diff --git a/apps/desktop/src/app/chat/composer/controls.tsx b/apps/desktop/src/app/chat/composer/controls.tsx
index 364ee6d3b83..8bc7abc4acc 100644
--- a/apps/desktop/src/app/chat/composer/controls.tsx
+++ b/apps/desktop/src/app/chat/composer/controls.tsx
@@ -4,7 +4,7 @@ import { KbdCombo } from '@/components/ui/kbd'
 import { Tip } from '@/components/ui/tooltip'
 import { useI18n } from '@/i18n'
 import { triggerHaptic } from '@/lib/haptics'
-import { AudioLines, Layers3, Loader2, Square, SteeringWheel, Volume2, VolumeX } from '@/lib/icons'
+import { AudioLines, iconSize, Layers3, Loader2, Square, SteeringWheel, Volume2, VolumeX } from '@/lib/icons'
 import { formatCombo } from '@/lib/keybinds/combo'
 import { cn } from '@/lib/utils'
 
@@ -103,7 +103,7 @@ export function ComposerControls({
             type="button"
             variant="ghost"
           >
-            <SteeringWheel size={14} />
+            <SteeringWheel className={iconSize.sm} />
           </Button>
         </Tip>
       ) : (
@@ -123,7 +123,7 @@ export function ComposerControls({
             size="icon"
             type="button"
           >
-            <AudioLines size={15} />
+            <AudioLines className={iconSize.sm} />
           </Button>
         </Tip>
       ) : (
@@ -136,7 +136,7 @@ export function ComposerControls({
           >
             {busy ? (
               busyAction === 'queue' ? (
-                <Layers3 size={14} />
+                <Layers3 className={iconSize.sm} />
               ) : (
                 <span className="block size-2.5 rounded-[0.1875rem] bg-current" />
               )
@@ -207,7 +207,7 @@ function ConversationPill({
           type="button"
           variant="ghost"
         >
-          <Square className="fill-current" size={11} />
+          <Square className={cn('fill-current', iconSize.xs)} />
           <span>{c.stopShort}</span>
         </Button>
       )}
@@ -242,7 +242,7 @@ function ConversationIndicator({
   speaking: boolean
 }) {
   if (speaking) {
-    return <Loader2 className="animate-spin" size={12} />
+    return <Loader2 className={cn('animate-spin', iconSize.xs)} />
   }
 
   const bars = [0.55, 0.85, 1, 0.85, 0.55]
@@ -262,15 +262,7 @@ function ConversationIndicator({
 // Pure-TTS toggle: type normally, but have every assistant reply read aloud —
 // no dictation, no full conversation loop. Filled/accent when on, mirroring the
 // muted-mic pressed state above. Driven by (and persisted to) `voice.auto_tts`.
-function AutoSpeakButton({
-  active,
-  disabled,
-  onToggle
-}: {
-  active: boolean
-  disabled: boolean
-  onToggle: () => void
-}) {
+function AutoSpeakButton({ active, disabled, onToggle }: { active: boolean; disabled: boolean; onToggle: () => void }) {
   const { t } = useI18n()
   const c = t.composer
   const label = active ? c.stopSpeakingReplies : c.speakReplies
@@ -294,7 +286,7 @@ function AutoSpeakButton({
         type="button"
         variant="ghost"
       >
-        {active ? <Volume2 size={14} /> : <VolumeX size={14} />}
+        {active ? <Volume2 className={iconSize.sm} /> : <VolumeX className={iconSize.sm} />}
       </Button>
     </Tip>
   )
@@ -341,9 +333,9 @@ function DictationButton({
         variant="ghost"
       >
         {status === 'recording' ? (
-          <Square className="fill-current" size={11} />
+          <Square className={cn('fill-current', iconSize.xs)} />
         ) : status === 'transcribing' ? (
-          <Loader2 className="animate-spin" size={14} />
+          <Loader2 className={cn('animate-spin', iconSize.sm)} />
         ) : (
           <Codicon name="mic" size="0.875rem" />
         )}
diff --git a/apps/desktop/src/app/chat/composer/queue-panel.tsx b/apps/desktop/src/app/chat/composer/queue-panel.tsx
index fb4365506c0..8c9bc084f59 100644
--- a/apps/desktop/src/app/chat/composer/queue-panel.tsx
+++ b/apps/desktop/src/app/chat/composer/queue-panel.tsx
@@ -3,7 +3,7 @@ import { StatusSection } from '@/components/chat/status-section'
 import { Button } from '@/components/ui/button'
 import { Tip } from '@/components/ui/tooltip'
 import { type Translations, useI18n } from '@/i18n'
-import { ArrowUp, Pencil, Trash2 } from '@/lib/icons'
+import { ArrowUp, iconSize, Pencil, Trash2 } from '@/lib/icons'
 import { cn } from '@/lib/utils'
 import type { QueuedPromptEntry } from '@/store/composer-queue'
 
@@ -52,7 +52,7 @@ export function QueuePanel({ busy, editingId, entries, onDelete, onEdit, onSendN
                     type="button"
                     variant="ghost"
                   >
-                    <Pencil size={11} />
+                    <Pencil className={iconSize.xs} />
                   </Button>
                 </Tip>
                 <Tip label={busy ? c.queueSendNext : c.queueSend}>
@@ -65,7 +65,7 @@ export function QueuePanel({ busy, editingId, entries, onDelete, onEdit, onSendN
                     type="button"
                     variant="ghost"
                   >
-                    <ArrowUp size={11} />
+                    <ArrowUp className={iconSize.xs} />
                   </Button>
                 </Tip>
                 <Tip label={c.queueDelete}>
@@ -77,7 +77,7 @@ export function QueuePanel({ busy, editingId, entries, onDelete, onEdit, onSendN
                     type="button"
                     variant="ghost"
                   >
-                    <Trash2 size={11} />
+                    <Trash2 className={iconSize.xs} />
                   </Button>
                 </Tip>
               </>
diff --git a/apps/desktop/src/app/chat/composer/voice-activity.tsx b/apps/desktop/src/app/chat/composer/voice-activity.tsx
index 535d1422e45..bd1f3303621 100644
--- a/apps/desktop/src/app/chat/composer/voice-activity.tsx
+++ b/apps/desktop/src/app/chat/composer/voice-activity.tsx
@@ -3,7 +3,7 @@ import { useEffect, useRef } from 'react'
 
 import { Button } from '@/components/ui/button'
 import { useI18n } from '@/i18n'
-import { Loader2, Mic, Volume2, VolumeX } from '@/lib/icons'
+import { iconSize, Loader2, Mic, Volume2, VolumeX } from '@/lib/icons'
 import { cn } from '@/lib/utils'
 import { stopVoicePlayback } from '@/lib/voice-playback'
 import { $voicePlayback } from '@/store/voice-playback'
@@ -188,7 +188,7 @@ export function VoiceActivity({ state }: { state: VoiceActivityState }) {
           recording ? 'bg-primary/15 text-primary' : 'bg-primary/10 text-primary'
         )}
       >
-        {recording ? <Mic size={12} /> : <Loader2 className="animate-spin" size={12} />}
+        {recording ? <Mic className={iconSize.xs} /> : <Loader2 className={cn('animate-spin', iconSize.xs)} />}
       </div>
 
       <div className="flex min-w-0 flex-1 items-center gap-2">
@@ -229,7 +229,7 @@ export function VoicePlaybackActivity() {
       role="status"
     >
       <div className="flex size-5 shrink-0 items-center justify-center rounded-full bg-primary/15 text-primary">
-        {preparing ? <Loader2 className="animate-spin" size={12} /> : <Volume2 size={12} />}
+        {preparing ? <Loader2 className={cn('animate-spin', iconSize.xs)} /> : <Volume2 className={iconSize.xs} />}
       </div>
 
       <div className="flex min-w-0 flex-1 items-center gap-2">
@@ -244,7 +244,7 @@ export function VoicePlaybackActivity() {
         type="button"
         variant="ghost"
       >
-        <VolumeX size={12} />
+        <VolumeX className={iconSize.xs} />
         Stop
       </Button>
     </div>
diff --git a/apps/desktop/src/components/desktop-install-overlay.tsx b/apps/desktop/src/components/desktop-install-overlay.tsx
index 0aa75668b2d..e11ae6de0e3 100644
--- a/apps/desktop/src/components/desktop-install-overlay.tsx
+++ b/apps/desktop/src/components/desktop-install-overlay.tsx
@@ -11,7 +11,7 @@ import type {
   DesktopBootstrapState
 } from '@/global'
 import { useI18n } from '@/i18n'
-import { AlertTriangle, Check, ChevronDown, ChevronRight, Loader2 } from '@/lib/icons'
+import { AlertTriangle, Check, ChevronDown, ChevronRight, iconSize, Loader2 } from '@/lib/icons'
 import { cn } from '@/lib/utils'
 
 /**
@@ -109,16 +109,16 @@ function StageRow({ descriptor, result, isCurrent, now }: StageRowProps) {
   const icon = useMemo(() => {
     switch (state) {
       case 'running':
-        return <Loader2 className="h-4 w-4 animate-spin text-primary" />
+        return <Loader2 className={cn(iconSize.md, 'animate-spin text-primary')} />
 
       case 'succeeded':
-        return <Check className="h-4 w-4 text-emerald-600" />
+        return <Check className={cn(iconSize.md, 'text-emerald-600')} />
 
       case 'skipped':
-        return <Check className="h-4 w-4 text-muted-foreground" />
+        return <Check className={cn(iconSize.md, 'text-muted-foreground')} />
 
       case 'failed':
-        return <AlertTriangle className="h-4 w-4 text-destructive" />
+        return <AlertTriangle className={cn(iconSize.md, 'text-destructive')} />
 
       case 'pending':
 
@@ -455,7 +455,7 @@ export function DesktopInstallOverlay({ enabled = true }: DesktopInstallOverlayP
           {failed && state.error && (
             <div className="mb-4 rounded-md border border-destructive/30 bg-destructive/10 p-3 text-sm">
               <div className="mb-1 flex items-center gap-1.5 font-medium text-destructive">
-                <AlertTriangle className="h-4 w-4" />
+                <AlertTriangle className={iconSize.md} />
                 <span>{copy.error}</span>
               </div>
               <p className="whitespace-pre-wrap break-words text-foreground/90">{state.error}</p>
@@ -484,7 +484,7 @@ export function DesktopInstallOverlay({ enabled = true }: DesktopInstallOverlayP
               type="button"
               variant="ghost"
             >
-              {logOpen ? <ChevronDown className="h-3.5 w-3.5" /> : <ChevronRight className="h-3.5 w-3.5" />}
+              {logOpen ? <ChevronDown className={iconSize.sm} /> : <ChevronRight className={iconSize.sm} />}
               <span>{logOpen ? copy.hideOutput : copy.showOutput}</span>
               <span className="ml-1 tabular-nums">({copy.lines(state.log.length)})</span>
             </Button>
@@ -527,7 +527,7 @@ export function DesktopInstallOverlay({ enabled = true }: DesktopInstallOverlayP
                 size="sm"
                 variant="ghost"
               >
-                {cancelling ? <Loader2 className="h-4 w-4 animate-spin" /> : null}
+                {cancelling ? <Loader2 className={cn(iconSize.md, 'animate-spin')} /> : null}
                 {cancelling ? copy.cancelling : copy.cancelInstall}
               </Button>
             </div>
diff --git a/apps/desktop/src/lib/icons.ts b/apps/desktop/src/lib/icons.ts
index f7a825fda15..38e6da317ff 100644
--- a/apps/desktop/src/lib/icons.ts
+++ b/apps/desktop/src/lib/icons.ts
@@ -225,3 +225,19 @@ export {
 }
 
 export type { Icon as IconComponent } from '@tabler/icons-react'
+
+/**
+ * Named icon-size scale — the single source of truth for SVG icon dimensions,
+ * replacing ad-hoc `h-N w-N` / `size={N}`. Use `<Icon className={iconSize.sm} />`
+ * (Tailwind `size-*` sets w+h and beats the icon's default 24px); compose with
+ * `cn()` for colour/animation classes.
+ */
+export const iconSize = {
+  xs: 'size-3', // 12px
+  sm: 'size-3.5', // 14px
+  md: 'size-4', // 16px
+  lg: 'size-5', // 20px
+  xl: 'size-6' // 24px
+} as const
+
+export type IconSize = keyof typeof iconSize