diff --git a/osu.Game.Tests/Visual/UserInterface/TestSceneSegmentedGraph.cs b/osu.Game.Tests/Visual/UserInterface/TestSceneSegmentedGraph.cs
index 1144b9053d..320ec48e07 100644
--- a/osu.Game.Tests/Visual/UserInterface/TestSceneSegmentedGraph.cs
+++ b/osu.Game.Tests/Visual/UserInterface/TestSceneSegmentedGraph.cs
@@ -7,6 +7,7 @@ using System.Diagnostics;
 using System.Linq;
 using osu.Framework.Graphics;
 using osu.Framework.Graphics.Colour;
+using osu.Game.Beatmaps;
 using osu.Game.Graphics.UserInterface;
 using osu.Game.Rulesets.Objects;
 using osu.Game.Rulesets.Osu;
@@ -137,8 +138,7 @@ namespace osu.Game.Tests.Visual.UserInterface
             if (!objects.Any())
                 return;
 
-            double firstHit = objects.First().StartTime;
-            double lastHit = objects.Max(o => o.GetEndTime());
+            (double firstHit, double lastHit) = BeatmapExtensions.CalculatePlayableBounds(objects);
 
             if (lastHit == 0)
                 lastHit = objects.Last().StartTime;
diff --git a/osu.Game/Beatmaps/BeatmapUpdater.cs b/osu.Game/Beatmaps/BeatmapUpdater.cs
index af9f32f834..046adb8327 100644
--- a/osu.Game/Beatmaps/BeatmapUpdater.cs
+++ b/osu.Game/Beatmaps/BeatmapUpdater.cs
@@ -3,7 +3,6 @@
 
 using System;
 using System.Diagnostics;
-using System.Linq;
 using System.Threading.Tasks;
 using osu.Framework.Extensions.ObjectExtensions;
 using osu.Framework.Logging;
@@ -11,7 +10,6 @@ using osu.Framework.Platform;
 using osu.Framework.Threading;
 using osu.Game.Database;
 using osu.Game.Online.API;
-using osu.Game.Rulesets.Objects;
 
 namespace osu.Game.Beatmaps
 {
@@ -74,7 +72,7 @@ namespace osu.Game.Beatmaps
                 var calculator = ruleset.CreateDifficultyCalculator(working);
 
                 beatmap.StarRating = calculator.Calculate().StarRating;
-                beatmap.Length = calculateLength(working.Beatmap);
+                beatmap.Length = working.Beatmap.CalculatePlayableLength();
                 beatmap.BPM = 60000 / working.Beatmap.GetMostCommonBeatLength();
             }
 
@@ -82,20 +80,6 @@ namespace osu.Game.Beatmaps
             workingBeatmapCache.Invalidate(beatmapSet);
         });
 
-        private double calculateLength(IBeatmap b)
-        {
-            if (!b.HitObjects.Any())
-                return 0;
-
-            var lastObject = b.HitObjects.Last();
-
-            //TODO: this isn't always correct (consider mania where a non-last object may last for longer than the last in the list).
-            double endTime = lastObject.GetEndTime();
-            double startTime = b.HitObjects.First().StartTime;
-
-            return endTime - startTime;
-        }
-
         #region Implementation of IDisposable
 
         public void Dispose()
diff --git a/osu.Game/Beatmaps/IBeatmap.cs b/osu.Game/Beatmaps/IBeatmap.cs
index f6771f7adf..9dc3084cb5 100644
--- a/osu.Game/Beatmaps/IBeatmap.cs
+++ b/osu.Game/Beatmaps/IBeatmap.cs
@@ -104,6 +104,19 @@ namespace osu.Game.Beatmaps
             }
         }
 
+        /// <summary>
+        /// Find the total milliseconds between the first and last hittable objects.
+        /// </summary>
+        /// <remarks>
+        /// This is cached to <see cref="BeatmapInfo.Length"/>, so using that is preferable when available.
+        /// </remarks>
+        public static double CalculatePlayableLength(this IBeatmap beatmap) => CalculatePlayableLength(beatmap.HitObjects);
+
+        /// <summary>
+        /// Find the timestamps in milliseconds of the start and end of the playable region.
+        /// </summary>
+        public static (double start, double end) CalculatePlayableBounds(this IBeatmap beatmap) => CalculatePlayableBounds(beatmap.HitObjects);
+
         /// <summary>
         /// Find the absolute end time of the latest <see cref="HitObject"/> in a beatmap. Will throw if beatmap contains no objects.
         /// </summary>
@@ -114,5 +127,36 @@ namespace osu.Game.Beatmaps
         /// It's not super efficient so calls should be kept to a minimum.
         /// </remarks>
         public static double GetLastObjectTime(this IBeatmap beatmap) => beatmap.HitObjects.Max(h => h.GetEndTime());
+
+        #region Helper methods
+
+        /// <summary>
+        /// Find the total milliseconds between the first and last hittable objects.
+        /// </summary>
+        /// <remarks>
+        /// This is cached to <see cref="BeatmapInfo.Length"/>, so using that is preferable when available.
+        /// </remarks>
+        public static double CalculatePlayableLength(IEnumerable<HitObject> objects)
+        {
+            (double start, double end) = CalculatePlayableBounds(objects);
+
+            return end - start;
+        }
+
+        /// <summary>
+        /// Find the timestamps in milliseconds of the start and end of the playable region.
+        /// </summary>
+        public static (double start, double end) CalculatePlayableBounds(IEnumerable<HitObject> objects)
+        {
+            if (!objects.Any())
+                return (0, 0);
+
+            double lastObjectTime = objects.Max(o => o.GetEndTime());
+            double firstObjectTime = objects.First().StartTime;
+
+            return (firstObjectTime, lastObjectTime);
+        }
+
+        #endregion
     }
 }
diff --git a/osu.Game/Screens/Play/HUD/ArgonSongProgressGraph.cs b/osu.Game/Screens/Play/HUD/ArgonSongProgressGraph.cs
index 0899476ed4..63ab9d15e0 100644
--- a/osu.Game/Screens/Play/HUD/ArgonSongProgressGraph.cs
+++ b/osu.Game/Screens/Play/HUD/ArgonSongProgressGraph.cs
@@ -5,6 +5,7 @@ using System.Collections.Generic;
 using System.Diagnostics;
 using System.Linq;
 using osu.Framework.Graphics;
+using osu.Game.Beatmaps;
 using osu.Game.Rulesets.Objects;
 using osu.Game.Graphics.UserInterface;
 
@@ -26,8 +27,7 @@ namespace osu.Game.Screens.Play.HUD
                 if (!objects.Any())
                     return;
 
-                double firstHit = objects.First().StartTime;
-                double lastHit = objects.Max(o => o.GetEndTime());
+                (double firstHit, double lastHit) = BeatmapExtensions.CalculatePlayableBounds(objects);
 
                 if (lastHit == 0)
                     lastHit = objects.Last().StartTime;
diff --git a/osu.Game/Screens/Play/HUD/DefaultSongProgressGraph.cs b/osu.Game/Screens/Play/HUD/DefaultSongProgressGraph.cs
index bee5978817..047c64a4a4 100644
--- a/osu.Game/Screens/Play/HUD/DefaultSongProgressGraph.cs
+++ b/osu.Game/Screens/Play/HUD/DefaultSongProgressGraph.cs
@@ -6,6 +6,7 @@
 using System.Linq;
 using System.Collections.Generic;
 using System.Diagnostics;
+using osu.Game.Beatmaps;
 using osu.Game.Rulesets.Objects;
 
 namespace osu.Game.Screens.Play.HUD
@@ -26,8 +27,7 @@ namespace osu.Game.Screens.Play.HUD
                 if (!objects.Any())
                     return;
 
-                double firstHit = objects.First().StartTime;
-                double lastHit = objects.Max(o => o.GetEndTime());
+                (double firstHit, double lastHit) = BeatmapExtensions.CalculatePlayableBounds(objects);
 
                 if (lastHit == 0)
                     lastHit = objects.Last().StartTime;
diff --git a/osu.Game/Screens/Play/HUD/SongProgress.cs b/osu.Game/Screens/Play/HUD/SongProgress.cs
index ebe2fb83e6..4391193df8 100644
--- a/osu.Game/Screens/Play/HUD/SongProgress.cs
+++ b/osu.Game/Screens/Play/HUD/SongProgress.cs
@@ -2,12 +2,12 @@
 // See the LICENCE file in the repository root for full licence text.
 
 using System.Collections.Generic;
-using System.Linq;
 using osu.Framework.Allocation;
 using osu.Framework.Bindables;
 using osu.Framework.Graphics;
 using osu.Framework.Graphics.Containers;
 using osu.Framework.Timing;
+using osu.Game.Beatmaps;
 using osu.Game.Rulesets.Objects;
 using osu.Game.Rulesets.UI;
 using osu.Game.Skinning;
@@ -52,9 +52,9 @@ namespace osu.Game.Screens.Play.HUD
             set
             {
                 objects = value;
-                FirstHitTime = objects.FirstOrDefault()?.StartTime ?? 0;
-                //TODO: this isn't always correct (consider mania where a non-last object may last for longer than the last in the list).
-                LastHitTime = objects.LastOrDefault()?.GetEndTime() ?? 0;
+
+                (FirstHitTime, LastHitTime) = BeatmapExtensions.CalculatePlayableBounds(objects);
+
                 UpdateObjects(objects);
             }
         }