diff --git a/src/main.js b/src/main.js
index 43f806d..85bb78c 100644
--- a/src/main.js
+++ b/src/main.js
@@ -276,7 +276,9 @@ class MiniGraphCard extends LitElement {
 
   getEntityState(id) {
     const entityConfig = this.config.entities[id];
-    if (this.config.show.state === 'last') {
+    if (this.config.show.state === 'sum') {
+      return this.points[id].reduce((sum, point) => sum + point[V], 0);
+    } else if (this.config.show.state === 'last') {
       return this.points[id][this.points[id].length - 1][V];
     } else if (entityConfig.attribute) {
       return this.getObjectAttr(this.entity[id].attributes, entityConfig.attribute);