diff --git a/app/src/main/java/com/placeholder/ringhealth/core/common/Formatters.kt b/app/src/main/java/com/placeholder/ringhealth/core/common/Formatters.kt
new file mode 100644
index 0000000..776d2dc
--- /dev/null
+++ b/app/src/main/java/com/placeholder/ringhealth/core/common/Formatters.kt
@@ -0,0 +1,55 @@
+package com.placeholder.ringhealth.core.common
+
+import androidx.annotation.StringRes
+import com.placeholder.ringhealth.R
+import java.text.SimpleDateFormat
+import java.util.Date
+import java.util.Locale
+
+/** 步数：千分位，如 8,426。 */
+fun formatSteps(steps: Int): String = String.format(Locale.CHINA, "%,d", steps)
+
+/** 距离：保留两位小数（单位 km 由 UI 单独展示）。 */
+fun formatDistance(km: Double): String = String.format(Locale.CHINA, "%.2f", km)
+
+/** 卡路里：只做千分位，单位「千卡」由 UI 用字符串资源拼接（ledger Ruling R13）。 */
+fun formatCalories(kcal: Int): String = String.format(Locale.CHINA, "%,d", kcal)
+
+/** 睡眠时长：7小时32分 / 45分 / 8小时。 */
+fun formatSleepDuration(minutes: Int): String {
+    val hours = minutes / 60
+    val mins = minutes % 60
+    return when {
+        hours > 0 && mins > 0 -> "${hours}小时${mins}分"
+        hours > 0 -> "${hours}小时"
+        else -> "${mins}分"
+    }
+}
+
+/** 运动时长：1小时05分 / 42分（分钟补零）。 */
+fun formatDuration(minutes: Int): String {
+    val hours = minutes / 60
+    val mins = minutes % 60
+    return if (hours > 0) {
+        String.format(Locale.CHINA, "%d小时%02d分", hours, mins)
+    } else {
+        "${mins}分"
+    }
+}
+
+/** 时间戳 → HH:mm。 */
+fun formatClock(timestamp: Long): String =
+    SimpleDateFormat("HH:mm", Locale.CHINA).format(Date(timestamp))
+
+/** 时间戳 → yyyy-MM-dd。 */
+fun formatDate(timestamp: Long): String =
+    SimpleDateFormat("yyyy-MM-dd", Locale.CHINA).format(Date(timestamp))
+
+/** 压力值 → 字符串资源 id。中文描述的唯一来源是 `strings.xml`（ledger Ruling R13）。 */
+@StringRes
+fun stressLevelLabelRes(stress: Int): Int = when {
+    stress < 30 -> R.string.stress_relaxed
+    stress < 60 -> R.string.stress_normal
+    stress < 80 -> R.string.stress_medium
+    else -> R.string.stress_high
+}
diff --git a/app/src/main/res/values/strings.xml b/app/src/main/res/values/strings.xml
index f9a56a6..fa4e8ff 100644
--- a/app/src/main/res/values/strings.xml
+++ b/app/src/main/res/values/strings.xml
@@ -1,4 +1,9 @@
 <?xml version="1.0" encoding="utf-8"?>
 <resources>
     <string name="app_name">RingHealth</string>
+
+    <string name="stress_relaxed">放松</string>
+    <string name="stress_normal">正常</string>
+    <string name="stress_medium">中等</string>
+    <string name="stress_high">偏高</string>
 </resources>
diff --git a/app/src/test/java/com/placeholder/ringhealth/core/common/FormattersTest.kt b/app/src/test/java/com/placeholder/ringhealth/core/common/FormattersTest.kt
new file mode 100644
index 0000000..05a1b00
--- /dev/null
+++ b/app/src/test/java/com/placeholder/ringhealth/core/common/FormattersTest.kt
@@ -0,0 +1,49 @@
+package com.placeholder.ringhealth.core.common
+
+import com.placeholder.ringhealth.R
+import org.junit.Assert.assertEquals
+import org.junit.Test
+
+class FormattersTest {
+
+    @Test
+    fun `formatSleepDuration 处理小时与分钟`() {
+        assertEquals("7小时32分", formatSleepDuration(452))
+        assertEquals("45分", formatSleepDuration(45))
+        assertEquals("8小时", formatSleepDuration(480))
+        assertEquals("0分", formatSleepDuration(0))
+    }
+
+    @Test
+    fun `formatDuration 处理小时与分钟`() {
+        assertEquals("1小时05分", formatDuration(65))
+        assertEquals("42分", formatDuration(42))
+    }
+
+    @Test
+    fun `formatSteps 添加千分位`() {
+        assertEquals("8,426", formatSteps(8426))
+        assertEquals("0", formatSteps(0))
+        assertEquals("1,234,567", formatSteps(1234567))
+    }
+
+    @Test
+    fun `formatDistance 保留两位小数`() {
+        assertEquals("6.21", formatDistance(6.212))
+        assertEquals("0.00", formatDistance(0.0))
+    }
+
+    @Test
+    fun `formatCalories 只返回千分位数字`() {
+        assertEquals("327", formatCalories(327))
+        assertEquals("1,234", formatCalories(1234))
+    }
+
+    @Test
+    fun `stressLevelLabelRes 按区间映射到对应字符串资源`() {
+        assertEquals(R.string.stress_relaxed, stressLevelLabelRes(20))
+        assertEquals(R.string.stress_normal, stressLevelLabelRes(45))
+        assertEquals(R.string.stress_medium, stressLevelLabelRes(65))
+        assertEquals(R.string.stress_high, stressLevelLabelRes(90))
+    }
+}