diff --git a/scripts/components/volforceCalc.lua b/scripts/components/volforceCalc.lua
new file mode 100644
index 0000000..e1047da
--- /dev/null
+++ b/scripts/components/volforceCalc.lua
@@ -0,0 +1,44 @@
+-- force calculation
+--------------------
+totalForce = nil
+
+local badgeRates = {
+	0.5,  -- Played
+	1.0,  -- Cleared
+	1.02, -- Hard clear
+	1.04, -- UC
+	1.1   -- PUC
+}
+
+local gradeRates = {
+	{["min"] = 9900000, ["rate"] = 1.05}, -- S
+	{["min"] = 9800000, ["rate"] = 1.02}, -- AAA+
+	{["min"] = 9700000, ["rate"] = 1},    -- AAA
+	{["min"] = 9500000, ["rate"] = 0.97}, -- AA+
+	{["min"] = 9300000, ["rate"] = 0.94}, -- AA
+	{["min"] = 9000000, ["rate"] = 0.91}, -- A+
+	{["min"] = 8700000, ["rate"] = 0.88}, -- A
+	{["min"] = 7500000, ["rate"] = 0.85}, -- B
+	{["min"] = 6500000, ["rate"] = 0.82}, -- C
+	{["min"] =       0, ["rate"] = 0.8}   -- D
+}
+
+calculate_force = function(diff)
+	if #diff.scores < 1 then
+		return 0
+	end
+	local score = diff.scores[1]
+	local badgeRate = badgeRates[diff.topBadge]
+	local gradeRate
+    for i, v in ipairs(gradeRates) do
+      if score.score >= v.min then
+        gradeRate = v.rate
+		break
+      end
+    end
+	return math.floor((diff.level * 2) * (score.score / 10000000) * gradeRate * badgeRate) / 100
+end
+
+return {
+    calc = calculate_force
+}
\ No newline at end of file
diff --git a/scripts/components/volforceWindow.lua b/scripts/components/volforceWindow.lua
new file mode 100644
index 0000000..432132f
--- /dev/null
+++ b/scripts/components/volforceWindow.lua
@@ -0,0 +1,24 @@
+
+
+local volforceBadgeImage = gfx.CreateSkinImage("volforce/10.png", 0);
+
+function render(deltatime, x, y)
+    gfx.LoadSkinFont('Digital-Serial-Bold.ttf')
+    gfx.TextAlign(gfx.TEXT_ALIGN_LEFT + gfx.TEXT_ALIGN_MIDDLE)
+
+    local volforceAmount = game.GetSkinSetting('_volforce') or 0;
+
+    -- Draw volforce badge
+    gfx.BeginPath();
+    gfx.ImageRect(x, y, 42, 42, volforceBadgeImage, 1, 0);
+
+    -- Draw volforce label
+    gfx.FontSize(11)
+    gfx.Text('VOLFORCE', x + 47, y + 14);
+    gfx.FontSize(18)
+    gfx.Text(string.format('%.3f', volforceAmount), x + 47, y + 30);
+end
+
+return {
+    render = render
+}
\ No newline at end of file
diff --git a/scripts/result.lua b/scripts/result.lua
index d5054ed..fa52518 100644
--- a/scripts/result.lua
+++ b/scripts/result.lua
@@ -1,6 +1,8 @@
 local Easing = require('common.easings');
 local Footer = require('components.footer');
 
+local VolforceWindow = require('components.volforceWindow')
+
 local resx, resy = game.GetResolution()
 local desw = 1080
 local desh = 1920
@@ -312,7 +314,7 @@ local drawBottomPanel = function()
                   bottomPanelImage, 1, 0);
 end
 
-local drawBottomPanelContent = function ()
+local drawBottomPanelContent = function (deltatime)
     -- Draw appeal card
     gfx.BeginPath();
     gfx.ImageRect(bottomPanelX+58, bottomPanelY+277, 103, 132, appealCardImage, 1, 0);
@@ -331,15 +333,8 @@ local drawBottomPanelContent = function ()
     gfx.BeginPath();
     gfx.ImageRect(bottomPanelX+187, bottomPanelY+362, 107, 29, danBadgeImage, 1, 0);
     
-    -- Draw volforce badge
-    gfx.BeginPath();
-    gfx.ImageRect(bottomPanelX+310, bottomPanelY+355, 42, 42, volforceBadgeImage, 1, 0);
-
-    -- Draw volforce label
-    gfx.FontSize(11)
-    gfx.Text('VOLFORCE', bottomPanelX+357, bottomPanelY+369);
-    gfx.FontSize(18)
-    gfx.Text('20.148', bottomPanelX+357, bottomPanelY+385);
+    -- Draw volforce
+    VolforceWindow.render(0, bottomPanelX+310, bottomPanelY+355)
 end
 
 local drawJacketPanel = function()
@@ -471,7 +466,7 @@ render = function(deltaTime, showStats)
     gfx.GlobalAlpha(Easing.outQuad(transitionEnterScale))
 
     drawBottomPanel()
-    drawBottomPanelContent()
+    drawBottomPanelContent(deltaTime)
 
     drawRightPanel()
     drawRightPanelContent()
diff --git a/scripts/songselect/songwheel.lua b/scripts/songselect/songwheel.lua
index 54223cb..22b8820 100644
--- a/scripts/songselect/songwheel.lua
+++ b/scripts/songselect/songwheel.lua
@@ -1,6 +1,8 @@
 require('common')
 local Easing = require('common.easings');
 
+local VolforceCalc = require('components.volforceCalc');
+
 local backgroundImage = gfx.CreateSkinImage("song_select/bg.png", 1)
 local dataPanelImage = gfx.CreateSkinImage("song_select/data_bg_overlay.png", 1)
 local dataGlowOverlayImage = gfx.CreateSkinImage("song_select/data_panel/data_glow_overlay.png", 1)
@@ -571,6 +573,31 @@ render = function (deltaTime)
     gfx.Text('S_I: ' .. selectedIndex .. ' // S_D: ' .. selectedDifficulty .. ' // S_UP: ' .. debugScrollingUp .. ' // AC_TS: ' .. transitionAfterscrollScale, 8, 8);
 end
 
+songs_changed = function (withAll)
+    if not withAll then return end
+
+	local diffs = {}
+	for i = 1, #songwheel.allSongs do
+		local song = songwheel.allSongs[i]
+		for j = 1, #song.difficulties do
+			local diff = song.difficulties[j]
+			diff.force = VolforceCalc.calc(diff)
+			table.insert(diffs, diff)
+		end
+	end
+	table.sort(diffs, function (l, r)
+		return l.force > r.force
+	end)
+	totalForce = 0
+	for i = 1, 50 do
+		if diffs[i] then
+			totalForce = totalForce + diffs[i].force
+		end
+	end
+
+    game.SetSkinSetting('_volforce', totalForce)
+end
+
 set_index = function(newIndex)
     transitionScrollScale = 0;
     transitionAfterscrollScale = 0;