diff --git a/app/src/main/java/org/mozilla/fenix/perf/Stat.kt b/app/src/main/java/org/mozilla/fenix/perf/Stat.kt
new file mode 100644
index 0000000000..a2ff22b53b
--- /dev/null
+++ b/app/src/main/java/org/mozilla/fenix/perf/Stat.kt
@@ -0,0 +1,66 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+package org.mozilla.fenix.perf
+
+import android.os.SystemClock
+import android.system.Os
+import android.system.OsConstants
+import androidx.annotation.VisibleForTesting
+import androidx.annotation.VisibleForTesting.PRIVATE
+import java.io.File
+import java.util.concurrent.TimeUnit
+
+private const val FIELD_POS_STARTTIME = 21 // starttime naming matches field in man page.
+
+/**
+ * Functionality from stat on the proc pseudo-filesystem common to unix systems. /proc contains
+ * information related to active processes. /proc/$pid/stat contains information about the status of
+ * the process by the given process id (pid).
+ *
+ * See the man page - `man 5 proc` - on linux for more information:
+ *   http://man7.org/linux/man-pages/man5/proc.5.html
+ */
+open class Stat {
+
+    @VisibleForTesting(otherwise = PRIVATE)
+    open fun getStatText(pid: Int): String = File("/proc/$pid/stat").readText()
+
+    // See `man 3 sysconf` for details on Os.sysconf and OsConstants:
+    //   http://man7.org/linux/man-pages/man3/sysconf.3.html
+    open val clockTicksPerSecond: Long get() = Os.sysconf(OsConstants._SC_CLK_TCK)
+    private val nanosPerClockTick = TimeUnit.SECONDS.toNanos(1).let { nanosPerSecond ->
+        // We use nanos per clock tick, rather than clock ticks per nanos, to mitigate float/double
+        // rounding errors: this way we can use integer values and divide the larger value by the smaller one.
+        nanosPerSecond / clockTicksPerSecond.toDouble()
+    }
+
+    /**
+     * Gets the process start time since system boot in ticks, including time spent in suspension/deep sleep.
+     * This value can be compared against [SystemClock.elapsedRealtimeNanos]: you can convert between
+     * measurements using [convertTicksToNanos] and [convertNanosToTicks].
+     *
+     * Ticks are "an arbitrary unit for measuring internal system time": https://superuser.com/a/101202
+     * They are not aligned with CPU frequency and do not change at runtime but can theoretically
+     * change between devices. On the Pixel 2, one tick is equivalent to one centisecond.
+     *
+     * We confirmed that this measurement and elapsedRealtimeNanos both include suspension time, and
+     * are thus comparable, by* looking at their source:
+     * - /proc/pid/stat starttime is set using boottime:
+     * https://github.com/torvalds/linux/blob/79e178a57dae819ae724065b47c25720494cc9f2/fs/proc/array.c#L536
+     * - elapsedRealtimeNanos is set using boottime:
+     * https://cs.android.com/android/platform/superproject/+/master:system/core/libutils/SystemClock.cpp;l=60-68;drc=bab16584ce0525742b5370682c9132b2002ee110
+     *
+     * Perf note: this call reads from the pseudo-filesystem using the java File APIs, which isn't
+     * likely to be a very optimized call path.
+     *
+     * Implementation inspired by https://stackoverflow.com/a/42195623.
+     */
+    fun getProcessStartTimeTicks(pid: Int): Long {
+        return getStatText(pid).split(' ')[FIELD_POS_STARTTIME].toLong()
+    }
+
+    fun convertTicksToNanos(ticks: Long): Double = ticks * nanosPerClockTick
+    fun convertNanosToTicks(nanos: Long): Double = nanos / nanosPerClockTick
+}
diff --git a/app/src/test/java/org/mozilla/fenix/perf/StatTest.kt b/app/src/test/java/org/mozilla/fenix/perf/StatTest.kt
new file mode 100644
index 0000000000..aed5e6c71e
--- /dev/null
+++ b/app/src/test/java/org/mozilla/fenix/perf/StatTest.kt
@@ -0,0 +1,45 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+package org.mozilla.fenix.perf
+
+import org.junit.Assert.assertEquals
+import org.junit.Before
+import org.junit.Test
+
+private const val STAT_CONTENTS = "32250 (a.fennec_aurora) S 831 831 0 0 -1 1077952832 670949 0 184936 0 15090 5387 0 0 20 0 119 0 166636813 9734365184 24664 18446744073709551615 1 1 0 0 0 0 4612 4097 1073792254 0 0 0 17 1 0 0 0 0 0 0 0 0 0 0 0 0 0"
+private const val CLOCK_TICKS_PER_SECOND = 100L // actual value on the Pixel 2.
+
+class StatTest {
+
+    private lateinit var stat: StatTestImpl
+
+    @Before
+    fun setUp() {
+        stat = StatTestImpl()
+    }
+
+    @Test
+    fun `WHEN getting the process start time THEN the correct value is returned`() {
+        val actual = stat.getProcessStartTimeTicks(pid = -1) // pid behavior is overridden.
+        assertEquals(166636813, actual) // expected value calculated by hand.
+    }
+
+    @Test
+    fun `WHEN converting ticks to nanos THEN the correct value is returned`() {
+        val actual = stat.convertTicksToNanos(166_636_813)
+        assertEquals(1_666_368_130_000_000.0, actual, 0.0) // expected value calculated by hand.
+    }
+
+    @Test
+    fun `WHEN converting nanos to ticks THEN the correct value is returned`() {
+        val actual = stat.convertNanosToTicks(1_666_368_135_432_102)
+        assertEquals(166_636_813.5432102, actual, 0.0) // expected value calculated by hand.
+    }
+}
+
+class StatTestImpl : Stat() {
+    override fun getStatText(pid: Int): String = STAT_CONTENTS
+    override val clockTicksPerSecond: Long get() = CLOCK_TICKS_PER_SECOND
+}