diff --git a/tests/services/category.service.test.ts b/tests/services/category.service.test.ts
new file mode 100644
index 0000000..806d51a
--- /dev/null
+++ b/tests/services/category.service.test.ts
@@ -0,0 +1,98 @@
+import { describe, it, expect, beforeEach } from "bun:test";
+import { createTestDb } from "../helpers/db.ts";
+import {
+  getAllCategories,
+  createCategory,
+  updateCategory,
+  deleteCategory,
+} from "../../src/server/services/category.service.ts";
+import { createItem } from "../../src/server/services/item.service.ts";
+import { items } from "../../src/db/schema.ts";
+import { eq } from "drizzle-orm";
+
+describe("Category Service", () => {
+  let db: ReturnType<typeof createTestDb>;
+
+  beforeEach(() => {
+    db = createTestDb();
+  });
+
+  describe("createCategory", () => {
+    it("creates with name and emoji", () => {
+      const cat = createCategory(db, { name: "Shelter", emoji: "\u{26FA}" });
+
+      expect(cat).toBeDefined();
+      expect(cat!.id).toBeGreaterThan(0);
+      expect(cat!.name).toBe("Shelter");
+      expect(cat!.emoji).toBe("\u{26FA}");
+    });
+
+    it("uses default emoji if not provided", () => {
+      const cat = createCategory(db, { name: "Cooking" });
+
+      expect(cat).toBeDefined();
+      expect(cat!.emoji).toBe("\u{1F4E6}");
+    });
+  });
+
+  describe("getAllCategories", () => {
+    it("returns all categories", () => {
+      createCategory(db, { name: "Shelter", emoji: "\u{26FA}" });
+      createCategory(db, { name: "Cooking", emoji: "\u{1F373}" });
+
+      const all = getAllCategories(db);
+      // Includes seeded Uncategorized + 2 new
+      expect(all.length).toBeGreaterThanOrEqual(3);
+    });
+  });
+
+  describe("updateCategory", () => {
+    it("renames category", () => {
+      const cat = createCategory(db, { name: "Shelter", emoji: "\u{26FA}" });
+      const updated = updateCategory(db, cat!.id, { name: "Sleep System" });
+
+      expect(updated).toBeDefined();
+      expect(updated!.name).toBe("Sleep System");
+      expect(updated!.emoji).toBe("\u{26FA}");
+    });
+
+    it("changes emoji", () => {
+      const cat = createCategory(db, { name: "Shelter", emoji: "\u{26FA}" });
+      const updated = updateCategory(db, cat!.id, { emoji: "\u{1F3E0}" });
+
+      expect(updated).toBeDefined();
+      expect(updated!.emoji).toBe("\u{1F3E0}");
+    });
+
+    it("returns null for non-existent id", () => {
+      const result = updateCategory(db, 9999, { name: "Ghost" });
+      expect(result).toBeNull();
+    });
+  });
+
+  describe("deleteCategory", () => {
+    it("reassigns items to Uncategorized (id=1) then deletes", () => {
+      const shelter = createCategory(db, { name: "Shelter", emoji: "\u{26FA}" });
+      createItem(db, { name: "Tent", categoryId: shelter!.id });
+      createItem(db, { name: "Tarp", categoryId: shelter!.id });
+
+      const result = deleteCategory(db, shelter!.id);
+      expect(result.success).toBe(true);
+
+      // Items should now be in Uncategorized (id=1)
+      const reassigned = db
+        .select()
+        .from(items)
+        .where(eq(items.categoryId, 1))
+        .all();
+      expect(reassigned).toHaveLength(2);
+      expect(reassigned.map((i) => i.name).sort()).toEqual(["Tarp", "Tent"]);
+    });
+
+    it("cannot delete Uncategorized (id=1)", () => {
+      const result = deleteCategory(db, 1);
+      expect(result.success).toBe(false);
+      expect(result.error).toBeDefined();
+    });
+  });
+});
diff --git a/tests/services/item.service.test.ts b/tests/services/item.service.test.ts
new file mode 100644
index 0000000..cb569be
--- /dev/null
+++ b/tests/services/item.service.test.ts
@@ -0,0 +1,127 @@
+import { describe, it, expect, beforeEach } from "bun:test";
+import { createTestDb } from "../helpers/db.ts";
+import {
+  getAllItems,
+  getItemById,
+  createItem,
+  updateItem,
+  deleteItem,
+} from "../../src/server/services/item.service.ts";
+
+describe("Item Service", () => {
+  let db: ReturnType<typeof createTestDb>;
+
+  beforeEach(() => {
+    db = createTestDb();
+  });
+
+  describe("createItem", () => {
+    it("creates item with all fields, returns item with id and timestamps", () => {
+      const item = createItem(
+        db,
+        {
+          name: "Tent",
+          weightGrams: 1200,
+          priceCents: 35000,
+          categoryId: 1,
+          notes: "Ultralight 2-person",
+          productUrl: "https://example.com/tent",
+        },
+      );
+
+      expect(item).toBeDefined();
+      expect(item!.id).toBeGreaterThan(0);
+      expect(item!.name).toBe("Tent");
+      expect(item!.weightGrams).toBe(1200);
+      expect(item!.priceCents).toBe(35000);
+      expect(item!.categoryId).toBe(1);
+      expect(item!.notes).toBe("Ultralight 2-person");
+      expect(item!.productUrl).toBe("https://example.com/tent");
+      expect(item!.createdAt).toBeDefined();
+      expect(item!.updatedAt).toBeDefined();
+    });
+
+    it("only name and categoryId are required, other fields optional", () => {
+      const item = createItem(db, { name: "Spork", categoryId: 1 });
+
+      expect(item).toBeDefined();
+      expect(item!.name).toBe("Spork");
+      expect(item!.weightGrams).toBeNull();
+      expect(item!.priceCents).toBeNull();
+      expect(item!.notes).toBeNull();
+      expect(item!.productUrl).toBeNull();
+    });
+  });
+
+  describe("getAllItems", () => {
+    it("returns all items with category info joined", () => {
+      createItem(db, { name: "Tent", categoryId: 1 });
+      createItem(db, { name: "Sleeping Bag", categoryId: 1 });
+
+      const all = getAllItems(db);
+      expect(all).toHaveLength(2);
+      expect(all[0].categoryName).toBe("Uncategorized");
+      expect(all[0].categoryEmoji).toBeDefined();
+    });
+  });
+
+  describe("getItemById", () => {
+    it("returns single item or null", () => {
+      const created = createItem(db, { name: "Tent", categoryId: 1 });
+      const found = getItemById(db, created!.id);
+      expect(found).toBeDefined();
+      expect(found!.name).toBe("Tent");
+
+      const notFound = getItemById(db, 9999);
+      expect(notFound).toBeNull();
+    });
+  });
+
+  describe("updateItem", () => {
+    it("updates specified fields, sets updatedAt", () => {
+      const created = createItem(db, {
+        name: "Tent",
+        weightGrams: 1200,
+        categoryId: 1,
+      });
+
+      const updated = updateItem(db, created!.id, {
+        name: "Big Agnes Tent",
+        weightGrams: 1100,
+      });
+
+      expect(updated).toBeDefined();
+      expect(updated!.name).toBe("Big Agnes Tent");
+      expect(updated!.weightGrams).toBe(1100);
+    });
+
+    it("returns null for non-existent id", () => {
+      const result = updateItem(db, 9999, { name: "Ghost" });
+      expect(result).toBeNull();
+    });
+  });
+
+  describe("deleteItem", () => {
+    it("removes item from DB, returns deleted item", () => {
+      const created = createItem(db, {
+        name: "Tent",
+        categoryId: 1,
+        imageFilename: "tent.jpg",
+      });
+
+      const deleted = deleteItem(db, created!.id);
+      expect(deleted).toBeDefined();
+      expect(deleted!.name).toBe("Tent");
+      expect(deleted!.imageFilename).toBe("tent.jpg");
+
+      // Verify it's gone
+      const found = getItemById(db, created!.id);
+      expect(found).toBeNull();
+    });
+
+    it("returns null for non-existent id", () => {
+      const result = deleteItem(db, 9999);
+      expect(result).toBeNull();
+    });
+  });
+});
diff --git a/tests/services/totals.test.ts b/tests/services/totals.test.ts
new file mode 100644
index 0000000..09d2f9b
--- /dev/null
+++ b/tests/services/totals.test.ts
@@ -0,0 +1,79 @@
+import { describe, it, expect, beforeEach } from "bun:test";
+import { createTestDb } from "../helpers/db.ts";
+import { createItem } from "../../src/server/services/item.service.ts";
+import { createCategory } from "../../src/server/services/category.service.ts";
+import {
+  getCategoryTotals,
+  getGlobalTotals,
+} from "../../src/server/services/totals.service.ts";
+
+describe("Totals Service", () => {
+  let db: ReturnType<typeof createTestDb>;
+
+  beforeEach(() => {
+    db = createTestDb();
+  });
+
+  describe("getCategoryTotals", () => {
+    it("returns weight sum, cost sum, item count per category", () => {
+      const shelter = createCategory(db, { name: "Shelter", emoji: "\u{26FA}" });
+      createItem(db, {
+        name: "Tent",
+        weightGrams: 1200,
+        priceCents: 35000,
+        categoryId: shelter!.id,
+      });
+      createItem(db, {
+        name: "Tarp",
+        weightGrams: 300,
+        priceCents: 8000,
+        categoryId: shelter!.id,
+      });
+
+      const totals = getCategoryTotals(db);
+      expect(totals).toHaveLength(1); // Only Shelter has items
+      expect(totals[0].categoryName).toBe("Shelter");
+      expect(totals[0].totalWeight).toBe(1500);
+      expect(totals[0].totalCost).toBe(43000);
+      expect(totals[0].itemCount).toBe(2);
+    });
+
+    it("excludes empty categories (no items)", () => {
+      createCategory(db, { name: "Shelter", emoji: "\u{26FA}" });
+      // No items added
+      const totals = getCategoryTotals(db);
+      expect(totals).toHaveLength(0);
+    });
+  });
+
+  describe("getGlobalTotals", () => {
+    it("returns overall weight, cost, count", () => {
+      createItem(db, {
+        name: "Tent",
+        weightGrams: 1200,
+        priceCents: 35000,
+        categoryId: 1,
+      });
+      createItem(db, {
+        name: "Spork",
+        weightGrams: 20,
+        priceCents: 500,
+        categoryId: 1,
+      });
+
+      const totals = getGlobalTotals(db);
+      expect(totals).toBeDefined();
+      expect(totals!.totalWeight).toBe(1220);
+      expect(totals!.totalCost).toBe(35500);
+      expect(totals!.itemCount).toBe(2);
+    });
+
+    it("returns zeros when no items exist", () => {
+      const totals = getGlobalTotals(db);
+      expect(totals).toBeDefined();
+      expect(totals!.totalWeight).toBe(0);
+      expect(totals!.totalCost).toBe(0);
+      expect(totals!.itemCount).toBe(0);
+    });
+  });
+});