a/includes/html/pages/bill/addoreditbill.inc.php
+++ b/includes/html/pages/bill/addoreditbill.inc.php
@@ -39,6 +39,25 @@
         <option <?php echo $cdr['select_gbps'] ?> value="Gbps">Gigabits per second (Gbps)</option>
       </select>
     </div>
+    <label class="col-sm-4 control-label" for="dir_95th">95th Calculation</label>
+    <div class="col-sm-8">
+      <label class="radio-inline">
+       <input type="radio" name="dir_95th" id="dir_95th_inout" value="in"
+           <?php
+           if ($bill_data['dir_95th'] == 'in' || $bill_data['dir_95th'] == 'out') {
+                echo "checked";
+           }
+           ?> /> Max In/Out
+       </label>
+      <label class="radio-inline">
+       <input type="radio" name="dir_95th" id="dir_95th_agg" value="agg"
+           <?php
+           if ($bill_data['dir_95th'] == 'agg') {
+                echo "checked";
+           }
+           ?> /> Aggregate
+       </label>
+    </div>
   </div>
   <div id="quotaDiv">
     <label class="col-sm-4 control-label" for="bill_quota">Quota</label>
diff --git a/includes/html/pages/bills.inc.php b/includes/html/pages/bills.inc.php
index 46b0d820fe..84398ad839 100644
--- a/includes/html/pages/bills.inc.php
+++ b/includes/html/pages/bills.inc.php
@@ -64,7 +64,7 @@ if ($_POST['addbill'] == 'yes') {
         'rate_95th_in'      => 0,
         'rate_95th_out'     => 0,
         'rate_95th'         => 0,
-        'dir_95th'          => 'in',
+        'dir_95th'          => $_POST['dir_95th'],
         'total_data'        => 0,
         'total_data_in'     => 0,
         'total_data_out'    => 0,