diff --git a/B07_DesignDetail/B07_DesignDetail_UI_Settings.ts b/B07_DesignDetail/B07_DesignDetail_UI_Settings.ts
index e4012364c..d8cdcb0c2 100644
--- a/B07_DesignDetail/B07_DesignDetail_UI_Settings.ts
+++ b/B07_DesignDetail/B07_DesignDetail_UI_Settings.ts
@@ -4,7 +4,7 @@
  *
  *   평면도 = 평면도 관리 모달 그대로(`openPlanManager`)
  *   횡단도 = 장 배치(열 · 행 · [이 장] · [모든 장]) · 표 배율 · [안내선 숨기기] — 좌측 카드 밑에서 옮김
- *   구조물 도면 = 「M02 그림 — 축척 없음」 한 줄 · 종단 · 토적 · 전개도 = 몸 비움(축척 칸은 485-2)
+ *   구조물 도면 = 「M02 그림 — 축척 없음」 한 줄 · 종단 · 횡단 · 토적 · 전개도 = X · Y 축척 칸(`_UI_Settings_Scale`)
  *   [원본에서 다시 그리기] = 지금 연 도면이 그 묶음일 때만 켬
  * ========================================================================== */
 
@@ -17,6 +17,7 @@ import {
   isCrossSheet,
 } from "./B07_DesignDetail_UI_Panels";
 import { openPlanManager, type PlanManageControls } from "./B07_DesignDetail_UI_PlanManage";
+import { mountDrawingScale } from "./B07_DesignDetail_UI_Settings_Scale";
 
 type Kind = DesignDrawingItem["kind"];
 
@@ -81,6 +82,7 @@ export function openDrawingSettings(kind: Kind, deps: DrawingSettingsDeps): void
       closeModal = close;
       if (mine) body.append(note(`지금 도면: ${current?.label}`));
       if (kind === "structure") body.append(note("M02 그림 — 축척 없음"));
+      mountDrawingScale(body, kind, deps, close);
       if (kind === "cross") mountCross(body, deps, close);
     },
   });
diff --git a/B07_DesignDetail/B07_DesignDetail_UI_Settings_Scale.ts b/B07_DesignDetail/B07_DesignDetail_UI_Settings_Scale.ts
new file mode 100644
index 000000000..28352bd08
--- /dev/null
+++ b/B07_DesignDetail/B07_DesignDetail_UI_Settings_Scale.ts
@@ -0,0 +1,157 @@
+/* =============================================================================
+ * B07_DesignDetail_UI_Settings_Scale.ts
+ * ⚙ 모달 X · Y 축척 칸(485-2 · 요구 280-5) — 종단 · 횡단 · 토적 · 전개도만.
+ *
+ *   칸 = 분모 정수 · 범위 밖 = 칸 붉게 + [축척 저장] 꺼짐 · 기본이 자동인 칸(토적 X · 전개도) = 「자동」
+ *   [축척 저장] = 그 종류 저장본이 있으면 n 장 물음(취소 = 그대로) → PUT → 화면 다시 세움(도면 다시 그림)
+ *   [기본값] = 칸만 기본으로 채움 — 저장은 [축척 저장]
+ * ========================================================================== */
+
+import { createCheckbox } from "@ui/ui_template_checkbox";
+import {
+  createButton,
+  createInputField,
+  hideLoadingOverlay,
+  showConfirmDialog,
+  showLoadingOverlay,
+  showToast,
+} from "@ui/ui_template_elements";
+import {
+  type DrawingScaleAxes,
+  type DrawingScaleKind,
+  type DrawingScales,
+  fetchDrawingScales,
+  saveDrawingScales,
+} from "./B07_DesignDetail_Api_Fetch";
+import type { DrawingSettingsDeps } from "./B07_DesignDetail_UI_Settings";
+import { readScaleAxis, scaleToSend } from "./logic/B07_DesignDetail_Scale_Check";
+
+const LABEL: Record<DrawingScaleKind, string> = {
+  longitudinal: "종단도",
+  cross: "횡단도",
+  mass_haul: "토적도",
+  development: "전개도",
+};
+const AXES = [
+  ["x", "X(가로) 1/"],
+  ["y", "Y(세로) 1/"],
+] as const;
+
+const isScaleKind = (kind: string): kind is DrawingScaleKind => kind in LABEL;
+
+/** ⚙ 모달 몸에 축척 칸을 붙임 — 축척 없는 종류는 아무것도 안 함. */
+export function mountDrawingScale(
+  body: HTMLElement,
+  kind: string,
+  deps: DrawingSettingsDeps,
+  close: () => void,
+): void {
+  if (!isScaleKind(kind) || !deps.plan) return;
+  const { projectId, onClosed } = deps.plan;
+  const section = document.createElement("div");
+  section.className = "b07-scale";
+  section.textContent = "축척 받는 중…";
+  body.append(section);
+  void fetchDrawingScales(projectId)
+    .then((data) => {
+      section.textContent = "";
+      buildScaleFields(section, kind, data, async (next) => {
+        const saved = data.saved[kind] ?? 0;
+        const ask = `${LABEL[kind]} 축척을 바꾸면 저장본 ${saved}장이 풀립니다(원본에서 다시 그림). 바꿀까요?`;
+        if (saved > 0 && !(await showConfirmDialog(ask, "바꿈"))) return;
+        showLoadingOverlay();
+        try {
+          await saveDrawingScales(projectId, { [kind]: next });
+          close();
+          showToast(`${LABEL[kind]} 축척을 바꿨습니다.`, "success");
+          onClosed(true, deps.current()?.id); // 목록 · 도면을 서버에서 다시 받아 다시 그림
+        } catch (error) {
+          showToast(
+            error instanceof Error ? error.message : "축척을 저장하지 못했습니다.",
+            "error",
+          );
+        } finally {
+          hideLoadingOverlay();
+        }
+      });
+    })
+    .catch(() => {
+      section.textContent = "축척을 받지 못했습니다.";
+    });
+}
+
+function buildScaleFields(
+  section: HTMLElement,
+  kind: DrawingScaleKind,
+  data: DrawingScales,
+  save: (next: DrawingScaleAxes) => Promise<void>,
+): void {
+  const fields = AXES.map(([axis, label]) => {
+    const fallback = data.defaults[kind][axis];
+    const range = data.ranges[kind][axis];
+    const [min, max] = range;
+    const field = createInputField({ label, type: "number", compact: true, min, max });
+    field.root.classList.add("b07-scale__field");
+    const auto = fallback === null ? createCheckbox("자동") : undefined;
+    if (auto) field.root.append(auto.root);
+    const set = (value: number | null): void => {
+      field.input.value = value === null ? "" : String(value);
+      if (auto) auto.input.checked = value === null;
+      field.input.disabled = value === null && !!auto;
+    };
+    set(data.scales[kind][axis]);
+    const read = () => readScaleAxis(field.input.value, !!auto?.input.checked, range);
+    return { axis, field, auto, fallback, set, read };
+  });
+
+  const saveButton = createButton({
+    label: "축척 저장",
+    onClick: () => {
+      const [x, y] = fields.map((f) => f.read()) as [number | null, number | null];
+      const now = data.scales[kind];
+      if (x === now.x && y === now.y) {
+        showToast("바뀐 축척이 없습니다.", "info");
+        return;
+      }
+      void save({ x: scaleToSend(x, fields[0].fallback), y: scaleToSend(y, fields[1].fallback) });
+    },
+  });
+  const check = (): void => {
+    let bad = false;
+    for (const f of fields) {
+      const result = f.read();
+      f.field.setError(typeof result === "string" ? result : undefined);
+      bad ||= typeof result === "string";
+    }
+    saveButton.disabled = bad;
+  };
+  for (const f of fields) {
+    f.field.input.addEventListener("input", check);
+    f.auto?.input.addEventListener("change", () => {
+      if (f.auto!.input.checked) f.set(null);
+      else f.field.input.disabled = false; // 빈 칸 — 숫자를 적어야 저장
+      check();
+    });
+  }
+  const reset = createButton({
+    label: "기본값",
+    variant: "ghost",
+    onClick: () => {
+      fields.forEach((f) => f.set(f.fallback));
+      check();
+    },
+  });
+  reset.title = "칸을 기본 축척으로 채움 — [축척 저장]으로 씀";
+
+  const title = document.createElement("p");
+  title.className = "b07-settings__note";
+  title.textContent =
+    kind === "cross" ? "축척 — 횡단도 장(표준 횡단면도 뺌)" : `축척 — ${LABEL[kind]}`;
+  const row = document.createElement("div");
+  row.className = "b07-scale__row";
+  row.append(...fields.map((f) => f.field.root));
+  const buttons = document.createElement("div");
+  buttons.className = "b07-scale__actions";
+  buttons.append(reset, saveButton);
+  section.append(title, row, buttons);
+}
diff --git a/B07_DesignDetail/B07_DesignDetail_UI_Style.css b/B07_DesignDetail/B07_DesignDetail_UI_Style.css
index bd92bbb2c..7ac6e74ca 100644
--- a/B07_DesignDetail/B07_DesignDetail_UI_Style.css
+++ b/B07_DesignDetail/B07_DesignDetail_UI_Style.css
@@ -503,3 +503,27 @@ html.is-bm-route .b07-cad-stack > .cad-tabs {
   gap: var(--spacing-8);
   min-width: 280px;
 }
+
+/* ⚙ 축척 칸(485-2) — X · Y 두 칸 한 줄 · 단추 오른쪽 */
+.b07-scale {
+  display: flex;
+  flex-direction: column;
+  gap: var(--spacing-8);
+  min-width: 280px;
+  margin-bottom: var(--spacing-8);
+}
+
+.b07-scale__row {
+  display: flex;
+  gap: var(--spacing-8);
+}
+
+.b07-scale__field {
+  flex: 1;
+}
+
+.b07-scale__actions {
+  display: flex;
+  justify-content: flex-end;
+  gap: var(--spacing-8);
+}
diff --git a/B07_DesignDetail/logic/B07_DesignDetail_Scale_Check.ts b/B07_DesignDetail/logic/B07_DesignDetail_Scale_Check.ts
new file mode 100644
index 000000000..7c3b2c307
--- /dev/null
+++ b/B07_DesignDetail/logic/B07_DesignDetail_Scale_Check.ts
@@ -0,0 +1,24 @@
+/* =============================================================================
+ * B07_DesignDetail_Scale_Check.ts
+ * ⚙ 축척 칸(485-2) 판정 — 칸 글 → 분모(정수 · 범위 안) · 자동 = null · 틀리면 까닭 글.
+ * 서버 `checked_scales`(`_Router_Support_Scale.py`)와 같은 규칙 — 범위는 서버가 내려 줌.
+ * ========================================================================== */
+
+/** 칸 하나 읽기 — 숫자 · null(자동) · 까닭 글(틀림). */
+export function readScaleAxis(
+  raw: string,
+  auto: boolean,
+  [low, high]: [number, number],
+): number | null | string {
+  if (auto) return null;
+  const text = raw.trim().replace(/,/g, "");
+  const value = Number(text);
+  if (text === "" || !Number.isInteger(value) || value < low || value > high) {
+    return `1/${low.toLocaleString()}~1/${high.toLocaleString()} 사이 정수`;
+  }
+  return value;
+}
+
+/** 보낼 값 — 기본값과 같으면 null(파일엔 기본 그대로 남김). */
+export const scaleToSend = (value: number | null, fallback: number | null): number | null =>
+  value === fallback ? null : value;
diff --git a/resources/tester/helper_280_5_b07_settings.cjs b/resources/tester/helper_280_5_b07_settings.cjs
index 179a6018e..be4ebe47d 100644
--- a/resources/tester/helper_280_5_b07_settings.cjs
+++ b/resources/tester/helper_280_5_b07_settings.cjs
@@ -96,6 +96,27 @@ const modals = [];
 const plans = [];
 const calls = [];
 let failConfirm = false;
+const SCALES = {
+  scales: {
+    longitudinal: { x: 1000, y: 200 },
+    cross: { x: 100, y: 100 },
+    mass_haul: { x: null, y: 50000 },
+    development: { x: null, y: null },
+  },
+  defaults: {
+    longitudinal: { x: 1000, y: 200 },
+    cross: { x: 100, y: 100 },
+    mass_haul: { x: null, y: 50000 },
+    development: { x: null, y: null },
+  },
+  ranges: {
+    longitudinal: { x: [100, 10000], y: [10, 2000] },
+    cross: { x: [10, 1000], y: [10, 1000] },
+    mass_haul: { x: [100, 20000], y: [1000, 1000000] },
+    development: { x: [10, 10000], y: [10, 10000] },
+  },
+  saved: { longitudinal: 2, cross: 0, mass_haul: 0, development: 0 },
+};
 let answer = true;
 
 const button = (opts) => {
@@ -118,13 +139,24 @@ const STUBS = {
       label.className = "ui-field__label";
       label.textContent = opts.label;
       root.append(label, input);
-      return { root, input };
+      const setError = (msg) => (input.error = msg ?? null);
+      return { root, input, setError };
     },
     showToast: (message, kind) => toasts.push([kind, message]),
     showLoadingOverlay: () => calls.push(["overlay+"]),
     hideLoadingOverlay: () => calls.push(["overlay-"]),
     showConfirmDialog: async (message) => (calls.push(["ask", message]), answer),
   },
+  "@ui/ui_template_checkbox": {
+    createCheckbox: (text) => {
+      const root = new FakeNode("label");
+      root.className = "ui-checkbox";
+      const input = new FakeNode("input");
+      input.checked = false;
+      root.append(input);
+      return { root, input };
+    },
+  },
   "@ui/ui_template_modal": {
     openModal: (opts) => {
       const body = new FakeNode("div");
@@ -152,6 +184,9 @@ const STUBS = {
       return { all_confirmed: true };
     },
     invalidateDesignDrawing: async (projectId, id) => calls.push(["invalidate", id]),
+    // 485-2 축척 — 범위 · 기본은 서버(`_Router_Support_Scale.py`)와 같은 값
+    fetchDrawingScales: async () => JSON.parse(JSON.stringify(SCALES)),
+    saveDrawingScales: async (projectId, scales) => calls.push(["scales", scales]),
   },
 };
 
@@ -274,12 +309,14 @@ const drawings = [
   openDrawingSettings("cross", deps);
   await new Promise((r) => setTimeout(r, 0));
   const cross = modals.at(-1);
-  const crossInputs = all(cross.body).filter((n) => n.tagName === "INPUT");
+  const layoutNode = byClass(cross.body, "b07-cross-layout")[0];
+  const crossInputs = all(layoutNode).filter((n) => n.tagName === "INPUT");
   out.crossModal = {
     title: cross.opts.title,
-    labels: byClass(cross.body, "ui-field__label").map((n) => n.textContent),
+    labels: byClass(layoutNode, "ui-field__label").map((n) => n.textContent),
     values: crossInputs.map((n) => n.value),
-    buttons: all(cross.body)
+    scaleTitle: texts(byClass(cross.body, "b07-scale")[0])[0],
+    buttons: all(layoutNode)
       .filter((n) => n.tagName === "BUTTON")
       .map((n) => [n.textContent, n.disabled]),
     guideLast: byClass(cross.body, "b07-cross-layout")[0].children.at(-1) === guideToggle,
@@ -287,7 +324,7 @@ const drawings = [
     notes: texts(cross.body).filter((t) => t.startsWith("지금 도면")),
   };
   crossInputs[0].value = "2";
-  all(cross.body)
+  all(layoutNode)
     .find((n) => n.textContent === "이 장")
     .click();
   out.crossSave = { saved, closed: !cross.open };
@@ -318,6 +355,115 @@ const drawings = [
   openDrawingSettings("cross", deps);
   out.standardInCross = !modals.at(-1).opts.actions[0].disabled;
 
+  // ── 축척 칸(485-2) ─────────────────────────────────────────────────────
+  const closedCalls = [];
+  const scaleDeps = { ...deps, plan: { projectId: "p1", onClosed: (...a) => closedCalls.push(a) } };
+  const tick = () => new Promise((r) => setTimeout(r, 0));
+  const scaleOf = async (kind) => {
+    openDrawingSettings(kind, scaleDeps);
+    await tick();
+    const modal = modals.at(-1);
+    const section = byClass(modal.body, "b07-scale")[0];
+    const inputs = all(section).filter(
+      (n) => n.tagName === "INPUT" && !n.parent.classList.contains("ui-checkbox"),
+    );
+    const autos = byClass(section, "ui-checkbox").map((n) => n.children[0]);
+    const btn = (label) =>
+      all(section).find((n) => n.tagName === "BUTTON" && n.textContent === label);
+    const type = (input, value) => {
+      input.value = value;
+      input.listeners.input.forEach((h) => h());
+    };
+    const toggle = (box) => {
+      box.checked = !box.checked;
+      box.listeners.change.forEach((h) => h());
+    };
+    const state = () => ({
+      values: inputs.map((n) => n.value),
+      errors: inputs.map((n) => n.error ?? null),
+      disabled: inputs.map((n) => !!n.disabled),
+      autos: autos.map((n) => n.checked),
+      save: !btn("축척 저장").disabled,
+    });
+    return { modal, section, inputs, autos, btn, type, toggle, state };
+  };
+  const scale = {};
+  current = drawings[2]; // longitudinal
+  let s = await scaleOf("longitudinal");
+  scale.longLabels = byClass(s.section, "ui-field__label").map((n) => n.textContent);
+  scale.longStart = s.state();
+  s.type(s.inputs[0], "50");
+  scale.longLow = s.state();
+  s.type(s.inputs[0], "500.5");
+  scale.longFrac = s.state();
+  s.type(s.inputs[0], "500");
+  scale.longOk = s.state();
+  calls.length = 0;
+  answer = false;
+  s.btn("축척 저장").click();
+  await tick();
+  scale.cancel = { calls: calls.map((c) => c[0]), open: s.modal.open, closed: closedCalls.length };
+  answer = true;
+  calls.length = 0;
+  s.btn("축척 저장").click();
+  await tick();
+  await tick();
+  scale.save = {
+    ask: calls.find((c) => c[0] === "ask")?.[1],
+    sent: calls.find((c) => c[0] === "scales")?.[1],
+    open: s.modal.open,
+    closed: [...closedCalls],
+  };
+  s = await scaleOf("longitudinal");
+  s.type(s.inputs[1], "300");
+  s.btn("기본값").click();
+  scale.reset = s.state();
+  calls.length = 0;
+  const toastAt = toasts.length;
+  s.btn("축척 저장").click();
+  await tick();
+  scale.same = { calls: calls.length, toasts: toasts.slice(toastAt).map((t) => t[1]) };
+
+  s = await scaleOf("mass_haul");
+  scale.massStart = s.state();
+  s.toggle(s.autos[0]);
+  scale.massManual = s.state();
+  s.type(s.inputs[0], "2000");
+  scale.massTyped = s.state();
+  calls.length = 0;
+  s.btn("축척 저장").click();
+  await tick();
+  await tick();
+  scale.massSent = {
+    ask: calls.filter((c) => c[0] === "ask").length,
+    sent: calls.find((c) => c[0] === "scales")?.[1],
+  };
+  s = await scaleOf("mass_haul");
+  s.toggle(s.autos[0]);
+  s.toggle(s.autos[0]);
+  scale.massBack = s.state();
+
+  s = await scaleOf("development");
+  scale.dev = s.state();
+  openDrawingSettings("structure", scaleDeps);
+  scale.structure = byClass(modals.at(-1).body, "b07-scale").length;
+  out.scale = scale;
+  const Check = loadTs(path.join(B07, "logic", "B07_DesignDetail_Scale_Check.ts"));
+  out.readAxis = [
+    ["1,000", false],
+    [" 99 ", false],
+    ["10001", false],
+    ["12.5", false],
+    ["", false],
+    ["abc", false],
+    ["", true],
+  ].map(([raw, auto]) => Check.readScaleAxis(raw, auto, [100, 10000]));
+  out.toSend = [
+    Check.scaleToSend(200, 200),
+    Check.scaleToSend(500, 200),
+    Check.scaleToSend(null, null),
+  ];
+
   // ── 저장 묶음 ────────────────────────────────────────────────────────────
   const tabsOf = (list, activeId) => ({
     tabs: () => list,
diff --git a/resources/tester/test_280_5_b07_settings.py b/resources/tester/test_280_5_b07_settings.py
index 7ff3cc559..69ba47d16 100644
--- a/resources/tester/test_280_5_b07_settings.py
+++ b/resources/tester/test_280_5_b07_settings.py
@@ -83,6 +83,7 @@ def test_횡단_모달은_배치_칸_표_배율_안내선(out):
     assert cross["guideLast"] is True
     assert cross["head"] == [["원본에서 다시 그리기", False]]
     assert cross["notes"] == ["지금 도면: cross_s1"]
+    assert cross["scaleTitle"] == "축척 — 횡단도 장(표준 횡단면도 뺌)"
     saved = out["crossSave"]
     assert saved["closed"] is True
     assert saved["saved"] == [[{"default": [4, 4], "sheets": {"1": [2, 2]}, "table_scale": 1.2}, 1]]
@@ -93,7 +94,7 @@ def test_구조물_종단_평면도_모달(out):
     assert structure["title"] == "구조물 도면 설정"
     assert structure["notes"] == ["M02 그림 — 축척 없음"]
     assert structure["head"][0][1] is True  # 다른 묶음 도면을 연 중 = 꺼짐
-    assert out["longModal"] == {"title": "종단도 설정", "bodyKids": 0}  # 축척 칸은 485-2
+    assert out["longModal"] == {"title": "종단도 설정", "bodyKids": 1}  # 축척 칸(485-2)
     assert out["planModal"] == {"viaManager": True, "head": [["원본에서 다시 그리기", False]]}
     assert out["planRedraw"] == {"redraws": 1, "closed": True}
     assert out["standardInCross"] is True
@@ -216,3 +217,48 @@ def test_서버_단계_완료(monkeypatch, tmp_path: Path) -> None:
 
     monkeypatch.setattr(router, "_confirmed_source", blocked)
     assert asyncio.run(router.complete_design_stage(project)).status_code == 409
+
+
+RANGE = "1/100~1/10,000 사이 정수"
+
+
+def test_485_2_축척_칸_판정(out):
+    assert out["readAxis"] == [1000, RANGE, RANGE, RANGE, RANGE, RANGE, None]  # 자동 = null
+    assert out["toSend"] == [None, 500, None]  # 기본과 같으면 null
+
+
+def test_485_2_종단_축척_저장(out):
+    scale = out["scale"]
+    assert scale["longLabels"] == ["X(가로) 1/", "Y(세로) 1/"]
+    assert scale["longStart"]["values"] == ["1000", "200"]
+    assert scale["longStart"]["autos"] == []  # 종단 = 자동 없음
+    for bad in ("longLow", "longFrac"):  # 범위 밖 · 소수 = 붉음 + 저장 꺼짐
+        assert scale[bad]["errors"] == [RANGE, None]
+        assert scale[bad]["save"] is False
+    assert scale["longOk"]["errors"] == [None, None] and scale["longOk"]["save"] is True
+    # 저장본 2장 — 물음 [취소] = 요청 없음 · 모달 그대로
+    assert scale["cancel"] == {"calls": ["ask"], "open": True, "closed": 0}
+    save = scale["save"]
+    assert "저장본 2장" in save["ask"]
+    assert save["sent"] == {"longitudinal": {"x": 500, "y": None}}  # Y = 기본 → null
+    assert save["open"] is False
+    assert save["closed"] == [[True, "longitudinal"]]  # 화면 다시 세움 · 같은 도면
+    assert scale["reset"]["values"] == ["1000", "200"]  # [기본값] = 칸만
+    assert scale["same"] == {"calls": 0, "toasts": ["바뀐 축척이 없습니다."]}
+
+
+def test_485_2_토적_전개도_자동(out):
+    scale = out["scale"]
+    assert scale["massStart"] == {
+        "values": ["", "50000"],
+        "errors": [None, None],
+        "disabled": [True, False],
+        "autos": [True],
+        "save": True,
+    }
+    assert scale["massManual"]["errors"][0] and scale["massManual"]["save"] is False  # 빈 칸
+    assert scale["massTyped"]["save"] is True
+    assert scale["massSent"] == {"ask": 0, "sent": {"mass_haul": {"x": 2000, "y": None}}}
+    assert scale["massBack"]["autos"] == [True] and scale["massBack"]["save"] is True
+    assert scale["dev"]["autos"] == [True, True] and scale["dev"]["disabled"] == [True, True]
+    assert scale["structure"] == 0  # 구조물 = 축척 칸 없음