diff --git a/app/src/main/java/com/laseroptek/raman/ui/screens/home/dcd/DcdSettingPopup.kt b/app/src/main/java/com/laseroptek/raman/ui/screens/home/dcd/DcdSettingPopup.kt
index 359e05f..5bd631c 100644
--- a/app/src/main/java/com/laseroptek/raman/ui/screens/home/dcd/DcdSettingPopup.kt
+++ b/app/src/main/java/com/laseroptek/raman/ui/screens/home/dcd/DcdSettingPopup.kt
@@ -334,7 +334,7 @@ fun DcdSettingPopup(
                         modifier = Modifier
                             .fillMaxHeight()
                             .size(40.px.dp, 210.px.dp),
-                        chargeRate = gasChargeRate.toInt()
+                        chargeRate = gasChargeRate
                     )
 
                     // Icon
diff --git a/app/src/main/java/com/laseroptek/raman/ui/screens/home/dcd/GradientSlider.kt b/app/src/main/java/com/laseroptek/raman/ui/screens/home/dcd/GradientSlider.kt
index 3250621..4babb62 100644
--- a/app/src/main/java/com/laseroptek/raman/ui/screens/home/dcd/GradientSlider.kt
+++ b/app/src/main/java/com/laseroptek/raman/ui/screens/home/dcd/GradientSlider.kt
@@ -28,14 +28,26 @@ import com.laseroptek.raman.ui.screens.main.MainViewModel
 import com.laseroptek.raman.utils.DefaultDispatcherProvider
 import com.laseroptek.raman.utils.ext.px
 import timber.log.Timber
+import kotlin.math.abs
+import kotlin.math.ceil
 
 
 @Composable
 fun GradientSlider(
     modifier: Modifier = Modifier,
-    chargeRate: Int = 0, // Value from (0 .. 100)
+    chargeRate: Float = 0f,
 ) {
-    val chargeIndex = ((chargeRate.coerceIn(0, 100) + 4) / 5).toInt()   // 0..19
+    val normalizedRate = chargeRate.coerceIn(0f, 100f)
+    val bucket = normalizedRate / 5f
+    val remainder = normalizedRate % 5f
+    val isExactMultiple = abs(remainder) < 0.0001f
+
+    val chargeIndex = when {
+        normalizedRate == 0f -> -1
+        isExactMultiple -> (bucket - 1f).toInt().coerceAtLeast(-1)
+        else -> (ceil(bucket.toDouble()).toInt() - 1)
+    }.coerceIn(-1, 19)
+
     Timber.d("chargeRate: $chargeRate, chargeIndex: $chargeIndex")
 
     Box(
@@ -103,6 +115,6 @@ fun GradientSliderPreview(
         //mainViewModel = mainViewModel
         modifier = Modifier
             .size(40.px.dp, 210.px.dp),
-        chargeRate =  20
+        chargeRate = 20f
     )
 }