diff --git a/app/models/budget.rb b/app/models/budget.rb
index 542e2f5..a9a6edb 100644
--- a/app/models/budget.rb
+++ b/app/models/budget.rb
@@ -41,9 +41,8 @@ class Budget
     return ((self.spent / self.budget) * 100).round
   end
   
-  # TODO
   def spent
-    0
+    self.deliverables.collect(&:spent).inject { |sum, n| sum + n }
   end
   
   def left
diff --git a/spec/models/budget_spec.rb b/spec/models/budget_spec.rb
index 4f57fea..12d89ee 100644
--- a/spec/models/budget_spec.rb
+++ b/spec/models/budget_spec.rb
@@ -263,3 +263,18 @@ describe Budget, '.overruns' do
     @budget.overruns.should eql(1500.0)
   end
 end
+
+describe Budget, '.spent' do
+  it 'should be calculated by the total spent of the deliverables' do
+    @deliverable1 = mock_model(HourlyDeliverable, :project_id => @project, :spent => 1000.00)
+    @deliverable2 = mock_model(HourlyDeliverable, :project_id => @project, :spent => 500.00)
+    Deliverable.stub!(:find_all_by_project_id).and_return([@deliverable1, @deliverable2])
+    
+    @project = mock_model(Project)
+    Project.stub!(:find).with(@project.id).and_return(@project)
+    
+    @budget = Budget.new(@project.id)
+
+    @budget.spent.should eql(1500.0)
+  end
+end