diff --git a/index.html b/index.html
index a28bbef..3f2c7fc 100644
--- a/index.html
+++ b/index.html
@@ -201,6 +201,7 @@
       <main class="grid quantity" id="view-quantity" hidden>
         <aside class="panel piers" aria-labelledby="quantity-pier-title">
           <p id="quantity-pier-title" class="lbl">교각 목록</p>
+          <button id="quantity-all" class="pier-name" type="button" aria-pressed="true">전체</button>
           <ul id="quantity-pier-items" class="pier-items"></ul>
           <p class="pnote" id="quantity-note"></p>
         </aside>
diff --git a/src/core/quantity-scope.ts b/src/core/quantity-scope.ts
new file mode 100644
index 0000000..9a29148
--- /dev/null
+++ b/src/core/quantity-scope.ts
@@ -0,0 +1,14 @@
+/** One pier as the 재료표 scope sees it. */
+export interface QuantityPier {
+  name: string;
+  hasModel: boolean;
+}
+
+/**
+ * The piers the ④ 재료표 shows: every pier with a model when 전체 is on, otherwise only the chosen pier
+ * (교각 목록에서 고른 교각). A chosen pier without a model shows nothing.
+ */
+export function quantityTargetNames(piers: QuantityPier[], all: boolean, active: string | null): string[] {
+  if (all) return piers.filter((p) => p.hasModel).map((p) => p.name);
+  return piers.filter((p) => p.hasModel && p.name === active).map((p) => p.name);
+}
diff --git a/src/main.ts b/src/main.ts
index 55e4cdb..bd8f1ed 100644
--- a/src/main.ts
+++ b/src/main.ts
@@ -10,6 +10,7 @@ import { EDITABLE_FIELDS, FIELD_LABELS, overrideKeys, pendingKeys, revertDraft,
 import { adjustRow, layoutText, resolveRowCounts, rowLayout, totalPiles } from './core/piles';
 import { applyCopy, COPY_ITEMS, planCopy, type CopyItem } from './core/copy';
 import { copyCandidates, copyItemsFor, copyItemsWithOverrides, hasCopyItems, selectedTargets, type CopyCandidate } from './core/copy-targets';
+import { quantityTargetNames } from './core/quantity-scope';
 import { pileGeometry } from './core/geometry';
 import { rebarSummary, type RebarRow } from './core/rebar/summary';
 import { shearSegments } from './core/rebar/coping';
@@ -122,6 +123,8 @@ const state = {
   stage: 'shape' as Stage,
   /** 전체 보기 on ① 형상 생성: every pier's concrete in one frame (콘크리트만). On by default (승인 2026-10-27). */
   allView: true,
+  /** ④ 재료표 scope: true = every pier (전체), false = the pier chosen in the list. */
+  quantityAll: true,
   /** ③ 공통 설정 (fck · fy). */
   material: { ...DEFAULT_MATERIAL } as Material,
   /** ② 부재별 fck. A member without an entry uses the 공통 fck (③). Initial values from 교각도 (025·026, 승인 2026-10-27): 기둥·코핑 40, 기초 27. */
@@ -437,6 +440,7 @@ function renderPierRows(list: HTMLUListElement, mode: Stage): void {
     name.setAttribute('aria-pressed', String(pier.input.name === state.active));
     name.addEventListener('click', () => {
       state.active = pier.input.name;
+      state.quantityAll = false;
       state.rebarSelection = new Set();
       setupScene();
       renderAll();
@@ -1766,8 +1770,10 @@ function renderQuantityLink(box: HTMLElement, rows: RebarRow[]): void {
 }
 
 /** ④ 재료표: the 철근재료표 of each target pier, bars by 강종 → 직경 → 번호, with subtotals and the totals. */
+/** The piers the 재료표 shows: 전체, or the pier chosen in the list. */
 function quantityTargets(): Pier[] {
-  return state.piers.filter((p) => p.model);
+  const names = new Set(quantityTargetNames(state.piers.map((p) => ({ name: p.input.name, hasModel: p.model !== null })), state.quantityAll, state.active));
+  return state.piers.filter((p) => names.has(p.input.name));
 }
 
 /** Length cell of a 재료표 line: the length, or 여러 길이 with the pieces on hover. */
@@ -1806,10 +1812,14 @@ function renderQuantityScreen(): void {
   const body = $<HTMLDivElement>('quantity-body');
   body.replaceChildren();
   renderPierRows($<HTMLUListElement>('quantity-pier-items'), 'quantity');
+  const allButton = $<HTMLButtonElement>('quantity-all');
+  const generated = state.piers.filter((p) => p.model).length;
+  allButton.textContent = `전체 (${generated}기)`;
+  allButton.setAttribute('aria-pressed', String(state.quantityAll));
   const targets = quantityTargets();
-  $('step4-status').textContent = targets.length ? `${targets.length}기` : '예정';
+  $('step4-status').textContent = targets.length ? (state.quantityAll ? `${targets.length}기` : targets[0].input.name) : '예정';
   $('quantity-note').textContent = targets.length
-    ? `${targets.length}기 · 할증 ${state.material.waste}% (기본 0%, 가정). 삿갓 길이는 h − 100으로 가정(Q-K5). 체크한 교각 기준이고, 체크가 없으면 현재 교각입니다.`
+    ? `${state.quantityAll ? `전체 ${targets.length}기` : targets[0].input.name} · 할증 ${state.material.waste}% (기본 0%, 가정). 삿갓 길이는 h − 100으로 가정(Q-K5). 교각 목록에서 고른 교각만 보며, 전체를 누르면 모든 교각을 보여 줍니다.`
     : '계산된 교각이 없습니다. 교각을 생성하세요.';
   let kg = 0;
   let kgWithWaste = 0;
@@ -1845,6 +1855,10 @@ function exportQuantityWorkbook(): void {
   XLSX.writeFile(wb, `${state.project.bridge || '교량'}_철근재료표.xlsx`);
 }
 
+$<HTMLButtonElement>('quantity-all').addEventListener('click', () => {
+  state.quantityAll = true;
+  renderAll();
+});
 $<HTMLButtonElement>('quantity-export').addEventListener('click', exportQuantityWorkbook);
 $<HTMLButtonElement>('quantity-print').addEventListener('click', () => window.print());
 
diff --git a/tests/quantity-scope.test.ts b/tests/quantity-scope.test.ts
new file mode 100644
index 0000000..960e3a1
--- /dev/null
+++ b/tests/quantity-scope.test.ts
@@ -0,0 +1,26 @@
+import { describe, expect, it } from 'vitest';
+import { quantityTargetNames } from '../src/core/quantity-scope';
+
+const piers = [
+  { name: 'P1', hasModel: true },
+  { name: 'P2', hasModel: true },
+  { name: 'P3', hasModel: false },
+];
+
+describe('quantityTargetNames (④ 재료표 범위)', () => {
+  it('is every pier with a model when 전체 is on', () => {
+    expect(quantityTargetNames(piers, true, 'P2')).toEqual(['P1', 'P2']);
+  });
+
+  it('is only the chosen pier when 전체 is off', () => {
+    expect(quantityTargetNames(piers, false, 'P2')).toEqual(['P2']);
+  });
+
+  it('is empty when the chosen pier has no model', () => {
+    expect(quantityTargetNames(piers, false, 'P3')).toEqual([]);
+  });
+
+  it('is empty when no pier is chosen and 전체 is off', () => {
+    expect(quantityTargetNames(piers, false, null)).toEqual([]);
+  });
+});