diff --git a/osu.Game.Rulesets.Mania/Difficulty/ManiaPerformanceCalculator.cs b/osu.Game.Rulesets.Mania/Difficulty/ManiaPerformanceCalculator.cs
index e6e3028d62..bebe07cdee 100644
--- a/osu.Game.Rulesets.Mania/Difficulty/ManiaPerformanceCalculator.cs
+++ b/osu.Game.Rulesets.Mania/Difficulty/ManiaPerformanceCalculator.cs
@@ -105,7 +105,7 @@ namespace osu.Game.Rulesets.Mania.Difficulty
 
         private double computeAccuracyValue(double strainValue)
         {
-            double hitWindowGreat = (Beatmap.HitObjects.First().HitWindows.Great / 2 - 0.5) / TimeRate;
+            double hitWindowGreat = Beatmap.HitObjects.First().HitWindows.Great / 2 / TimeRate;
             if (hitWindowGreat <= 0)
                 return 0;
 
diff --git a/osu.Game.Rulesets.Osu/Difficulty/OsuPerformanceCalculator.cs b/osu.Game.Rulesets.Osu/Difficulty/OsuPerformanceCalculator.cs
index ae74f12339..9803ebaf52 100644
--- a/osu.Game.Rulesets.Osu/Difficulty/OsuPerformanceCalculator.cs
+++ b/osu.Game.Rulesets.Osu/Difficulty/OsuPerformanceCalculator.cs
@@ -61,11 +61,11 @@ namespace osu.Game.Rulesets.Osu.Difficulty
             if (mods.Any(m => !m.Ranked))
                 return 0;
 
-            double hitWindowGreat = (Beatmap.HitObjects.First().HitWindows.Great / 2 - 0.5) / TimeRate;
-            double preEmpt = BeatmapDifficulty.DifficultyRange(Beatmap.BeatmapInfo.BaseDifficulty.ApproachRate, 1800, 1200, 450) / TimeRate;
+            double hitWindowGreat = Beatmap.HitObjects.First().HitWindows.Great / 2 / TimeRate;
+            double preEmpt = (int)BeatmapDifficulty.DifficultyRange(Beatmap.BeatmapInfo.BaseDifficulty.ApproachRate, 1800, 1200, 450) / TimeRate;
 
             realApproachRate = preEmpt > 1200 ? (1800 - preEmpt) / 120 : (1200 - preEmpt) / 150 + 5;
-            realOverallDifficulty = (80 - 0.5 - hitWindowGreat) / 6;
+            realOverallDifficulty = (80 - hitWindowGreat) / 6;
 
             // Custom multipliers for NoFail and SpunOut.
             double multiplier = 1.12f; // This is being adjusted to keep the final pp value scaled around what it used to be when changing things
diff --git a/osu.Game.Rulesets.Taiko/Difficulty/TaikoPerformanceCalculator.cs b/osu.Game.Rulesets.Taiko/Difficulty/TaikoPerformanceCalculator.cs
index 9c9cd1f0fb..b1d73fc1ff 100644
--- a/osu.Game.Rulesets.Taiko/Difficulty/TaikoPerformanceCalculator.cs
+++ b/osu.Game.Rulesets.Taiko/Difficulty/TaikoPerformanceCalculator.cs
@@ -94,7 +94,7 @@ namespace osu.Game.Rulesets.Taiko.Difficulty
 
         private double computeAccuracyValue()
         {
-            double hitWindowGreat = (Beatmap.HitObjects.First().HitWindows.Great / 2 - 0.5) / TimeRate;
+            double hitWindowGreat = Beatmap.HitObjects.First().HitWindows.Great / 2 / TimeRate;
             if (hitWindowGreat <= 0)
                 return 0;