diff --git a/src/main.js b/src/main.js
index f531621..a31127c 100644
--- a/src/main.js
+++ b/src/main.js
@@ -819,10 +819,22 @@ class MiniGraphCard extends LitElement {
 
       // Doesn't matter if minBoundRange is NaN because this will be false if so
       if (diff > 0) {
-        boundary = [
-          boundary[0] - diff / 2,
-          boundary[1] + diff / 2,
+        const weights = [
+          min !== undefined && min[0] !== '~' || max === undefined ? 0 : 1,
+          max !== undefined && max[0] !== '~' || min === undefined ? 0 : 1,
         ];
+        const sum = weights[0] + weights[1];
+        if (sum > 0) {
+          boundary = [
+            boundary[0] - diff * weights[0] / sum,
+            boundary[1] + diff * weights[1] / sum,
+          ];
+        } else {
+          boundary = [
+            boundary[0] - diff / 2,
+            boundary[1] + diff / 2,
+          ];
+        }
       }
     }