diff --git a/EllesmereUIDamageMeters/EllesmereUIDamageMeters.lua b/EllesmereUIDamageMeters/EllesmereUIDamageMeters.lua
index 92cdce4a2..c880a1a1e 100644
--- a/EllesmereUIDamageMeters/EllesmereUIDamageMeters.lua
+++ b/EllesmereUIDamageMeters/EllesmereUIDamageMeters.lua
@@ -996,24 +996,22 @@ local function PhysicalPixels(userValue)
     return value
 end
 
--- Row geometry with both terms on ONE pixel grid. barHeight is stored as a
--- physical pixel count (plain slider), barSpacing in coordinate units (pixel
--- slider), so it carries the UI scale it was set at. Snapping only the height
--- left the stride between two grids and -((i-1) * stride) drifted down the
--- list: a spacing of 1 then rendered as 0px on some rows and 2px on others, at
--- a fractional UI scale and equally at a pixel-perfect one whenever the value
--- had been saved at another scale.
+-- Row geometry with both terms on ONE pixel grid. barHeight and barSpacing are
+-- both coordinate units, like the window width and fonts, so bars keep their
+-- proportion to the window at any UI scale and a shared profile renders the
+-- same relative size for everyone. Both are snapped against the same effective
+-- scale: a stride between two grids drifts down the list (-((i-1) * stride)),
+-- rendering a spacing of 1 as 0px on some rows and 2px on others.
 -- Returns barH, barSp, stride and one physical pixel, in coordinate units.
-local function RowMetrics(heightPx, spacingCoord, es)
+local function RowMetrics(height, spacingCoord, es)
     local PP = EUI and EUI.PP
     if PP and PP.perfect and PP.SnapForES then
         if not es or es <= 0 then es = (UIParent and UIParent:GetEffectiveScale()) or 1 end
-        local onePixel = PP.perfect / es
-        local barH = PP.SnapForES((heightPx or 18) * onePixel, es)
+        local barH = PP.SnapForES(height or 18, es)
         local barSp = PP.SnapForES(spacingCoord or 2, es)
-        return barH, barSp, barH + barSp, onePixel
+        return barH, barSp, barH + barSp, PP.perfect / es
     end
-    local barH, barSp = PhysicalPixels(heightPx or 18), spacingCoord or 2
+    local barH, barSp = height or 18, spacingCoord or 2
     return barH, barSp, barH + barSp, (PP and PP.mult) or 1
 end
 -- On ns as well: CreateDMWindow sits at Lua 5.1's 60-upvalue cap, so its call
diff --git a/EllesmereUIDamageMeters/EllesmereUIDamageMeters_SpellHistory.lua b/EllesmereUIDamageMeters/EllesmereUIDamageMeters_SpellHistory.lua
index c5a730c1b..38a91e561 100644
--- a/EllesmereUIDamageMeters/EllesmereUIDamageMeters_SpellHistory.lua
+++ b/EllesmereUIDamageMeters/EllesmereUIDamageMeters_SpellHistory.lua
@@ -112,14 +112,12 @@ local function SetFont(fs, size)
     fs:SetFont(font, size, flags)
 end
 
--- Snapped through PP.Scale so accumulated row offsets (stride * index) don't drift off the pixel
--- grid from float dust -- without this, a spacing of 1 can round to 0px on some rows and 2px on others.
-local function PhysicalPixels(val)
+-- Icon size is a coordinate value like the window width and icon spacing, so it
+-- keeps its proportion at any UI scale; only snapped onto the pixel grid.
+local function SnapSize(val)
     local PP = EUI and EUI.PP
-    local mult = (PP and PP.mult) or 1
-    local value = (val or 0) * mult
-    if PP and PP.Scale then return PP.Scale(value) end
-    return value
+    if PP and PP.Snap then return PP.Snap(val or 0) end
+    return val or 0
 end
 
 local function GetBarTexturePath()
@@ -485,7 +483,7 @@ local ANIM_SLIDE_PX = 6
 -- the history length or growth direction never makes the row wander.
 local function IconStripGeometry(count)
     local sh = DB()
-    local iconSz = PhysicalPixels(sh.iconSize or 24)
+    local iconSz = SnapSize(sh.iconSize or 24)
     local gap = sh.iconSpacing or 1
     local dir = sh.growDirection or "LEFT"
     count = max(1, count or sh.iconCount or 5)
@@ -807,7 +805,7 @@ BuildIconStrip = function()
         -- during animation. No strip-level background needed.
     end
 
-    local iconSz = PhysicalPixels(sh.iconSize or 24)
+    local iconSz = SnapSize(sh.iconSize or 24)
     local gap = sh.iconSpacing or 1
     local dir = sh.growDirection or "LEFT"
     local iconZoom = sh.iconZoom or 0.08
diff --git a/EllesmereUI_Migration.lua b/EllesmereUI_Migration.lua
index 5477c0fbe..9c709930b 100644
--- a/EllesmereUI_Migration.lua
+++ b/EllesmereUI_Migration.lua
@@ -4226,3 +4226,63 @@ EllesmereUI.RegisterMigration({
         strip(ctx.profile.condOverrides)
     end,
 })
+
+-- Damage Meters barHeight and Spell History shBarHeight/iconSize now render in UI
+-- units instead of physical pixels (value * perfect / ppUIScale, UIParent-parented
+-- frames). Multiply by that factor once so existing profiles keep their exact size.
+-- GLOBAL on purpose: a profile stamp rides exports, so an old string would get the
+-- RECIPIENT's factor frozen in; imports after this ran are read as UI units.
+-- Per-profile stamps keep it idempotent when a full-account import resets flags.
+EllesmereUI.RegisterMigration({
+    id          = "dm_bar_height_ui_units_v1",
+    scope       = "global",
+    description = "Convert Damage Meters bar height and Spell History bar height/icon size from physical pixels to UI units, keeping every existing profile's rendered size.",
+    body        = function(ctx)
+        local ID = "dm_bar_height_ui_units_v1"
+        local db = ctx.db
+        if not db or type(db.profiles) ~= "table" then return end
+        -- No stamp without the real factor: an error retries next session
+        -- (Startup seeds ppUIScale at login).
+        local _, physH = GetPhysicalScreenSize()
+        if type(physH) ~= "number" or physH <= 0 then error("physical screen size not available") end
+        local uiScale = db.ppUIScale
+        if type(uiScale) ~= "number" or uiScale <= 0 then error("ppUIScale not set yet") end
+        -- Same legacy normalization EllesmereUI_Startup applies before SetScale.
+        if uiScale == 0.53 then uiScale = 0.5333333333
+        elseif uiScale == 0.71 then uiScale = 0.7111111111 end
+        local factor = (768 / physH) / uiScale
+        -- Within 1% the 40px slider maximum moves by under half a pixel, so the
+        -- snapped size is identical: pixel-perfect setups keep their values as-is.
+        local convert = math.abs(factor - 1) > 0.01
+        local function conv(v, default)
+            local n = type(v) == "number" and v or default
+            return floor(n * factor * 10000 + 0.5) / 10000
+        end
+        for _, profData in pairs(db.profiles) do
+            if type(profData) == "table" then
+                local stamps = profData._migrations
+                if type(stamps) ~= "table" then
+                    stamps = {}
+                    profData._migrations = stamps
+                end
+                if not stamps[ID] then
+                    -- Folder present = DM ran in this profile; dm itself is
+                    -- missing when every value was a stripped default.
+                    local addon = convert and type(profData.addons) == "table"
+                        and profData.addons.EllesmereUIDamageMeters
+                    if type(addon) == "table" then
+                        if type(addon.dm) ~= "table" then addon.dm = {} end
+                        local dm = addon.dm
+                        dm.barHeight = conv(dm.barHeight, 18)
+                        local sh = dm.spellHistory
+                        if type(sh) == "table" then
+                            sh.shBarHeight = conv(sh.shBarHeight, 20)
+                            sh.iconSize    = conv(sh.iconSize, 36)
+                        end
+                    end
+                    stamps[ID] = true
+                end
+            end
+        end
+    end,
+})