diff --git a/web/src/api/form_sheet.js b/web/src/api/form_sheet.js
index 7ac4ecd..c048a29 100644
--- a/web/src/api/form_sheet.js
+++ b/web/src/api/form_sheet.js
@@ -4,6 +4,9 @@ export const FormsSheetApi = {
 	get(formId, sheetName, params) {
 		return api.get(`/form/${formId}/sheet/${sheetName}`, params).then((r) => r.data);
 	},
+	getFormulas(formId, sheetName) {
+		return api.get(`/form/${formId}/sheet/${encodeURIComponent(sheetName)}/formulas`).then((r) => r.data.result);
+	},
 	export(formId, sheetName, params = {}) {
 		return api.get(`export/form/${formId}/sheet/${sheetName}`, {
 			params,
diff --git a/web/src/api/projects.js b/web/src/api/projects.js
index e7c8ca8..cbbdc2f 100644
--- a/web/src/api/projects.js
+++ b/web/src/api/projects.js
@@ -35,6 +35,9 @@ export const ProjectsApi = {
 	getTableData: (id, sheetName, year) => {
 		return api.get(`/projects/${id}/report/${year}/${sheetName}`).then((r) => r.data);
 	},
+	getReportFormulas: (id, year, reportType) => {
+		return api.get(`/projects/${id}/report/${year}/${reportType}/formulas`).then((r) => r.data.result);
+	},
 	getSummary: (id) => {
 		return api.get(`/projects/${id}/summary`).then((r) => r.data);
 	},
diff --git a/web/src/components/RealtimeTable/utils/cellFormulaUtils.js b/web/src/components/RealtimeTable/utils/cellFormulaUtils.js
new file mode 100644
index 0000000..0964c8d
--- /dev/null
+++ b/web/src/components/RealtimeTable/utils/cellFormulaUtils.js
@@ -0,0 +1,75 @@
+// AURORA-1896: чистые утилиты карты формул ячеек (без React/MUI/constants.jsx).
+
+export const formulaKey = (lineId, column) => `${lineId}|${column}`;
+
+export const buildFormulaMap = (list) => {
+	const map = new Map();
+	for (const item of list ?? []) {
+		map.set(formulaKey(item.line_id, item.column), item);
+	}
+	return map;
+};
+
+// Возвращает новый Map; вход не мутируется. Фоновые события без ячейки
+// (синхронизация сателлитов: data:{source_sheet}) карту не меняют.
+export const applyFormulaEvent = (map, data) => {
+	if (!data || data.line_id == null || data.column == null) return map;
+	const next = new Map(map);
+	const key = formulaKey(data.line_id, data.column);
+	if (typeof data.formula === 'string' && data.formula) {
+		next.set(key, {
+			line_id: data.line_id,
+			column: data.column,
+			expression: data.formula,
+			value: Number(data.value),
+			updated_by: data.formula_meta?.updated_by,
+			updated_at: data.formula_meta?.updated_at,
+		});
+	} else {
+		next.delete(key);
+	}
+	return next;
+};
+
+const toFiniteNumber = (v) => {
+	if (v == null || (typeof v === 'string' && v.trim() === '')) return null;
+	const n = Number(v);
+	return Number.isFinite(n) ? n : null;
+};
+
+export const isFormulaActual = (formula, value) => {
+	if (!formula) return false;
+	const a = toFiniteNumber(formula.value);
+	const b = toFiniteNumber(value);
+	if (a === null || b === null) return false;
+	return Math.abs(a - b) <= 1e-9;
+};
+
+const pad = (n) => String(n).padStart(2, '0');
+
+export const formatFormulaHint = (formula) => {
+	const author = formula.updated_by;
+	const name = author?.full_name || `Пользователь #${author?.id}`;
+	const parts = [`=${formula.expression}`, name];
+	if (formula.updated_at) {
+		const d = new Date(formula.updated_at);
+		if (!Number.isNaN(d.getTime())) {
+			parts.push(`${pad(d.getDate())}.${pad(d.getMonth() + 1)}.${d.getFullYear()} ${pad(d.getHours())}:${pad(d.getMinutes())}`);
+		}
+	}
+	return parts.join(' · ');
+};
+
+export const clearLegacyFormulaStorage = (storage) => {
+	try {
+		const toRemove = [];
+		for (let i = 0; i < storage.length; i++) {
+			const k = storage.key(i);
+			if (typeof k === 'string' && k.startsWith('formula_')) toRemove.push(k);
+		}
+		for (const k of toRemove) storage.removeItem(k);
+		return toRemove.length;
+	} catch {
+		return 0;
+	}
+};
diff --git a/web/src/components/RealtimeTable/utils/cellFormulaUtils.test.js b/web/src/components/RealtimeTable/utils/cellFormulaUtils.test.js
new file mode 100644
index 0000000..0320013
--- /dev/null
+++ b/web/src/components/RealtimeTable/utils/cellFormulaUtils.test.js
@@ -0,0 +1,110 @@
+import assert from 'node:assert/strict';
+import test from 'node:test';
+import {
+	applyFormulaEvent,
+	buildFormulaMap,
+	clearLegacyFormulaStorage,
+	formatFormulaHint,
+	formulaKey,
+	isFormulaActual,
+} from './cellFormulaUtils.js';
+
+const user = { id: 7, full_name: 'Иванов И.И.' };
+
+test('formulaKey склеивает line_id и column', () => {
+	assert.equal(formulaKey(5, 'q1'), '5|q1');
+});
+
+test('buildFormulaMap строит карту по ключу', () => {
+	const map = buildFormulaMap([{ line_id: 1, column: 'a', expression: '1+2', value: 3, updated_by: user, updated_at: 'x' }]);
+	assert.equal(map.size, 1);
+	assert.equal(map.get('1|a').expression, '1+2');
+	assert.equal(buildFormulaMap(null).size, 0);
+});
+
+test('applyFormulaEvent: строка записывает формулу', () => {
+	const map = new Map();
+	const next = applyFormulaEvent(map, {
+		line_id: 1,
+		column: 'a',
+		value: '150',
+		formula: '100+50',
+		formula_meta: { updated_by: user, updated_at: '2026-10-27T14:03:00' },
+	});
+	assert.notEqual(next, map);
+	assert.equal(map.size, 0);
+	assert.deepEqual(next.get('1|a'), {
+		line_id: 1,
+		column: 'a',
+		expression: '100+50',
+		value: 150,
+		updated_by: user,
+		updated_at: '2026-10-27T14:03:00',
+	});
+});
+
+test('applyFormulaEvent: formula null удаляет, вход не мутируется', () => {
+	const map = buildFormulaMap([{ line_id: 1, column: 'a', expression: '1', value: 1 }]);
+	const next = applyFormulaEvent(map, { line_id: 1, column: 'a', value: 2, formula: null });
+	assert.equal(next.size, 0);
+	assert.equal(map.size, 1);
+});
+
+test('applyFormulaEvent: без поля formula удаляет', () => {
+	const map = buildFormulaMap([{ line_id: 1, column: 'a', expression: '1', value: 1 }]);
+	const next = applyFormulaEvent(map, { line_id: 1, column: 'a', value: 2 });
+	assert.equal(next.size, 0);
+});
+
+test('applyFormulaEvent: фоновое событие без line_id/column возвращает ту же карту', () => {
+	const map = buildFormulaMap([{ line_id: 1, column: 'a', expression: '1', value: 1 }]);
+	assert.equal(applyFormulaEvent(map, { source_sheet: 'AHR_RENT' }), map);
+	assert.equal(applyFormulaEvent(map, { line_id: 1, source_sheet: 'X' }), map);
+	assert.equal(map.size, 1);
+});
+
+test('isFormulaActual', () => {
+	const f = { expression: '100+50', value: 150 };
+	assert.equal(isFormulaActual(f, 150), true);
+	assert.equal(isFormulaActual(f, '150'), true);
+	assert.equal(isFormulaActual({ ...f, value: '150' }, 150.0000000001), true);
+	assert.equal(isFormulaActual({ ...f, value: 150 }, 151), false);
+	assert.equal(isFormulaActual(null, 150), false);
+	assert.equal(isFormulaActual({ ...f, value: 150 }, 'abc'), false);
+	assert.equal(isFormulaActual({ ...f, value: 150 }, null), false);
+	assert.equal(isFormulaActual({ ...f, value: 150 }, ''), false);
+});
+
+test('formatFormulaHint', () => {
+	assert.equal(
+		formatFormulaHint({ expression: '100+50', updated_by: user, updated_at: '2026-10-27T14:03:00' }),
+		'=100+50 · Иванов И.И. · 27.10.2026 14:03',
+	);
+	assert.equal(
+		formatFormulaHint({ expression: '1+1', updated_by: { id: 7 }, updated_at: '2026-10-27T14:03:00' }),
+		'=1+1 · Пользователь #7 · 27.10.2026 14:03',
+	);
+	assert.equal(formatFormulaHint({ expression: '1+1', updated_by: user }), '=1+1 · Иванов И.И.');
+});
+
+test('clearLegacyFormulaStorage', () => {
+	const keys = ['formula_v2_a', 'formula_x', 'other'];
+	const storage = {
+		get length() {
+			return keys.length;
+		},
+		key: (i) => keys[i] ?? null,
+		removeItem: (k) => {
+			keys.splice(keys.indexOf(k), 1);
+		},
+	};
+	assert.equal(clearLegacyFormulaStorage(storage), 2);
+	assert.deepEqual(keys, ['other']);
+	const broken = {
+		get length() {
+			throw new Error('denied');
+		},
+	};
+	assert.equal(clearLegacyFormulaStorage(broken), 0);
+	assert.equal(clearLegacyFormulaStorage(null), 0);
+});