diff --git a/app/src/main/java/org/nsh07/pomodoro/ui/AppScreen.kt b/app/src/main/java/org/nsh07/pomodoro/ui/AppScreen.kt
index 66dc912..300bb95 100644
--- a/app/src/main/java/org/nsh07/pomodoro/ui/AppScreen.kt
+++ b/app/src/main/java/org/nsh07/pomodoro/ui/AppScreen.kt
@@ -4,6 +4,7 @@ import androidx.compose.material3.ExperimentalMaterial3Api
 import androidx.compose.material3.ExperimentalMaterial3ExpressiveApi
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.getValue
+import androidx.compose.runtime.rememberUpdatedState
 import androidx.compose.ui.Modifier
 import androidx.lifecycle.compose.collectAsStateWithLifecycle
 import org.nsh07.pomodoro.ui.timerScreen.TimerScreen
@@ -16,6 +17,15 @@ fun AppScreen(
     modifier: Modifier = Modifier
 ) {
     val uiState by viewModel.uiState.collectAsStateWithLifecycle()
+    val remainingTime by viewModel.time.collectAsStateWithLifecycle()
 
-    TimerScreen(uiState = uiState, resetTimer = viewModel::resetTimer, toggleTimer = viewModel::toggleTimer, modifier = modifier)
+    val progress by rememberUpdatedState((uiState.totalTime.toFloat() - remainingTime) / uiState.totalTime)
+
+    TimerScreen(
+        uiState = uiState,
+        progress = { progress },
+        resetTimer = viewModel::resetTimer,
+        toggleTimer = viewModel::toggleTimer,
+        modifier = modifier
+    )
 }
\ No newline at end of file
diff --git a/app/src/main/java/org/nsh07/pomodoro/ui/timerScreen/TimerScreen.kt b/app/src/main/java/org/nsh07/pomodoro/ui/timerScreen/TimerScreen.kt
index 65ad928..408a3b1 100644
--- a/app/src/main/java/org/nsh07/pomodoro/ui/timerScreen/TimerScreen.kt
+++ b/app/src/main/java/org/nsh07/pomodoro/ui/timerScreen/TimerScreen.kt
@@ -49,6 +49,7 @@ import org.nsh07.pomodoro.ui.viewModel.UiState
 @Composable
 fun TimerScreen(
     uiState: UiState,
+    progress: () -> Float,
     resetTimer: () -> Unit,
     toggleTimer: () -> Unit,
     modifier: Modifier = Modifier
@@ -144,7 +145,7 @@ fun TimerScreen(
             Column(horizontalAlignment = Alignment.CenterHorizontally) {
                 Box(contentAlignment = Alignment.Center) {
                     CircularProgressIndicator(
-                        progress = { (uiState.totalTime.toFloat() - uiState.remainingTime) / uiState.totalTime },
+                        progress =  progress,
                         modifier = Modifier.size(350.dp),
                         color = color,
                         trackColor = colorContainer,
@@ -238,5 +239,5 @@ fun TimerScreenPreview() {
     val uiState = UiState(
         timeStr = "08:34", nextTimeStr = "5:00"
     )
-    TimerScreen(uiState, {}, {})
+    TimerScreen(uiState, { 0.3f }, {}, {})
 }
diff --git a/app/src/main/java/org/nsh07/pomodoro/ui/viewModel/UiState.kt b/app/src/main/java/org/nsh07/pomodoro/ui/viewModel/UiState.kt
index 0bd8415..8e963f2 100644
--- a/app/src/main/java/org/nsh07/pomodoro/ui/viewModel/UiState.kt
+++ b/app/src/main/java/org/nsh07/pomodoro/ui/viewModel/UiState.kt
@@ -4,7 +4,6 @@ data class UiState(
     val timerMode: TimerMode = TimerMode.FOCUS,
     val timeStr: String = "25:00",
     val totalTime: Int = 25 * 60,
-    val remainingTime: Int = 25 * 60,
     val timerRunning: Boolean = false,
     val nextTimerMode: TimerMode = TimerMode.SHORT_BREAK,
     val nextTimeStr: String = "5:00"
diff --git a/app/src/main/java/org/nsh07/pomodoro/ui/viewModel/UiViewModel.kt b/app/src/main/java/org/nsh07/pomodoro/ui/viewModel/UiViewModel.kt
index 17f1214..3db5ed4 100644
--- a/app/src/main/java/org/nsh07/pomodoro/ui/viewModel/UiViewModel.kt
+++ b/app/src/main/java/org/nsh07/pomodoro/ui/viewModel/UiViewModel.kt
@@ -12,36 +12,36 @@ import kotlinx.coroutines.launch
 import java.util.Locale
 
 class UiViewModel : ViewModel() {
-    val focusTime = 10
-    val shortBreakTime = 5
-    val longBreakTime = 20
+    val focusTime = 10000
+    val shortBreakTime = 5000
+    val longBreakTime = 20000
 
     private val _uiState = MutableStateFlow(
         UiState(
             totalTime = focusTime,
-            remainingTime = focusTime,
-            timeStr = secondsToStr(focusTime),
-            nextTimeStr = secondsToStr(shortBreakTime)
+            timeStr = millisecondsToStr(focusTime),
+            nextTimeStr = millisecondsToStr(shortBreakTime)
         )
     )
     val uiState: StateFlow<UiState> = _uiState.asStateFlow()
     var timerJob: Job? = null
 
-    var time = focusTime
+    private val _time = MutableStateFlow(focusTime)
+    val time: StateFlow<Int> = _time.asStateFlow()
+
     var cycles = 0
 
     fun resetTimer() {
-        time = focusTime
+        _time.update {  focusTime }
         cycles = 0
 
         _uiState.update { currentState ->
             currentState.copy(
                 timerMode = TimerMode.FOCUS,
-                timeStr = secondsToStr(time),
-                totalTime = time,
-                remainingTime = time,
+                timeStr = millisecondsToStr(time.value),
+                totalTime = time.value,
                 nextTimerMode = TimerMode.SHORT_BREAK,
-                nextTimeStr = secondsToStr(shortBreakTime)
+                nextTimeStr = millisecondsToStr(shortBreakTime)
             )
         }
     }
@@ -57,58 +57,55 @@ class UiViewModel : ViewModel() {
             timerJob = viewModelScope.launch {
                 while (true) {
                     if (!uiState.value.timerRunning) break
-                    time--
+                    _time.update { it - 10 }
 
-                    if (time < 0) {
+                    if (time.value < 0) {
                         cycles++
 
                         if (cycles % 2 == 0) {
-                            time = focusTime
+                            _time.update {  focusTime }
                             _uiState.update { currentState ->
                                 currentState.copy(
                                     timerMode = TimerMode.FOCUS,
-                                    timeStr = secondsToStr(time),
-                                    totalTime = time,
-                                    remainingTime = time,
+                                    timeStr = millisecondsToStr(time.value),
+                                    totalTime = time.value,
                                     nextTimerMode = if (cycles % 6 == 0) TimerMode.LONG_BREAK else TimerMode.SHORT_BREAK,
-                                    nextTimeStr = if (cycles % 6 == 0) secondsToStr(longBreakTime) else secondsToStr(
+                                    nextTimeStr = if (cycles % 6 == 0) millisecondsToStr(longBreakTime) else millisecondsToStr(
                                         shortBreakTime
                                     )
                                 )
                             }
                         } else {
                             val long = cycles % 7 == 0
-                            time = if (long) longBreakTime else shortBreakTime
+                            _time.update {  if (long) longBreakTime else shortBreakTime }
 
                             _uiState.update { currentState ->
                                 currentState.copy(
                                     timerMode = if (long) TimerMode.LONG_BREAK else TimerMode.SHORT_BREAK,
-                                    timeStr = secondsToStr(time),
-                                    totalTime = time,
-                                    remainingTime = time,
+                                    timeStr = millisecondsToStr(time.value),
+                                    totalTime = time.value,
                                     nextTimerMode = TimerMode.FOCUS,
-                                    nextTimeStr = secondsToStr(focusTime)
+                                    nextTimeStr = millisecondsToStr(focusTime)
                                 )
                             }
                         }
                     } else {
                         _uiState.update { currentState ->
                             currentState.copy(
-                                timeStr = secondsToStr(time),
-                                remainingTime = time
+                                timeStr = millisecondsToStr(time.value)
                             )
                         }
                     }
 
-                    delay(1000)
+                    delay(10)
                 }
             }
         }
     }
 
-    private fun secondsToStr(t: Int): String {
-        val min = t / 60
-        val sec = t % 60
+    private fun millisecondsToStr(t: Int): String {
+        val min = (t / 1000) / 60
+        val sec = (t / 1000) % 60
         return String.format(locale = Locale.getDefault(), "%02d:%02d", min, sec)
     }
 }
\ No newline at end of file