diff --git a/assets/js/app.ts b/assets/js/app.ts
index abfe6f97..b1620dd0 100644
--- a/assets/js/app.ts
+++ b/assets/js/app.ts
@@ -127,8 +127,10 @@ const SensorChart: SensorChartHook = {
     if (autoScale) {
       if (showZeroLine && unit === 'bps') {
         // Find max absolute value to make symmetric scale
+        // Exclude capacity reference lines so they don't dominate the scale
         let maxAbsValue = 0
         datasets.forEach(dataset => {
+          if (dataset.label?.startsWith('Capacity')) return
           if (dataset.data && dataset.data.length > 0) {
             dataset.data.forEach((point: ChartDataPoint) => {
               if (point && typeof point.y === 'number') {