diff --git a/src/planscape/impacts/services.py b/src/planscape/impacts/services.py
index 94188454b..0652c3144 100644
--- a/src/planscape/impacts/services.py
+++ b/src/planscape/impacts/services.py
@@ -245,10 +245,14 @@ def generate_impact_results_data_to_plot(
         .annotate(
             value_dividend=Sum(F("value") * F("stand_count")),
             baseline_dividend=Sum(F("baseline") * F("stand_count")),
-            delta_dividend=Sum(F("delta") * F("stand_count")),
+            sum_baselines=Sum("baseline"),
             divisor=Sum("stand_count"),
         )
         .annotate(
+            delta=Case(
+                When(sum_baselines=0, then=None),
+                default=((F("sum_baselines") - Sum("value")) / F("sum_baselines")),
+            ),
             value=Case(
                 When(divisor=0, then=None),
                 default=(F("value_dividend") / F("divisor")),
@@ -257,10 +261,6 @@ def generate_impact_results_data_to_plot(
                 When(divisor=0, then=None),
                 default=(F("baseline_dividend") / F("divisor")),
             ),
-            delta=Case(
-                When(divisor=0, then=None),
-                default=(F("delta_dividend") / F("divisor")),
-            ),
         )
     )
 
@@ -275,7 +275,7 @@ def generate_impact_results_data_to_plot(
     for value in values:
         value.pop("value_dividend")
         value.pop("baseline_dividend")
-        value.pop("delta_dividend")
+        value.pop("sum_baselines")
         value.pop("divisor")
 
     return values
diff --git a/src/planscape/impacts/tests/test_services.py b/src/planscape/impacts/tests/test_services.py
index 3431dfd4d..d7adb67ce 100644
--- a/src/planscape/impacts/tests/test_services.py
+++ b/src/planscape/impacts/tests/test_services.py
@@ -597,7 +597,7 @@ def test_generate_data_to_plot__filter_by_actions(self):
             self.assertIsNotNone(item.get("delta"))
             self.assertIsNone(item.get("value_dividend"))
             self.assertIsNone(item.get("baseline_dividend"))
-            self.assertIsNone(item.get("delta_dividend"))
+            self.assertIsNone(item.get("sum_baselines"))
             self.assertIsNone(item.get("divisor"))
 
     def test_empty_results(self):
@@ -626,6 +626,9 @@ def test_project_area_with_no_treatment(self):
                     aggregation=ImpactVariableAggregation.MEAN,
                     action=None,
                     stand_count=0,
+                    value=0,
+                    baseline=0,
+                    delta=0,
                 )
 
         input_variables = [