diff --git a/app/models/chargeback.rb b/app/models/chargeback.rb
index d1bfacc1fd7..6894b1a413a 100644
--- a/app/models/chargeback.rb
+++ b/app/models/chargeback.rb
@@ -144,9 +144,7 @@ def calculate_costs(metric_rollup_records, rates, hours_in_interval)
         if !chargeback_fields_present && r.fixed?
           cost = 0
         else
-          r.hours_in_interval = hours_in_interval
-          metric_value = r.metric_value_by(metric_rollup_records)
-          cost = r.hourly_cost(metric_value) * hours_in_interval
+          metric_value, cost = r.metric_and_cost_by(metric_rollup_records, hours_in_interval)
         end
 
         accumulate_metrics_and_costs_per_rate(r.rate_name, r.group, metric_value, cost)
diff --git a/app/models/chargeback_rate_detail.rb b/app/models/chargeback_rate_detail.rb
index ac99375788e..0a817cd7140 100644
--- a/app/models/chargeback_rate_detail.rb
+++ b/app/models/chargeback_rate_detail.rb
@@ -210,6 +210,12 @@ def contiguous_tiers?
     !error
   end
 
+  def metric_and_cost_by(metric_rollup_records, hours_in_interval)
+    @hours_in_interval = hours_in_interval
+    metric_value = metric_value_by(metric_rollup_records)
+    [metric_value, hourly_cost(metric_value) * hours_in_interval]
+  end
+
   private
 
   def first_tier?(tier,tiers)