diff --git a/B04_PreProcess/B04_PreProcess_Engine_Smooth.py b/B04_PreProcess/B04_PreProcess_Engine_Smooth.py
index d06858f3f..03e5b60fa 100644
--- a/B04_PreProcess/B04_PreProcess_Engine_Smooth.py
+++ b/B04_PreProcess/B04_PreProcess_Engine_Smooth.py
@@ -90,7 +90,7 @@ def smooth_dtm(
         y=y_coords,
         z=z_smooth,
         valid_mask=valid_grid,
-        resolution=np.array([preview_res], np.float32),
+        resolution=np.array([x_coords[1] - x_coords[0]], np.float32),  # 넓힌 실제 칸(633)
     )
     write_glb(preview_path, vertices_compact, faces_compact, context.bounds)
     return {
diff --git a/B07_DesignDetail/B07_DesignDetail_Router_Support_Basin.py b/B07_DesignDetail/B07_DesignDetail_Router_Support_Basin.py
index 82f38e41f..9062e89d2 100644
--- a/B07_DesignDetail/B07_DesignDetail_Router_Support_Basin.py
+++ b/B07_DesignDetail/B07_DesignDetail_Router_Support_Basin.py
@@ -25,6 +25,7 @@ from B07_DesignDetail.B07_DesignDetail_Engine_Cad_Plan import (
     plan_drawing_label,
 )
 from common_util.common_util_drainage_pipes import detail_basins_path
+from common_util.common_util_grid_cell import grid_cell_m
 from config.config_system import (
     BASIN_CONTOUR_INTERVAL_M,
     DRAWING_SCALE_BASIN,
@@ -490,7 +491,7 @@ def _hillshade_for_box(
         grid_y = np.asarray(data["y"], dtype=np.float64)
         grid_z = np.asarray(data["z"], dtype=np.float64)
         valid = np.asarray(data["valid_mask"], dtype=bool)
-        resolution = float(np.asarray(data["resolution"]).reshape(-1)[0])
+        resolution = grid_cell_m(data, grid_x)
 
     min_x, min_y, max_x, max_y = box
     columns = np.where((grid_x >= min_x) & (grid_x <= max_x))[0]
diff --git a/D03_PlanAnalysis/D03_PlanAnalysis_Layers.py b/D03_PlanAnalysis/D03_PlanAnalysis_Layers.py
index a0d249f54..f1f027bb1 100644
--- a/D03_PlanAnalysis/D03_PlanAnalysis_Layers.py
+++ b/D03_PlanAnalysis/D03_PlanAnalysis_Layers.py
@@ -47,6 +47,7 @@ from common_util.common_util_derived_store import (
     read_derived,
     write_derived,
 )
+from common_util.common_util_grid_cell import grid_cell_m
 from common_util.common_util_json import atomic_write_json
 from config.config_system_terrain import SHEET_SURFACE_DEFAULT_METHOD
 
@@ -64,9 +65,9 @@ WFS_WORKERS = 4
 
 SLOPE_KIND = "plan_slope"
 HILLSHADE_KIND = "plan_hillshade"
-HILLSHADE_VERSION = 2  # 빈 칸 투명
+HILLSHADE_VERSION = 3  # 칸 = 좌표 간격(633)
 RASTER_KINDS = ("slope", "hillshade")
-SLOPE_VERSION = 2  # 값 그림 + 1 % 칸 수(PLAN 603)
+SLOPE_VERSION = 3  # 칸 = 좌표 간격(633)
 SLOPE_MAX_PCT = 250  # 칸 값 0~250 = 기울기 % 내림(250 = 250 % 이상)
 SLOPE_EMPTY = 255  # 빈 칸
 MAX_SIDE_PX = 4096  # ponytail: 한 변 넘으면 솎음 · 넓은 사업은 조각 그림으로
@@ -273,7 +274,7 @@ def slope_layer(
         return saved["value"]
     with np.load(npz) as dem:
         x, y = np.asarray(dem["x"], float), np.asarray(dem["y"], float)
-        cell = float(dem["resolution"][0]) if "resolution" in dem.files else float(x[1] - x[0])
+        cell = grid_cell_m(dem, x)
         value = build(dem["z"], np.asarray(dem["valid_mask"], bool), cell)
     half = cell / 2
     box = (x[0] - half, y[0] - half, x[-1] + half, y[-1] + half)
diff --git a/D03_PlanAnalysis/D03_PlanAnalysis_ZeroOrder.py b/D03_PlanAnalysis/D03_PlanAnalysis_ZeroOrder.py
index 885b91935..7a3b75c95 100644
--- a/D03_PlanAnalysis/D03_PlanAnalysis_ZeroOrder.py
+++ b/D03_PlanAnalysis/D03_PlanAnalysis_ZeroOrder.py
@@ -41,6 +41,7 @@ from common_util.common_util_derived_store import (
     read_derived,
     write_derived,
 )
+from common_util.common_util_grid_cell import grid_cell_m
 from common_util.common_util_json import atomic_write_json
 from config.config_system_terrain import SHEET_SURFACE_DEFAULT_METHOD
 
@@ -420,7 +421,7 @@ def _project_box(npz: Path) -> tuple[float, float, float, float]:
     """사업 DEM 범위(칸 모서리) — 창고 격자에서 이 상자 안 칸을 씀."""
     with np.load(npz) as dem:
         x, y = np.asarray(dem["x"], float), np.asarray(dem["y"], float)
-        cell = float(dem["resolution"][0]) if "resolution" in dem.files else float(x[1] - x[0])
+        cell = grid_cell_m(dem, x)
     half = cell / 2
     return (x[0] - half, y[0] - half, x[-1] + half, y[-1] + half)
 
@@ -500,6 +501,7 @@ def zero_order_layer(
 
 
 DEM_ZERO_ORDER_KIND = "plan_zero_order_dem"
+DEM_ZERO_ORDER_VERSION = 4  # 칸 = 좌표 간격(633) · 도엽 길 판과 따로
 
 
 def dem_zero_order_layer(
@@ -519,7 +521,7 @@ def dem_zero_order_layer(
         raise FileNotFoundError("지형 격자가 없습니다.")
     key = derived_key(
         DEM_ZERO_ORDER_KIND,
-        ZERO_ORDER_VERSION,
+        DEM_ZERO_ORDER_VERSION,
         npz.name,
         stamp,
         int(epsg),
@@ -534,7 +536,7 @@ def dem_zero_order_layer(
         return saved["value"] if saved is not None else None
     with np.load(npz) as dem:
         x, y = np.asarray(dem["x"], float), np.asarray(dem["y"], float)
-        cell = float(dem["resolution"][0]) if "resolution" in dem.files else float(x[1] - x[0])
+        cell = grid_cell_m(dem, x)
         step = max(1, round(ZERO_ORDER_CELL_M / cell))
         z = np.asarray(dem["z"], float)[::step, ::step]
         valid = np.asarray(dem["valid_mask"], bool)[::step, ::step]
diff --git a/common_util/common_util_grid_cell.py b/common_util/common_util_grid_cell.py
new file mode 100644
index 000000000..6172c61ef
--- /dev/null
+++ b/common_util/common_util_grid_cell.py
@@ -0,0 +1,27 @@
+"""격자 칸 크기(m) — 적힌 칸(`resolution`)보다 좌표 간격을 믿음(633).
+
+B04 평활 격자는 꼭짓점이 많으면 칸을 넓히고 적힌 칸은 요청값 그대로라 둘이 어긋남.
+둘이 맞으면(1 % 안) 적힌 값을 그대로 돌려줘 옛 결과와 같음.
+"""
+
+from __future__ import annotations
+
+import logging
+import math
+from typing import Any
+
+import numpy as np
+
+logger = logging.getLogger(__name__)
+
+
+def grid_cell_m(dem: Any, x: Any) -> float:
+    """npz 격자(`dem`)의 칸 — `x` = 열 좌표."""
+    spacing = abs(float(x[1] - x[0]))
+    if "resolution" not in dem.files:
+        return spacing
+    written = float(np.asarray(dem["resolution"]).reshape(-1)[0])
+    if math.isclose(written, spacing, rel_tol=0.01):
+        return written
+    logger.warning("격자 칸 %.3f m 로 적힘 · 좌표 간격 %.3f m — 좌표 간격을 씀", written, spacing)
+    return spacing
diff --git a/resources/tester/test_633_grid_cell.py b/resources/tester/test_633_grid_cell.py
new file mode 100644
index 000000000..74ca22587
--- /dev/null
+++ b/resources/tester/test_633_grid_cell.py
@@ -0,0 +1,110 @@
+"""격자 칸 = 좌표 간격(요구 538 · PLAN 633).
+
+- 적힌 칸(0.5) ≠ 좌표 간격(1.0) → 급경사 · 음영 · 0차곡이 좌표 간격으로 셈
+- 둘이 맞는 격자(D 수치지형도) → 적힌 값 그대로 · 결과 전과 같음
+
+./venv/Scripts/python.exe -m pytest resources/tester/test_633_grid_cell.py -q
+"""
+
+import logging
+
+import numpy as np
+
+from common_util.common_util_grid_cell import grid_cell_m
+from D03_PlanAnalysis import D03_PlanAnalysis_Layers as layers
+from D03_PlanAnalysis import D03_PlanAnalysis_ZeroOrder as zero_order
+
+EPSG = 5186
+X0, Y0 = 200000.0, 450000.0
+
+
+def _npz(path, cell: float, written: float | None, n: int = 60, tilt: float = 0.5):
+    x, y = X0 + np.arange(n) * cell, Y0 + np.arange(n) * cell
+    z = np.add.outer(np.zeros(n), x - X0) * tilt  # 동쪽으로 tilt(= 50 %)
+    extra = {} if written is None else {"resolution": np.array([written], np.float32)}
+    path.parent.mkdir(parents=True, exist_ok=True)
+    np.savez(path, x=x, y=y, z=z, valid_mask=np.ones(z.shape, bool), **extra)
+    return path
+
+
+def test_grid_cell_prefers_spacing(tmp_path, caplog) -> None:
+    with np.load(_npz(tmp_path / "a.npz", 2.0, 2.0)) as dem:
+        assert grid_cell_m(dem, dem["x"]) == 2.0
+    with np.load(_npz(tmp_path / "b.npz", 1.5, None)) as dem:
+        assert grid_cell_m(dem, dem["x"]) == 1.5
+    with caplog.at_level(logging.WARNING), np.load(_npz(tmp_path / "c.npz", 1.078, 0.5)) as dem:
+        assert abs(grid_cell_m(dem, dem["x"]) - 1.078) < 1e-9
+    assert "좌표 간격" in caplog.text
+
+
+def test_slope_uses_real_cell(tmp_path) -> None:
+    npz = _npz(tmp_path / "models" / "dtm_csf_smooth.npz", 1.0, 0.5)
+    value = layers.slope_layer(tmp_path, tmp_path / "models", EPSG, npz=npz)
+    counts = np.asarray(value["counts"])
+    assert int(counts.argmax()) == 50  # 0.5 를 믿으면 100
+    assert value["box_m"][0] == X0 - 0.5
+
+
+def test_sheet_slope_unchanged(tmp_path) -> None:
+    """적힌 칸 = 좌표 간격 → 옛 셈(적힌 칸)과 같은 그림."""
+    npz = _npz(tmp_path / "models" / "dtm_sheet_x.npz", 2.0, 2.0)
+    value = layers.slope_layer(tmp_path, tmp_path / "models", EPSG, npz=npz)
+    with np.load(npz) as dem:
+        old = layers.slope_values_png(dem["z"], dem["valid_mask"], 2.0)
+    assert value["image"] == old["image"] and value["counts"] == old["counts"]
+
+
+def test_hillshade_uses_real_cell(tmp_path) -> None:
+    npz = _npz(tmp_path / "models" / "dtm_csf_smooth.npz", 1.0, 0.5)
+    value = layers.slope_layer(tmp_path, tmp_path / "models", EPSG, kind="hillshade", npz=npz)
+    with np.load(npz) as dem:
+        real = layers.hillshade_layer_png(dem["z"], dem["valid_mask"], 1.0)
+    assert value["image"] == real["image"]
+
+
+def test_zero_order_dem_uses_real_cell(tmp_path, monkeypatch) -> None:
+    npz = _npz(tmp_path / "models" / "dtm_csf_smooth.npz", 1.0, 0.5, n=40)
+    seen = {}
+
+    def spy(z, valid, x, y, cell, *rest):
+        seen.update(shape=z.shape, dx=float(x[1] - x[0]), cell=cell)
+        return []
+
+    monkeypatch.setattr(zero_order, "zero_order_lines", spy)
+    value = zero_order.dem_zero_order_layer(tmp_path, npz, EPSG)
+    # 0.5 를 믿으면 4 칸 건너(10×10 · 실제 4 m 를 2 m 로 셈)
+    assert seen == {"shape": (20, 20), "dx": 2.0, "cell": 2.0} and value["cell_m"] == 2.0
+    assert zero_order._project_box(npz)[0] == X0 - 0.5
+
+
+def test_b07_frame_hillshade_uses_real_cell(tmp_path) -> None:
+    """B07 도곽 음영 — 옛 평활 파일(0.5 적힘)도 좌표 간격으로."""
+    from types import SimpleNamespace
+
+    from B07_DesignDetail.B07_DesignDetail_Engine_Cad_Lidar import hillshade_png
+    from B07_DesignDetail.B07_DesignDetail_Router_Support_Basin import _hillshade_for_box
+
+    npz = _npz(tmp_path / "B04_PreProcess" / "models" / "dtm_csf_smooth.npz", 1.0, 0.5)
+    context = SimpleNamespace(project_root=tmp_path, surface_params={})
+    url, _ = _hillshade_for_box(context, (X0, Y0, X0 + 100, Y0 + 100))
+    with np.load(npz) as dem:
+        assert url == hillshade_png(dem["z"], dem["valid_mask"], 1.0)[0]
+
+
+def test_smooth_writes_real_cell(tmp_path) -> None:
+    """B04 평활 격자 — 칸을 넓히면(꼭짓점 상한) 넓힌 칸을 적음."""
+    from types import SimpleNamespace
+
+    from B04_PreProcess.B04_PreProcess_Engine_Smooth import smooth_dtm
+
+    src = _npz(tmp_path / "dtm_csf.npz", 1.0, 1.0, n=20)
+    wide = X0 + np.arange(10) * 2.0  # 요청 0.5 → 상한 때문에 2.0
+    context = SimpleNamespace(
+        config={"dtm_grid_resolution_meters": 1.0},
+        preview_grid=lambda res: (wide, Y0 + np.arange(10) * 2.0, None),
+        contains_xy=lambda xs, ys: np.ones(np.shape(xs), bool),
+        bounds=np.array([[X0, X0 + 18.0], [Y0, Y0 + 18.0], [0.0, 10.0]]),
+    )
+    smooth_dtm(context, tmp_path, "dtm_csf", src)
+    with np.load(tmp_path / "dtm_csf_smooth.npz") as dem:
+        assert float(dem["resolution"][0]) == 2.0