diff --git a/packages/editor/src/components/tools/item/placement-math.ts b/packages/editor/src/components/tools/item/placement-math.ts
index 2895de32..3f6295fa 100644
--- a/packages/editor/src/components/tools/item/placement-math.ts
+++ b/packages/editor/src/components/tools/item/placement-math.ts
@@ -1,22 +1,30 @@
 import { isObject } from '@pascal-app/core'
+import useEditor from '../../../store/use-editor'
+
+function getGridSnapStep(): number {
+  return useEditor.getState().gridSnapStep
+}
+
+function positiveModulo(value: number, divisor: number): number {
+  return ((value % divisor) + divisor) % divisor
+}
 
 /**
  * Snaps a position to 0.5 grid, with an offset to align item edges to grid lines.
  * For items with dimensions like 2.5, the center would be at 1.25 from the edge,
  * which doesn't align with 0.5 grid. This adds an offset so edges align instead.
  */
-export function snapToGrid(position: number, dimension: number): number {
+export function snapToGrid(position: number, dimension: number, step = getGridSnapStep()): number {
   const halfDim = dimension / 2
-  const needsOffset = Math.abs(((halfDim * 2) % 1) - 0.5) < 0.01
-  const offset = needsOffset ? 0.25 : 0
-  return Math.round((position - offset) * 2) / 2 + offset
+  const offset = positiveModulo(halfDim, step)
+  return Math.round((position - offset) / step) * step + offset
 }
 
 /**
  * Snap a value to 0.5 increments (used for wall-local positions).
  */
-export function snapToHalf(value: number): number {
-  return Math.round(value * 2) / 2
+export function snapToHalf(value: number, step = getGridSnapStep()): number {
+  return Math.round(value / step) * step
 }
 
 /**
diff --git a/packages/editor/src/components/tools/wall/wall-drafting.ts b/packages/editor/src/components/tools/wall/wall-drafting.ts
index 91ba5180..ab017197 100755
--- a/packages/editor/src/components/tools/wall/wall-drafting.ts
+++ b/packages/editor/src/components/tools/wall/wall-drafting.ts
@@ -11,6 +11,7 @@ import {
 } from '@pascal-app/core'
 import { useViewer } from '@pascal-app/viewer'
 import { sfxEmitter } from '../../../lib/sfx-bus'
+import useEditor from '../../../store/use-editor'
 
 export type WallPlanPoint = [number, number]
 
@@ -29,6 +30,10 @@ function distanceSquared(a: WallPlanPoint, b: WallPlanPoint): number {
   return dx * dx + dz * dz
 }
 
+function getWallGridStep(): number {
+  return useEditor.getState().gridSnapStep
+}
+
 function snapScalarToGrid(value: number, step = WALL_GRID_STEP): number {
   return Math.round(value / step) * step
 }
@@ -37,7 +42,11 @@ export function snapPointToGrid(point: WallPlanPoint, step = WALL_GRID_STEP): Wa
   return [snapScalarToGrid(point[0], step), snapScalarToGrid(point[1], step)]
 }
 
-export function snapPointTo45Degrees(start: WallPlanPoint, cursor: WallPlanPoint): WallPlanPoint {
+export function snapPointTo45Degrees(
+  start: WallPlanPoint,
+  cursor: WallPlanPoint,
+  step = WALL_GRID_STEP,
+): WallPlanPoint {
   const dx = cursor[0] - start[0]
   const dz = cursor[1] - start[1]
   const angle = Math.atan2(dz, dx)
@@ -47,7 +56,7 @@ export function snapPointTo45Degrees(start: WallPlanPoint, cursor: WallPlanPoint
   return snapPointToGrid([
     start[0] + Math.cos(snappedAngle) * distance,
     start[1] + Math.sin(snappedAngle) * distance,
-  ])
+  ], step)
 }
 
 function projectPointOntoWall(point: WallPlanPoint, wall: WallNode): WallPlanPoint | null {
@@ -348,7 +357,9 @@ export function snapWallDraftPoint(args: {
   ignoreWallIds?: string[]
 }): WallPlanPoint {
   const { point, walls, start, angleSnap = false, ignoreWallIds } = args
-  const basePoint = start && angleSnap ? snapPointTo45Degrees(start, point) : snapPointToGrid(point)
+  const step = getWallGridStep()
+  const basePoint =
+    start && angleSnap ? snapPointTo45Degrees(start, point, step) : snapPointToGrid(point, step)
 
   return (
     findWallSnapTarget(basePoint, walls, {
diff --git a/packages/editor/src/components/ui/viewer-toolbar.tsx b/packages/editor/src/components/ui/viewer-toolbar.tsx
index bf4c460c..b81a5c71 100644
--- a/packages/editor/src/components/ui/viewer-toolbar.tsx
+++ b/packages/editor/src/components/ui/viewer-toolbar.tsx
@@ -6,7 +6,7 @@ import { ChevronsLeft, ChevronsRight, Columns2, Eye, Footprints, Moon, Sun } fro
 import { useCallback } from 'react'
 import { cn } from '../../lib/utils'
 import useEditor from '../../store/use-editor'
-import type { ViewMode } from '../../store/use-editor'
+import type { GridSnapStep, ViewMode } from '../../store/use-editor'
 import { useSidebarStore } from './primitives/sidebar'
 import { Tooltip, TooltipContent, TooltipTrigger } from './primitives/tooltip'
 
@@ -174,6 +174,18 @@ const levelModeLabels: Record<string, string> = {
   solo: 'Solo',
 }
 
+const gridSnapOrder: GridSnapStep[] = [0.5, 0.25, 0.1, 0.05]
+const gridSnapLabels: Record<GridSnapStep, string> = {
+  0.5: '0.5',
+  0.25: '0.25',
+  0.1: '0.10',
+  0.05: '0.05',
+}
+
+function formatGridSnapStep(step: GridSnapStep): string {
+  return gridSnapLabels[step]
+}
+
 function LevelModeToggle() {
   const levelMode = useViewer((s) => s.levelMode)
   const setLevelMode = useViewer((s) => s.setLevelMode)
@@ -219,6 +231,29 @@ function LevelModeToggle() {
   )
 }
 
+function GridSnapToggle() {
+  const gridSnapStep = useEditor((s) => s.gridSnapStep)
+  const setGridSnapStep = useEditor((s) => s.setGridSnapStep)
+
+  const cycle = () => {
+    const idx = gridSnapOrder.indexOf(gridSnapStep)
+    const next = gridSnapOrder[(idx + 1) % gridSnapOrder.length]
+    if (next) setGridSnapStep(next)
+  }
+
+  return (
+    <Tooltip>
+      <TooltipTrigger asChild>
+        <button className={cn(TOOLBAR_BTN, 'w-auto gap-1.5 px-2.5')} onClick={cycle} type="button">
+          <IconifyIcon height={14} icon="lucide:grid-2x2" width={14} />
+          <span className="font-medium text-xs">{formatGridSnapStep(gridSnapStep)}</span>
+        </button>
+      </TooltipTrigger>
+      <TooltipContent side="bottom">Grid snap: {formatGridSnapStep(gridSnapStep)}</TooltipContent>
+    </Tooltip>
+  )
+}
+
 // ── Wall mode toggle ────────────────────────────────────────────────────────
 
 const wallModeOrder = ['cutaway', 'up', 'down'] as const
@@ -329,6 +364,7 @@ export function ViewerToolbarRight() {
   return (
     <div className={TOOLBAR_CONTAINER}>
       <LevelModeToggle />
+      <GridSnapToggle />
       <WallModeToggle />
       <div className="my-1.5 w-px bg-border/50" />
       <UnitToggle />
diff --git a/packages/editor/src/store/use-editor.tsx b/packages/editor/src/store/use-editor.tsx
index c648451e..6fa9bb4b 100644
--- a/packages/editor/src/store/use-editor.tsx
+++ b/packages/editor/src/store/use-editor.tsx
@@ -70,6 +70,7 @@ export type CatalogCategory =
 export type StructureLayer = 'zones' | 'elements'
 
 export type FloorplanSelectionTool = 'click' | 'marquee'
+export type GridSnapStep = 0.5 | 0.25 | 0.1 | 0.05
 
 // Combined tool type
 export type Tool = SiteTool | StructureTool | FurnishTool
@@ -150,6 +151,8 @@ type EditorState = {
   setFloorplanHovered: (hovered: boolean) => void
   floorplanSelectionTool: FloorplanSelectionTool
   setFloorplanSelectionTool: (tool: FloorplanSelectionTool) => void
+  gridSnapStep: GridSnapStep
+  setGridSnapStep: (step: GridSnapStep) => void
   // First-person walkthrough mode (street view)
   isFirstPersonMode: boolean
   _viewModeBeforeFirstPerson: ViewMode | null
@@ -170,7 +173,11 @@ export type PersistedEditorUiState = Pick<
 
 type PersistedEditorLayoutState = Pick<
   EditorState,
-  'activeSidebarPanel' | 'floorplanPaneRatio' | 'splitOrientation' | 'floorplanSelectionTool'
+  | 'activeSidebarPanel'
+  | 'floorplanPaneRatio'
+  | 'splitOrientation'
+  | 'floorplanSelectionTool'
+  | 'gridSnapStep'
 >
 type PersistedEditorState = PersistedEditorUiState & PersistedEditorLayoutState
 
@@ -189,8 +196,11 @@ export const DEFAULT_PERSISTED_EDITOR_LAYOUT_STATE: PersistedEditorLayoutState =
   floorplanPaneRatio: DEFAULT_FLOORPLAN_PANE_RATIO,
   splitOrientation: 'horizontal',
   floorplanSelectionTool: 'click',
+  gridSnapStep: 0.5,
 }
 
+const GRID_SNAP_STEPS: GridSnapStep[] = [0.5, 0.25, 0.1, 0.05]
+
 function normalizeModeForPhase(phase: Phase, mode: Mode | undefined): Mode {
   if (phase === 'site') {
     return 'select'
@@ -293,6 +303,9 @@ function normalizePersistedEditorLayoutState(
     floorplanPaneRatio: normalizeFloorplanPaneRatio(state?.floorplanPaneRatio),
     splitOrientation: state?.splitOrientation === 'vertical' ? 'vertical' : 'horizontal',
     floorplanSelectionTool: state?.floorplanSelectionTool === 'marquee' ? 'marquee' : 'click',
+    gridSnapStep: GRID_SNAP_STEPS.includes(state?.gridSnapStep as GridSnapStep)
+      ? (state?.gridSnapStep as GridSnapStep)
+      : DEFAULT_PERSISTED_EDITOR_LAYOUT_STATE.gridSnapStep,
   }
 }
 
@@ -520,6 +533,8 @@ const useEditor = create<EditorState>()(
       setFloorplanHovered: (hovered) => set({ isFloorplanHovered: hovered }),
       floorplanSelectionTool: 'click' as FloorplanSelectionTool,
       setFloorplanSelectionTool: (tool) => set({ floorplanSelectionTool: tool }),
+      gridSnapStep: DEFAULT_PERSISTED_EDITOR_LAYOUT_STATE.gridSnapStep,
+      setGridSnapStep: (step) => set({ gridSnapStep: step }),
       allowUndergroundCamera: false,
       setAllowUndergroundCamera: (enabled) => set({ allowUndergroundCamera: enabled }),
       isFirstPersonMode: false,
@@ -585,6 +600,7 @@ const useEditor = create<EditorState>()(
         floorplanPaneRatio: state.floorplanPaneRatio,
         splitOrientation: state.splitOrientation,
         floorplanSelectionTool: state.floorplanSelectionTool,
+        gridSnapStep: state.gridSnapStep,
       }),
     },
   ),