diff --git a/components.d.ts b/components.d.ts
index 3e65c3cc..b6f8bb74 100644
--- a/components.d.ts
+++ b/components.d.ts
@@ -83,6 +83,7 @@ declare module '@vue/runtime-core' {
     GitMemo: typeof import('./src/tools/git-memo/git-memo.vue')['default']
     'GitMemo.content': typeof import('./src/tools/git-memo/git-memo.content.md')['default']
     HashText: typeof import('./src/tools/hash-text/hash-text.vue')['default']
+    HddCalculator: typeof import('./src/tools/hdd-calculator/hdd-calculator.vue')['default']
     HmacGenerator: typeof import('./src/tools/hmac-generator/hmac-generator.vue')['default']
     'Home.page': typeof import('./src/pages/Home.page.vue')['default']
     HtmlEntities: typeof import('./src/tools/html-entities/html-entities.vue')['default']
@@ -130,19 +131,18 @@ declare module '@vue/runtime-core' {
     MetaTagGenerator: typeof import('./src/tools/meta-tag-generator/meta-tag-generator.vue')['default']
     MimeTypes: typeof import('./src/tools/mime-types/mime-types.vue')['default']
     NavbarButtons: typeof import('./src/components/NavbarButtons.vue')['default']
-    NCheckbox: typeof import('naive-ui')['NCheckbox']
     NCollapseTransition: typeof import('naive-ui')['NCollapseTransition']
     NConfigProvider: typeof import('naive-ui')['NConfigProvider']
     NDivider: typeof import('naive-ui')['NDivider']
     NEllipsis: typeof import('naive-ui')['NEllipsis']
+    NFormItem: typeof import('naive-ui')['NFormItem']
     NH1: typeof import('naive-ui')['NH1']
     NH3: typeof import('naive-ui')['NH3']
     NIcon: typeof import('naive-ui')['NIcon']
+    NInputNumber: typeof import('naive-ui')['NInputNumber']
     NLayout: typeof import('naive-ui')['NLayout']
     NLayoutSider: typeof import('naive-ui')['NLayoutSider']
     NMenu: typeof import('naive-ui')['NMenu']
-    NSpace: typeof import('naive-ui')['NSpace']
-    NTable: typeof import('naive-ui')['NTable']
     NumeronymGenerator: typeof import('./src/tools/numeronym-generator/numeronym-generator.vue')['default']
     OtpCodeGeneratorAndValidator: typeof import('./src/tools/otp-code-generator-and-validator/otp-code-generator-and-validator.vue')['default']
     PasswordStrengthAnalyser: typeof import('./src/tools/password-strength-analyser/password-strength-analyser.vue')['default']
@@ -161,6 +161,7 @@ declare module '@vue/runtime-core' {
     RouterView: typeof import('vue-router')['RouterView']
     RsaKeyPairGenerator: typeof import('./src/tools/rsa-key-pair-generator/rsa-key-pair-generator.vue')['default']
     SafelinkDecoder: typeof import('./src/tools/safelink-decoder/safelink-decoder.vue')['default']
+    SafelinkDecoder: typeof import('./src/tools/safelink-decoder/safelink-decoder.vue')['default']
     SlugifyString: typeof import('./src/tools/slugify-string/slugify-string.vue')['default']
     SpanCopyable: typeof import('./src/components/SpanCopyable.vue')['default']
     SqlPrettify: typeof import('./src/tools/sql-prettify/sql-prettify.vue')['default']
diff --git a/src/tools/hdd-calculator/hdd-calculator.service.test.ts b/src/tools/hdd-calculator/hdd-calculator.service.test.ts
new file mode 100644
index 00000000..8c6d27f2
--- /dev/null
+++ b/src/tools/hdd-calculator/hdd-calculator.service.test.ts
@@ -0,0 +1,12 @@
+import { describe, expect, it } from 'vitest';
+import { getRealSize } from './hdd-calculator.service';
+
+describe('hdd-calculator', () => {
+  it('Convert Claimed Size to Real Size', async () => {
+    expect(getRealSize(10, 'gb', 'tb')).to.equal(0.009094947017729282);
+    expect(getRealSize(10, 'pb', 'mb')).to.equal(9536743164.0625);
+    expect(getRealSize(100, 'tb', 'gb')).to.equal(93132.25746154785);
+    expect(getRealSize(1, 'pb', 'gb')).to.equal(931322.5746154785);
+    expect(getRealSize(1000, 'tb', 'gb')).to.equal(931322.5746154785);
+  });
+});
diff --git a/src/tools/hdd-calculator/hdd-calculator.service.ts b/src/tools/hdd-calculator/hdd-calculator.service.ts
new file mode 100644
index 00000000..e42f8566
--- /dev/null
+++ b/src/tools/hdd-calculator/hdd-calculator.service.ts
@@ -0,0 +1,14 @@
+const unitsConversion = {
+  kb: { dec: 1_000, bin: 1024 },
+  mb: { dec: 1_000_000, bin: 1024 * 1024 },
+  gb: { dec: 1_000_000_000, bin: 1024 * 1024 * 1024 },
+  tb: { dec: 1_000_000_000_000, bin: 1024 * 1024 * 1024 * 1024 },
+  pb: { dec: 1_000_000_000_000_000, bin: 1024 * 1024 * 1024 * 1024 * 1024 },
+};
+
+export type Units = 'kb' | 'mb' | 'gb' | 'tb' | 'pb';
+export function getRealSize(claimedCapacity: number, claimedUnit: Units, toUnit: Units) {
+  const fromUnit = unitsConversion[claimedUnit];
+  const toUnitBin = unitsConversion[toUnit].bin;
+  return claimedCapacity * fromUnit.dec / toUnitBin;
+};
diff --git a/src/tools/hdd-calculator/hdd-calculator.vue b/src/tools/hdd-calculator/hdd-calculator.vue
new file mode 100644
index 00000000..b5fcba2f
--- /dev/null
+++ b/src/tools/hdd-calculator/hdd-calculator.vue
@@ -0,0 +1,45 @@
+<script setup lang="ts">
+import InputCopyable from '../../components/InputCopyable.vue';
+import type { Units } from './hdd-calculator.service';
+import { getRealSize } from './hdd-calculator.service';
+
+const dec_units = [
+  { value: 'kb', label: 'kB' },
+  { value: 'mb', label: 'MB' },
+  { value: 'gb', label: 'GB' },
+  { value: 'tb', label: 'TB' },
+  { value: 'pb', label: 'PB' },
+];
+const bin_units = [
+  { value: 'kb', label: 'KiB' },
+  { value: 'mb', label: 'MiB' },
+  { value: 'gb', label: 'GiB' },
+  { value: 'tb', label: 'TiB' },
+  { value: 'pb', label: 'PiB' },
+];
+
+const claimedCapacity = ref(1);
+const claimedUnit = ref('tb');
+</script>
+
+<template>
+  <div>
+    <n-form-item label="Claimed Capacity:">
+      <n-input-number v-model:value="claimedCapacity" :min="1" />
+    </n-form-item>
+    <c-select
+      v-model:value="claimedUnit"
+      label="Unit:"
+      :options="dec_units"
+    />
+
+    <n-divider />
+
+    <InputCopyable
+      v-for="({ value, label }) in bin_units"
+      :key="value"
+      :label="`Capacity in ${label}:`"
+      :value="getRealSize(claimedCapacity, claimedUnit as Units, value as Units).toFixed(5)"
+    />
+  </div>
+</template>
diff --git a/src/tools/hdd-calculator/index.ts b/src/tools/hdd-calculator/index.ts
new file mode 100644
index 00000000..e3b1e765
--- /dev/null
+++ b/src/tools/hdd-calculator/index.ts
@@ -0,0 +1,14 @@
+import { DeviceDesktop } from '@vicons/tabler';
+import { defineTool } from '../tool';
+
+export const tool = defineTool({
+  name: 'HDD calculator',
+  path: '/hdd-calculator',
+  description: 'Storage device manufacturers report capacities in decimal form (like GB), while operating systems and other software uses binary form (GiB), although still incorrectly using the decimal unit (GiB). This tool converts decimal form capacity into various binary forms.',
+  keywords: ['hdd', 'calculator', 'size', 'conversion', 'binary', 'decimal',
+    'gb', 'mb', 'tb',
+    'gigabyte', 'gibibyte', 'megabyte', 'mebibyte', 'terabyte', 'tebibyte'],
+  component: () => import('./hdd-calculator.vue'),
+  icon: DeviceDesktop,
+  createdAt: new Date('2024-04-07'),
+});
diff --git a/src/tools/index.ts b/src/tools/index.ts
index 388cfaf4..10a1a5cd 100644
--- a/src/tools/index.ts
+++ b/src/tools/index.ts
@@ -7,6 +7,7 @@ import { tool as asciiTextDrawer } from './ascii-text-drawer';
 
 import { tool as textToUnicode } from './text-to-unicode';
 import { tool as safelinkDecoder } from './safelink-decoder';
+import { tool as hddCalculator } from './hdd-calculator';
 import { tool as xmlToJson } from './xml-to-json';
 import { tool as jsonToXml } from './json-to-xml';
 import { tool as regexTester } from './regex-tester';
@@ -113,6 +114,7 @@ export const toolsByCategory: ToolCategory[] = [
       listConverter,
       tomlToJson,
       tomlToYaml,
+      hddCalculator,
       xmlToJson,
       jsonToXml,
       markdownToHtml,